JP2005142685A - Information recording/reproducing apparatus, reproducing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information recording/reproducing apparatus capable of carrying out smooth trick playback by alleviating a processing load imposed when only in-frame compression data are read from a multiplex stream recorded on a recording medium, and to provide a reproducing method and a program. <P>SOLUTION: Since the information recording reproducing apparatus controls the reading of in-frame compression image data from a recording medium on the basis of an information file including an identifier being a recording unit of a recording start position of the in-frame compressed image data on the recording medium and an offset from the head of the recording unit, the information recording reproducing apparatus can read the in-frame compressed image data from the recording medium without the need for a header analysis and a packet count or the like so as to alleviate the load on a control section. Further, the information recording reproducing apparatus can read the in-frame compressed image data from any position of a video stream. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an information recording / reproducing apparatus, a reproducing method, and a program for reproducing an MPEG2 stream recorded on a recording medium such as a hard disk drive (hereinafter referred to as HDD).

  In the HDD, continuous recording areas are divided into fixed block length units called sectors, and an ID is assigned to each sector. An OS (Operating System) such as Windows (registered trademark) manages consecutive N sectors in a unit called a cluster, and data reading / writing with respect to the HDD is performed in the cluster unit. That is, when a file larger than the cluster size is written to the HDD, one file data is divided and written into a plurality of clusters.

  FAT (File Allocation Tables) is known as a typical file system employed in a recording medium such as an HDD. FIG. 22 shows the configuration of the recording area of the HDD adopting this FAT file system. The HDD recording area includes a head area 201 in which a master boot record (MBR) or the like is recorded, a boot record (BR) in the beginning of a partition, file system information (FSI) or the like in an area 202, and a file An area 203 for recording actual data and areas 204 and 205 for a plurality of FAT management tables (FAT # 1, FAT # 2) are formed.

  Here, the FAT management table of FAT # 2 is a backup of the FAT management table of FAT # 1. In a randomly accessible recording medium such as an HDD, the free space is gradually distributed as data reading and writing is repeated, so there is no guarantee that the actual data of one file is necessarily written in a continuous cluster group. Rather, it is often written in a distributed manner.

  For example, as shown in FIG. 23, in a continuous cluster group (A, B,..., Y, Z, a, b, c,...), The actual data of one file is A, T, B, M, In some cases, L, F, S, V,... In the FAT, for example, as shown in FIG. 24, the number of each cluster in which the actual data of the file is written is managed together with the order in the FAT management table (FAT # 1, FAT # 2). Is configured to read the actual data of the target file by referring to the FAT management table (FAT # 1, FAT # 2).

  When the MPEG (Moving Picture Coding Experts Group) 2 stream is recorded in the HDD adopting the FAT file system as described above, and the MPEG2 stream is read out and reproduced from the HDD, a FAT management table as shown in FIG. The reproduction table 210 in which the cluster numbers in which the MPEG2 stream to be reproduced is recorded is registered in the reading order of the actual data is created on the main memory. Thereafter, the cluster number is sequentially read from the head of the reproduction table 210, the actual data is read from the HDD, decoded, and the MPEG2 stream is reproduced.

  By the way, in special reproduction (hereinafter referred to as trick play reproduction) such as fast forward reproduction and rewind reproduction, an I picture in a GOP is extracted from an MPEG2 stream and decoded reproduction is performed. At this time, in order to extract the I picture from the MPEG2 stream, the contents of the pack header and the system header in the MPEG2 stream must be analyzed in the same way as in the normal reproduction, and the time is shorter than in the normal reproduction. Therefore, there is a problem that a high-speed CPU is required to realize smooth trick play reproduction.

In Patent Literature 1, when content data is encrypted and recorded on a recording medium such as an optical disk, a random access point (time stamp and data read start address) of an MPEG2 video I picture is calculated, tabulated, and a map file A technique for performing trick play playback of video from the contents of this map file is disclosed. According to this technique, the reading start position of I picture data can be known without analyzing the contents of the pack header and system header in the MPEG2 stream, and the burden on the CPU can be reduced accordingly.
Republished patent publication WO01 / 015163

  However, in the technique of Patent Document 1, the position information represented by the address of the transport packet, that is, the number of packets from the head of the stream is obtained as a random access point of the I picture and registered in the map file. In order to detect the start position of the I picture on the recording medium during trick play reproduction, it is necessary to trace the number of packets by tracing successive transport packets, which imposes a processing burden. Further, since the random access point of the I picture is represented by the number of packets from the head of the stream, there is a restriction that the start position of the I picture cannot be detected from the middle of the stream.

  Further, the start of reading I-picture data needs to be performed by the map file, and the end of the I-picture data needs to be determined by, for example, detecting the end of the I-picture with an MPEG2 decoder. On the other hand, the data read from the recording medium is once buffered in the buffer memory and then supplied to the MPEG2 decoder. Therefore, when the end of the I picture is detected by the MPEG2 decoder, unnecessary data waiting for decoding may be accumulated in the buffer memory, that is, meaningless reading from the recording medium occurs. There is a risk that.

  The present invention has been made to solve such a problem, and reduces the processing load when only the compressed data in the frame is read from the multiplexed stream recorded on the recording medium, thereby enabling smooth trick play reproduction. An object of the present invention is to provide an information recording / reproducing apparatus, a reproducing method, and a program that can be performed.

  The present invention also provides an information recording / reproducing apparatus, reproducing method, and program capable of switching between stereo output and monaural output mode when reproducing an audio stream recorded on a recording medium without header analysis. The purpose is that.

  In order to achieve such an object, an information recording / reproducing apparatus according to the present invention has data obtained by multiplexing a video stream and an audio stream including intra-frame compressed screen data and inter-frame compressed screen data. A storage unit for storing an information file including an identifier of a recording unit of a recording start position on the recording medium and an offset from the beginning of the recording unit of at least a part of the frame-compressed screen data of the recorded recording medium And a control unit that performs control to read the screen data compressed in the frame from the recording medium based on the information file stored in the storage unit.

  In the present invention, the screen compressed in the frame from the recording medium based on the information file including the identifier of the recording unit of the recording start position on the recording medium of the screen data compressed in the frame and the offset from the head of the recording unit. Since control is performed so that data is read out, screen data compressed in a frame can be read from the recording medium without performing header analysis or packet count, and the burden on the control unit can be reduced. Also, reading of screen data compressed in a frame can be started from any position in the video stream.

  Further, the identifier of the recording unit at the recording start position of the information file and the offset from the head of the recording unit can be specifically the sector ID and the offset from the head of the sector. Further, it may be a cluster ID and an offset from the head of the cluster.

  The information recording / reproducing apparatus of the present invention further includes a reproducing unit that decodes the intra-frame compressed screen data read from the recording medium by the control unit and continuously reproduces it.

  In this invention, since the burden on the control unit when reading the screen data compressed in the frame from the recording medium is reduced, trick play playback such as fast forward playback and rewind playback based on the screen data compressed in the frame. Can be performed smoothly.

  In the information recording / reproducing apparatus of the present invention, the information file includes mode information that defines whether the audio stream recorded on the recording medium is output in stereo or monaural, and is stored in the screen data compressed in the frame. It is associated with the identifier of the recording start position on the recording medium and the offset information from the beginning of the recording unit, and the control unit reads out the audio stream from the recording medium and reproduces the audio, and the mode information of the information file The function of determining the timing of switching the audio output mode based on the above.

  According to the present invention, audio mode information can be obtained during audio playback without analyzing the header. Thereby, it is possible to reduce the burden on the control unit when the audio stream is read from the recording medium and the audio is reproduced.

  More specifically, the intra-frame compressed screen data is an I picture in an MPEG2 stream. This makes it possible to selectively read and decode only the I picture from the recording medium and perform trick play playback such as fast forward playback and rewind playback.

  An information recording / reproducing apparatus according to a different aspect of the present invention provides a recording medium on which data obtained by multiplexing a video stream including an intra-frame compressed screen data and an inter-frame compressed screen data and an audio stream is recorded. A storage unit for storing an information file including information on a recording start position and a recording end position on a recording medium of at least a part of the frame-compressed screen data, and recording based on the information file stored in the storage unit And a control unit that performs control so as to read out the frame-compressed screen data from the medium.

  In the information recording / reproducing apparatus of the present invention, the screen data compressed in the frame can be read from the recording medium without performing header analysis or packet count. Also, since not only the recording start position of the in-frame compressed data on the recording medium but also the recording end position can be obtained from the information file, the recording medium can be recorded without waiting for detection of the end of the screen data compressed in the frame by the decoding process. Reading of data from the recording medium can be terminated, and meaningless reading of data from the recording medium does not occur. Thereby, the burden of a control part can be reduced.

  Specifically, the information of the recording start position and the recording end position of the information file can be respectively set as a sector ID and an offset from the head of the sector. Further, it may be a cluster ID and an offset from the head of the cluster.

  The information recording / reproducing apparatus of the present invention further includes a reproducing unit that decodes the intra-frame-compressed screen data read from the recording medium by the control unit and continuously reproduces it.

  In the present invention, since the burden on the control unit when reading screen data compressed in a frame from a recording medium is reduced, trick play playback such as fast forward playback and rewind playback based on the screen data compressed in the frame. Can be performed smoothly.

  In the information recording / reproducing apparatus of the present invention, the information file includes mode information that defines whether the audio stream recorded on the recording medium is output in stereo or monaural, and is stored in the screen data compressed in the frame. It is associated with the identifier of the recording start position on the recording medium and the offset information from the beginning of the recording unit, and the control unit reads out the audio stream from the recording medium and reproduces the audio, and the mode information of the information file The function of determining the timing of switching the audio output mode based on the above.

  According to the present invention, audio mode information can be obtained during audio playback without analyzing the header. Thereby, it is possible to reduce the burden on the control unit when the audio stream is read from the recording medium and the audio is reproduced.

  Also in the information recording / reproducing apparatus of the present invention, the intra-frame compressed screen data is more specifically an I picture in an MPEG2 stream. This makes it possible to selectively read and decode only the I picture from the recording medium and perform trick play playback such as fast forward playback and rewind playback.

  Also, a playback method according to another aspect of the present invention is a recording method in which data obtained by multiplexing a video stream including an intra-frame compressed screen data and an inter-frame compressed screen data and an audio stream is recorded. A method for reproducing a medium, wherein an information file including an identifier of a recording unit of a recording start position on a recording medium of at least a part of the frame-compressed screen data and an offset from the head of the recording unit is stored in a storage unit In addition, on the basis of the information file stored in the storage unit, the screen data compressed in the frame is read from the recording medium, decoded, and continuously reproduced.

  In the present invention, the screen compressed in the frame from the recording medium based on the information file including the identifier of the recording unit of the recording start position on the recording medium of the screen data compressed in the frame and the offset from the head of the recording unit. Since the data is read out, the screen data compressed in the frame can be read from the recording medium, decoded and continuously reproduced without performing header analysis or packet count, and the load on the control unit can be reduced. Also, trick-play playback can be started by starting to read out the frame-compressed screen data from any position in the video stream.

  In the playback method of the present invention, the information file stored in the storage unit is compressed in-frame with mode information that defines whether the audio stream recorded on the recording medium is output in stereo or monaural. Information associated with the identifier of the recording unit of the recording start position on the recording medium of the recorded screen data and the offset information from the beginning of the recording unit, and when reproducing the audio by reading the audio stream from the recording medium The timing for switching the audio output mode is determined based on the mode information of the file.

  According to the present invention, audio mode information can be obtained during audio playback without performing header analysis or the like. Thereby, it is possible to reduce the burden on the control unit when the audio stream is read from the recording medium and the audio is reproduced.

  Also, a playback method according to another aspect of the present invention is a recording method in which data obtained by multiplexing a video stream including an intra-frame compressed screen data and an inter-frame compressed screen data and an audio stream is recorded. A method for reproducing a medium, wherein an information file including information on a recording start position and a recording end position on a recording medium of at least a part of frame-compressed screen data is stored in a storage unit, and stored in the storage unit Based on the stored information file, the frame-compressed screen data is read from the recording medium, decoded, and continuously reproduced.

  According to the reproducing method of the present invention, screen data compressed in a frame can be read from a recording medium, decoded, and reproduced without performing header analysis or packet count. Also, since not only the recording start position of the in-frame compressed data on the recording medium but also the recording end position can be obtained from the information file, the recording medium can be recorded without waiting for detection of the end of the screen data compressed in the frame by the decoding process. Reading of data from the recording medium can be terminated, and meaningless reading of data from the recording medium does not occur. Thereby, the burden of a control part can be reduced.

  Furthermore, a program according to another aspect of the present invention provides a computer that externally transmits data in which a video stream including an intra-frame compressed screen data and an inter-frame compressed screen data and an audio stream are multiplexed. Transfer means for transferring to the recording medium of the information recording / reproducing apparatus connected to the computer, and accessing the recording medium of the information recording / reproducing apparatus connected to the computer, and at least a part of the frames recorded in the recording medium is compressed in the frame Information file creation means for creating an information file including an identifier of the recording unit at the recording start position of the screen data recording medium and an offset from the beginning of the recording unit, and information recording and reproduction of the information file created by the information file creation means It functions as an information file transfer means for transferring to a device. That.

  According to the program of the present invention, in the information recording / reproducing apparatus connected to the outside, information including the identifier of the recording unit of the recording start position on the recording medium of the screen data compressed in the frame and the offset from the head of the recording unit Based on the file, the screen data compressed in the frame is read from the recording medium, decoded and continuously played back, so the screen data compressed in the frame from the recording medium without performing header analysis or packet count etc. Can be read and decoded, and trick play reproduction such as fast forward reproduction and rewind reproduction can be performed, and the burden on the control unit can be reduced. Further, in the information recording / reproducing apparatus connected to the outside, reading of the screen data compressed in the frame can be started from any position in the video stream.

  In the program of the present invention, the information file creating means compresses the mode information that defines whether the audio stream recorded on the recording medium of the information recording / reproducing apparatus is output in stereo or monaural, within the frame. The screen data is recorded in the information file in association with the identifier of the recording unit at the recording start position on the recording medium and the offset information from the beginning of the recording unit. Thereby, in the information recording / reproducing apparatus connected to the outside, the mode information described in the header of the MPEG2 stream can be obtained without header analysis by the control unit, and the MPEG2 stream is read from the recording medium and the audio is reproduced. The burden on the control unit can be reduced.

  A program according to another aspect is configured to connect a computer with data obtained by multiplexing a video stream including an intra-frame compressed screen data and an inter-frame compressed screen data and an audio stream. Transfer means for transferring to the recording medium of the recorded information recording / reproducing apparatus, and the recording medium of the information recording / reproducing apparatus connected to the computer to access at least a part of the intra-frame compressed screen data recorded on the recording medium. Functions as information file creation means for creating an information file including information on the recording start position and recording end position on the recording medium, and information file transfer means for transferring the information file created by the information file creation means to the information recording / reproducing apparatus It is characterized by making it.

  According to the program of the present invention, the information recording / reproducing apparatus connected to the outside can read the screen data compressed in the frame from the recording medium without performing header analysis or packet count. Also, since not only the recording start position of the in-frame compressed data on the recording medium but also the recording end position can be obtained from the information file, the recording medium can be recorded without waiting for detection of the end of the screen data compressed in the frame by the decoding process. Reading of data from the recording medium can be terminated, and meaningless reading of data from the recording medium does not occur. Thereby, the burden of a control part can be reduced.

  According to the information recording / reproducing apparatus, the reproducing method, and the program of the present invention, it is possible to reduce the processing load when only the intra-frame compressed data is read from the multiplexed stream recorded on the recording medium, thereby enabling smooth trick play reproduction. Become. Further, it is possible to switch between stereo output and monaural output mode when reproducing an audio stream recorded on a recording medium without header analysis by the control unit, and the burden on the control unit can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing the appearance of a portable HDD video playback device according to an embodiment of the present invention, FIG. 2 is a plan view showing the same portable HDD video playback device 100 from the front, and FIG. Similarly, FIG. 4 is a plan view of the portable HDD video playback device as seen from above.

  The portable HDD video playback device 100 has a housing 1 that is sized to be held with one hand. On the front side of the housing 1, an LCD screen portion 2, a key operation portion 3, operation buttons 4, and an LED (Light Emitting Diode) display portion 5 for displaying various states are provided.

  As shown in FIG. 2, the key operation unit 3 includes three keys 31, 32, and 33 that are arranged concentrically with each other and can be individually operated. The key at the center is an ENTER key 31 for designating selection / execution. The keys outside the ENTER key 31 are menu selection-related keys 32 that are used when a menu is selected. Further, the outer keys are reproduction-related keys 33 used at the time of reproduction.

  Each of the menu selection related key 32 and the reproduction related key 33 is configured such that a corresponding key command is generated by pressing each of the upper, lower, left and right positions around the ENTER key 31. The key command generated by the menu selection related key 32 is, for example, shifting the focus position up / down / left / right to select an item on various menu screens to be described later. Key commands generated by the reproduction-related key 33 are fast-forwarding, rewinding, and increasing / decreasing the audio volume.

  The operation button 4 includes a SETUP button 41 for calling up various setting screens, a DISPLAY button 42 for displaying the elapsed playback time (remaining time) of the video stream, and playback for instructing playback start and pause. There are a button 43 and a stop button 44 for instructing to stop the reproduction.

  The LED display unit 5 includes a power-on display unit 51 that displays a power-on state, a charge display unit 52 that displays that the battery is being charged, and a busy display unit 53 that displays a busy state such as during stream transfer.

  On one side surface of the housing 1, a DCIN jack 6 for connecting a DC power source, a USB connector 7 for connecting a USB (Universal Serial Bus), and an AVOUT jack 8 for AV output are provided in this order from the top. . A strap attaching portion 9 is also provided. A PWR key (not shown) for ON / OFF operation of the main power source is provided on the other side surface portion of the housing 1. As shown in FIG. 4, a headphone jack 10 and a number of slit-shaped exhaust holes 11 are provided side by side on the upper surface of the housing 1. A number of slit-shaped intake holes 12 are arranged in the lower portion of the housing 1.

  FIG. 5 is a view showing only the housing 1 in the cross-sectional view of FIG. 3. As shown in the figure, the casing 1 is composed of a casing part 1A on the front side, an intermediate casing part 1B, and a casing part 1C on the back side. The front-side casing component 1A and the back-side casing component 1C are casing components that mainly form the front and the back of the outer shape of the portable HDD video playback device 100, respectively. The intermediate housing part 1B has a portion which becomes the upper side surface and the left and right side surfaces of the outer shape of the portable HDD video playback device 100, and the portion which becomes the upper side surface of the housing 1 is as shown in FIG. The exhaust hole 11 is provided in the above. The front housing part 1A and the rear housing part 1C are joined to each other with the intermediate housing part 1B interposed therebetween. A semicircular cross-sectional shape portion 15 is formed in the lower portion of the housing 1, and the front-side housing component 1 </ b> A and the rear-side housing component 1 </ b> C are directly butted to each other. Yes. Further, the intake hole 12 is provided on the housing part 1 </ b> A side on the front side of the semicircular cross-section 15. The lower part of the intermediate casing part 1B is bent into a U-shaped cross section following the semicircular cross-sectional shape part 15 at the lower part of the casing 1. This portion is referred to as a bent portion 14 of the intermediate casing component 1B.

  A transparent acrylic cover 35 that can cover the LCD screen portion 2 and the operation buttons 4 can be attached to and detached from the front side of the housing 1, and the acrylic cover 35 allows the LCD screen portion 2 to be removed. It protects against scratches and dust. The acrylic cover 35 is provided with an opening 36 for exposing a portion of the key operation unit 3, and the key operation unit 3 can be operated with the acrylic cover 35 attached.

  Next, the internal structure of the portable HDD video playback device 100 will be described.

  As shown in FIG. 3, the components in the housing 1 are divided into a component group housed in an upper position and a component group housed in a lower position in the height direction of the portable HDD video playback device 100. It is divided in arrangement. The component group housed in the upper position includes the LCD 21 with backlight, the main board 22, the HDD board 23, the HDD 24, the cooling fan 25, and the like, and the component group housed in the lower position includes the composite inverter board. 26, battery pack 27, and the like. The LCD 21, the main board 22, and the HDD 24 housed in the upper position are main heat sources in the portable HDD video playback device 100. When comparing the heat generation amounts, the order of LCD 21> main board 22> HDD 24 is given. It is common to become.

  In this portable HDD video playback device 100, these main heat source components are arranged in order from the one with the highest heat generation from the front side to the back side. By selecting such an arrangement, the heating of the casing component 1C on the back side can be suppressed to the lowest level compared to other arrangement orders. The portable HDD video playback device 100 is designed so that a user can enjoy watching a video by holding it in his / her hand, and the user's hand is in contact with the housing part 1C on the rear side on the widest surface during viewing. Thus, the degree of temperature discomfort due to heat can be reduced by minimizing the temperature rise of the housing component 1C on the back side.

  Further, the heat in the housing 1 is generated from an intake hole 12 provided in a lower portion of the housing 1 which is generated by a cooling fan 25 disposed at the uppermost portion in the housing 1. The air is discharged to the outside by an air flow through the exhaust hole 11. Thereby, since the heat generating source in the housing 1 is efficiently air-cooled, the heat problem for the user is further reduced.

  A battery pack 27 for power supply is disposed inside the U-shaped bent portion 14 of the intermediate casing component 1B so as to be surrounded by the bent portion 14. Further, a composite inverter board 26 is supported on the front side (screen side) of the flat surface on the tip side of the bent portion 14. That is, the battery pack 27 and the composite inverter board 26 are separated by the bent portion 14 of the intermediate casing component 1B. Here, the composite inverter board 26 is a board on which components related to the operation of the operation buttons 4 and the key operation unit 3 and an inverter for driving the backlight of the LCD 21 are mounted. As described above, since the battery pack 27 and the composite inverter board 26 are separated by the bent portion 14 of the intermediate casing component 1B, the influence on the composite inverter board 26 due to the liquid leakage from the battery pack 27 can be avoided. In addition, it is possible to protect the battery pack 27 by avoiding that the pressure when the key operation unit 3 is operated is directly applied to the battery pack 27.

  Since the battery pack 27 does not serve as a large heat source, there is no problem even if the battery pack 27 is disposed near the lower back where the user's hand most frequently touches. In addition, since the battery pack 27 has the highest specific gravity among the components in the housing 1 and the weight is large, the battery pack 27 is arranged at the bottom of the housing 1 so that the user can hold the portable HDD video playback device 100 during viewing. The feeling of stability when held with is improved.

  In the portable HDD video playback device 100 of this embodiment, the air intake hole 12 is provided in the lower part of the housing 1 as shown in FIG. 3, but as shown in FIG. The intake hole 12 may be provided at a position immediately above the battery pack 27.

  FIG. 13 is a plan view showing the internal structure of the portable HDD video playback device 100 for each layer. The backlight of the LCD 21 is connected to the connector 132 fixed to the screen side surface of the composite inverter board 26 through the connection wiring 131, and signals necessary for lighting and control are transmitted from the composite inverter board 26 to the backlight of the LCD 21 through the connection wiring 131. Supplied. The LCD 21 is connected to a connector 134 fixed to the opposite side of the screen of the main board 22 through the connection wiring 133, and necessary signals are supplied from the main board 22 to the LCD 21 through the connection wiring 133. The main board 22 and the composite inverter board 26 are electrically connected through connectors 135 and 136 fixed to the side surfaces of the respective screens and connection wires 137 connected between the connectors 135 and 136, so that necessary signals can be communicated with each other. Do. Further, two connectors 140 and 141 to which one ends of connection wirings 138 and 139 for supplying drive signals to the two cooling fans 25 and 25 are respectively connected are provided on the screen side surface of the main board 22. The main board 22 and the HDD board 23 communicate with each other by a connection wiring 144 that connects between a connector 142 provided on the opposite side of the screen of the main board 22 and a connector 143 provided on the side of the screen of the HDD board 23. It can be done. The main board 22 is provided with a DC (direct current) IN jack 6, a USB connector 7, an AVOUT jack 8 for AV output, and a headphone jack 10. The HDD board 23 is provided with a switch 145 for resetting the system. The connection wiring 146 drawn out from the battery pack 27 is connected to a connector 147 provided on the side surface of the main board 22. The HDD 24 is electrically connected to the HDD substrate 23 through a connector 148 provided on the opposite side of the screen of the HDD substrate 23.

  Next, the electrical configuration of the portable HDD video playback device 100 will be described with reference to FIG. The figure mainly shows the configuration of a circuit mounted on the main board 22.

  In the figure, the system controller 61 includes various operation keys 3 and 4, operation of the PWR key 62, connection of AC (alternating current) power (AC detection) 63, output of the reset IC 64, voltage of the battery 65, The temperature sensor 66 and the like are monitored, and processing corresponding to the monitoring result is executed. The reset IC 64 is an IC that generates a reset operation signal when the reset SW 67 is operated.

  When the system controller 61 detects that the PWR key 62 has been pressed, the system controller 61 performs system startup processing and initializes each device to an operable state. Further, control is performed so that the power-on display unit 51 is lit. When it is detected that the PWR key 62 has been pressed while the system is operating, a system termination process is performed.

  When the system controller 61 receives a reset operation signal from the reset IC 64, the system controller 61 performs a startup process following a reset process, that is, an end process.

  When the system controller 61 detects connection of AC power (AC detection) 63, the system controller 61 controls the power circuit 68 and controls charging of the battery 65. The power supply circuit 68 is automatically turned off when, for example, a high temperature equal to or higher than a set temperature is detected based on the output of a temperature sensor 69 disposed in the vicinity thereof.

  The system controller 61 calculates the remaining amount of the battery 65 based on the monitoring result of the battery voltage and controls the battery remaining amount display on the screen.

  The system controller 61 controls the rotation speed of the cooling fan 25 based on the output of the temperature sensor 66. That is, control is performed to increase the cooling capacity in proportion to the temperature.

  Further, the system controller 61 monitors key operations of the key operation unit 3 and the operation buttons 4 and performs event processing according to the type of the operated key.

  The system controller 61 includes a CPU (Central Processing Unit) 71, a RAM (Random Access Memory) 72, a ROM (Read Only Memory) 73, an A / D conversion circuit 74, a serial PWM (Pulse Width Modulation) control control circuit 75, and the like. These are connected through a bus 76. The CPU 71 executes various arithmetic processes and controls using the RAM 72 as a work area by firmware stored in the ROM 73. The A / D conversion circuit 74 operates the above-described various keys 3 and 4, operation of the PWR key 62, connection of AC power (AC detection) 63, output of the reset IC 64, voltage of the battery 65, temperature sensor 66 This is a part that converts an analog value, which is a monitoring result, into a digital value. The serial PWM control circuit 75 supplies a mute control for the headphone 81 and a PWM signal for controlling the luminance of the backlight 82 of the LCD 21 to the inverter 83.

  The USB bridge 86, HDD 24, and DMA (Direct Memory Access) transfer circuit 87 to which the USB terminal 85 is connected are connected to each other through an IDE (Integrated Drive Electronics) bus 88 and transferred from a PC connected to the USB terminal 85. Data such as a video stream is recorded on the HDD 24 from the USB bridge 86 through the IDE bus 88.

  The DMA transfer circuit 87 is a circuit that transfers data read from the HDD 24 to the MPEG2 decoder 89. The DMA transfer circuit 87 has four selectors 90, 91, 92, 93 and a DMA controller 94. The first selector 90 is a selector for selecting data on the IDE bus 88, and connects the DMA transfer circuit 87 to the IDE bus 88 based on an ATA (AT Attachment) command for the system controller 61 to access the HDD 24. Put it in a state. The first selector 90 is connected to the second selector 91 connected to the buffer memory 95 by the first DMA transmission path 96. Therefore, the data extracted from the IDE bus 88 by the first selector 90 is transferred to the buffer memory 95 through the first DMA transmission path 96 and the second selector 91.

  In the data transfer from the HDD 24 to the buffer memory 95, the system controller 61 controls the issuance timing of the ATA command output to the first selector 90 so that the data reading from the HDD 24 is performed intermittently. . Specifically, for example, data is read from the HDD 24 in units of a video stream for a predetermined playback time and transferred to the buffer memory 95. When the data in the buffer memory 95 becomes empty, the next playback time is read from the HDD 24. The ATA command is issued from the system controller 61 to the first selector 90 so as to read the video stream. As a result, access to the HDD 24 is intermittently performed, and the amount of heat generated by the HDD 24 and power consumption can be reduced.

  Data such as video stored in the buffer memory 95 is read out by the second selector 91 when a video stream for a predetermined reproduction time is stored in the buffer memory 95, and the second selector 91 and the MPEG2 decoder 89 are read out. Are transferred to the MPEG2 decoder 89 through the second DMA transmission line 97 connecting the two. The MPEG2 decoder 89 is a circuit that decodes a video stream encoded by MPEG2 by hardware. The SDRAM 98 is a randomly accessible memory used as a work area of the MPEG2 decoder 89.

  Of the output of the MPEG2 decoder 89, the video data is sent to the LCD controller 99, and the LCD controller 99 controls the driving of the LCD 21 to reproduce the video. On the other hand, the audio data output from the MPEG2 decoder 89 is converted into an analog signal by the D / A converter 101 and then sent to the headphones connected to the headphone terminal 10. Also, an external television or the like can be connected to the AVOUT terminal 102. When an external television is connected to the AVOUT terminal 102, the analog signal of the D / A converter 101 is output from the linear amplifier 103. It is amplified to the required level.

  The third selector 92 of the DMA transfer circuit 87 performs communication between the system controller 61 and the bus 105 to which the flash ROM 104 is connected. The third selector 92 extracts the ATA command generated from the system controller 61 from the bus 105 and notifies the first selector 90 through the control line 106.

  The HDD 24 stores, as read-only data, data such as bitmaps and character codes, which are components such as a title list, menu, and setting screen. When the system controller 61 reads out this bitmap and character code from the HDD 24, it notifies the DMA controller 94 through the third selector 92. Upon receiving this notification, the DMA controller 94 enables the DMA transmission path 96 between the third selector 92 and the second selector 91 and controls the fourth selector 93 to control the second selector 91 and The third DMA transmission path 107 connecting the MPEG2 decoder 89 is made valid.

  The character code read from the HDD 24 and held in the buffer memory 95 together with the bit map is sent to the system controller 61 through the second selector 91, the third selector 92, and the bus 105. The system controller 61 reads bitmap data corresponding to this character code from the flash ROM 104 and returns it to the third selector 92. The DMA controller 94 sends bitmap data corresponding to the character code returned from the system controller 61 from the third selector 92 to the fourth selector 93, and the bitmap read out from the buffer memory 95 through the second selector 91. And control to output to the MPEG2 decoder 89.

  The third DMA transmission path 107 has a wider bus width than the second DMA transmission path 97 for bitmap transmission. For example, the second DMA transmission line 97 is composed of 8 data lines and 4 control lines, whereas the third DMA transmission line 107 is 16 data lines, 24 address lines, It consists of three control lines. This prevents a great difference in the user's perceived speed between the playback of the video stream and the playback of the bitmap.

  Next, a transfer application applied to a PC (Personal Computer) in order to use the portable HDD video playback device 100 will be described.

  FIG. 7 shows a display window 201 of recorded content displayed on the PC by this transfer application. In the recorded content display window 201, a list of the names, creation dates and times of recording, etc. of each video stream recorded on the PC or reserved for recording is displayed in the order of recording / recording reservation, for example. Displayed from top to bottom.

  When it is desired to transfer a desired video stream to the portable HDD video playback device 100, a transfer window 202 is called, and the desired video stream in the recorded content display window 201 is dragged and dropped with a mouse. By the operation, it is dropped into the transfer video stream list display box 203 in the transfer window 202. As a result, information on the video stream is displayed in the transfer video stream list display box 203. Thereafter, by clicking the transfer button 204 in the transfer window 202 with a mouse, if the portable HDD video playback device 100 is connected to the PC, a video stream from the PC to the portable HDD video playback device 100 is displayed. Transfer begins immediately. If the portable HDD video playback device 100 is not connected to the PC when the transfer button 204 is clicked with the mouse, the transfer of the video stream is started as soon as the portable HDD video playback device 100 is connected. It has become.

  Here, various formats such as AVI (Audio Video Interleaved) and WMV (Windows (registered trademark) Media Video) are known for the video stream stored in the PC. Since the portable HDD video playback device 100 is designed to decode and play back a video stream in the MPEG2 format, the transfer application must transfer the video stream from the PC to the portable HDD video playback device 100 before transferring the video stream. The video stream format is automatically converted to MPEG2, and the video stream converted to MPEG2 is automatically transferred from the PC to the portable HDD video playback apparatus 100.

  The above is the operation when the user manually transfers a desired video stream. This video content has a capacity of several G (giga), and a considerable time is expected for data transfer. Therefore, this transfer application is provided with a transfer reservation function. When this transfer reservation function is used, the automatic transfer button 205 in the transfer window 202 is clicked with the mouse. Then, a window for designating the time for starting the automatic transfer is displayed, and the transfer start time desired by the user can be input and determined here. The transfer application stores the transfer start time specified by the user, and displays it in the transfer video stream list display box 203 in the transfer window 202 when the specified time is reached as compared with the clock time. Each video stream is transferred from the PC to the portable HDD video playback device 100 through format conversion.

  Note that the video streams displayed in the transfer video stream list display box 203 in the transfer window 202 are transferred in order from the top. The display order of the video stream can be freely changed by clicking the order change buttons 206 and 207 with a mouse. That is, after selecting the video stream whose order is to be changed with the mouse, clicking the order change button 206 once moves the order of the selected video stream up by one, and conversely, the order change button 207 is pressed once. By clicking, the order of the selected video stream is moved down by one. Further, by selecting the selected video stream to be deleted with the mouse and clicking the delete button 208, it is possible to delete the selected video stream from the transfer video stream list display box 203 and remove it from the transfer target. .

  Next, operations and operation screens of the portable HDD video playback device 100 will be described. FIG. 14 shows a processing procedure from power-on to video playback start.

  When the user presses the PWR key of the portable HDD video playback device 100, this is detected by the system controller 61, and the system controller 61 initializes each device in accordance with the firmware stored in the ROM 73 (step 1401). ). Thereafter, the built-in timer is started (step 1402). Subsequently, the transfer of the video stream is started from the PC connected via USB to the portable HDD video playback device 100. When the transfer is completed, the portable HDD video playback device 100 uses the transfer completion notification from the PC as an external interrupt. Receive (step 1403). When the portable HDD video playback device 100 receives an external interrupt, it starts menu processing for creating and displaying a menu to be displayed on the screen (step 1404).

  First, an action menu 301 as shown in FIG. 8 is created and displayed. The action menu 301 displays information 302 on the video stream such as the title name, creation date and time, and recording time of the last played video stream, and items 303 to 307 indicating selectable action types. It is like that. Action types include “return to title list display”, “play from continuation”, “play from the beginning”, “delete”, “fold claw”, and the like. The focus 308 is located in one of these items 303 to 307, and the user can freely shift the position of the focus 308 up and down by operating the menu selection related key 32 of the key operation unit 3. it can. The initial position of the focus 308 is always in the item “play from continuation”, so that the viewing of the video stream from the time when the previous playback was interrupted can be started immediately without the focus 308 shifting operation. That is, after the action menu 301 is displayed immediately after the system is started, the user can watch the video stream from the time when the previous playback was interrupted by pressing the ENTER key 31 of the key operation unit 3 as it is.

  When the focus is shifted to the item “return to title list display” and the ENTER key 31 of the key operation unit 3 is pressed, a title list 401 as shown in FIG. 9 is displayed instead of the action menu 301. . In this title list 401, title items 402 to 408 of all video streams recorded in the HDD 24 of the portable HDD video playback device 100 are displayed. The focus 409 is positioned in one of the title items 402 to 408, and the user freely moves the position of the focus 409 up and down by operating the menu selection related key 32 of the key operation unit 3. be able to. The initial position of the focus 409 is always in the item of the last reproduced title, so that the user can recognize the last viewed title. The user can view another title by moving the focus to the title item to be viewed from the title list 401 by operating the menu selection related key 32 and pressing the ENTER key 31.

  Returning to the flowchart of FIG. 14, when the user selects a title to be viewed as described above (step 1405), reading of the title video stream from the HDD 24 is started (step 1406). Then, playback processing of the video stream read from the HDD 24 is performed (step 1407). That is, the video stream read from the HDD 24 is DMA-transferred to the buffer memory 95 and buffered, and then DMA-transferred to the MPEG2 decoder 89 for decoding. The LCD controller 99 drives the LCD 21 based on the video data output from the MPEG2 decoder 89, whereby the video is displayed on the screen of the LCD 21. On the other hand, the audio data decoded by the MPEG2 decoder 89 is converted into an analog signal by the D / A converter 101 and then sent to the headphones connected to the headphone terminal 10 (step 1407).

  When the item “reproduce from the beginning” 305 in the action menu 301 is selected by the user, the video stream of the last reproduced title is reproduced from the beginning.

  When the “delete” item 306 is selected by the user in the action menu 301, the HDD 24 is deleted from the video stream of the title reproduced last. That is, the video stream of the title that has been viewed can be deleted from the HDD 24 with a few operations.

  When the “fold” tab item 307 in the action menu 301 is selected by the user, the corresponding video stream recorded in the HDD 24 is protected against deletion.

  Next, the environment setting screen will be described. FIG. 10 shows a screen 501 for setting the environment. This environment setting screen 501 can be called by pressing the SETUP button 41, for example. On the environment setting screen 501, various settings relating to display, various settings relating to audio, and the like can be performed. This environment setting screen 501 displays a display setting icon 502, an audio setting uncon 503, other icons 504, etc., and one of the icons 502 to 504 is selected as a menu selection-related key. The focus can be moved by the operation 32 and can be designated by the ENTER key 31. Display settings include backlight brightness adjustment 505, hue 506, color density 507, picture 508, contrast 509, alarm 510, and the like. Selection of each setting item can also be performed by moving the focus by operating the menu selection related key 32 and the ENTER key 31.

  Here, the alarm 510 sets a remaining time arbitrarily set by the user in a timer, and as shown in FIG. 11, the remaining time 511 is always displayed on a part of the screen during playback of a video stream or the like. When the remaining time becomes zero, for example, the alarm audio is synthesized with the audio during video playback and output. Since characters at the time of broadcasting may be inserted in television broadcasting or the like, it is easy for the user to make a mistake in the current time when watching on the portable HDD video playback device 100, and to pass over on a train or the like. Conceivable. By using the alarm function described above, the user can learn about the passage of the set time from the alarm while immersing himself / herself in viewing the video content, and can prevent overtime on a train or the like.

  FIG. 11 shows an example of a screen 602 that displays the elapsed playback (remaining) time 601 of the video stream. The playback elapsed (remaining) time 601 of the video stream is displayed as a numerical value 602 and an image 603 on the video stream being played, for example, by pressing the DISPLAY button 42.

  During playback of a video stream, the playback-related key 33 can be operated to fast-forward playback, rewind, increase / decrease the audio volume, and the like. As shown in FIG. 2, the playback-related key 33 performs fast-forward playback by pressing the right position, and performs rewind playback by pressing the left position. When the position on the right side of the playback-related key 33 is pressed once, fast-forward playback for a predetermined time (for example, 15 seconds) is executed, and the key is pressed while being pressed for a predetermined time. Continuous fast-forward playback is performed. Further, when the continuous fast-forward playback is started and further pressed for a certain time, the fast-forward speed is increased. Specifically, the speed of the first continuous fast-forward playback is set to 15 times speed, and then switched to 60 times speed.

  When the position on the left side of the playback-related key 33 is pressed once, rewind playback is performed for a predetermined time (for example, 15 seconds), and the key is pressed by continuing to press it for a predetermined time. During this time, continuous rewind playback is performed. Furthermore, the rewind speed is increased when the button is continuously pressed for a certain time after the continuous rewind playback is started. Specifically, the speed of the first continuous rewind playback is set to 15 times speed, and then switched to 60 times speed.

  The fast forward playback and rewind playback are performed using an I picture information file created by an I picture information file generation function installed in a transfer application.

  Next, the function for generating the I picture information file will be described in detail.

  When transferring the MPEG2 stream to the portable HDD video playback device 100, the transfer application creates such an I picture information file and transfers it to the HDD 24 of the portable HDD video playback device 100.

  FIG. 15 is a diagram showing the configuration of the I picture information file 111. As shown in FIG. The I picture information file 111 is created, for example, for all I pictures or I pictures having a period required for fast forward playback and rewind playback at 15 times speed and 60 times speed in trick play playback.

  The I picture information file 111 includes information 112 indicating a real address of the I picture on the HDD 24, a time stamp 113, and audio output mode information 114. The information 112 indicating the actual address of the I picture on the HDD 24 includes the sector ID indicating the recording start position of the I picture and the offset from the sector head, and the sector ID and the sector starting position indicating the recording end position of the I picture. Of offset. The time stamp 113 is time data on video. The audio output mode information 114 is information that defines whether audio is output in stereo or monaural.

  Next, a method for creating the I picture information file 111 will be described.

  FIG. 16 is a flowchart showing a procedure for creating the I picture information file 111, FIG. 17 is a block diagram of the MPEG2 system stream 120, FIG. 18 is a block diagram of the MPEG2 video stream 130, and FIG. 19 is a block diagram of the MPEG2 audio stream 140. It is. Hereinafter, these streams 120, 130, and 140 are collectively referred to as "MPEG2 stream".

  As shown in these drawings, the MPEG2 streams 120, 130, and 140 are composed of a plurality of packs 121. The first pack 121 is composed of a pack header 115, a system header 116, and subsequent packets 117. The subsequent pack 121 is composed of a pack header 115 followed by a packet 117 group. An end code 118 is inserted in the last part of the last pack. As shown in FIG. 17, the pack header 115 includes a pack start code, “01”, SCR, multiplexing rate, and stuffing byte. The system header 116 includes a system header start code, header length, bit rate, number of audio channels, 4 flags, number of video channels, reserved bytes, and N-loop individual stream information. The four flags include a fixed flag, a CPS flag, an audio lock flag, a video lock flag, and a “1” marker bit. The N-loop individual stream information includes a stream ID, “11”, a buffer area scale, a buffer area size, and the like.

  After the transfer of the MPEG2 file to the HDD 24 is completed, the PC reads the contents of the cluster including the MPEG2 file from the HDD 24 while referring to the FAT management table by the I picture information file generation function of the transfer application. The pack header 115 and the system header 116 of the MPEG2 stream 120, 130, 140 shown in FIG. 19 are analyzed (step 1601), and the packet 117 is acquired from the MPEG2 stream 120, 130, 140 based on the analysis result (step 1601). 1602).

  Subsequently, the PC analyzes the acquired packet 117 and determines whether the packet 117 is a video packet, an audio packet, or a file end (step 1603).

  As shown in FIG. 18, a video packet 117 is composed of an SH (Sequence Header) 119 and a GOP (Group Of Pictures) 122 arranged thereafter. The GOP 122 is composed of a plurality of three types of pictures of I (Intra), P (Predictive), and B (Bidirectionally), and an I picture is arranged at the head of the GOP 122. This I picture is screen data compressed (intra-frame compression) only with information in the own screen. The P picture is temporally represented by the correlation information from the past screen (interframe compression), and the B picture is represented by the correlation information from the temporally preceding and following screens (interframe compression). ) Screen data. Therefore, it can be said that the I picture is data capable of decoding and reproducing the screen data alone. On the other hand, as shown in FIG. 19, the audio packet 117 includes a header 123, an error check 124, and audio data 125. The header 123 includes a bit 126 indicating the output mode (stereo / monaural) of the audio data 125.

  If the acquired packet 117 is a video packet, the PC attempts to extract the SH 116 from the acquired packet (step 1604). If the SH 116 cannot be extracted, the PC returns to step 1602 to acquire the next packet 117. . When the SH 116 can be extracted, the real address (sector ID and offset from the head of this sector) on the head HDD 24 of the I picture located at the head of the GOP 122 following the SH 116 is obtained and stored in the main memory of the PC. Record (step 1605). The sector ID is an identification number uniquely assigned to each sector, which is a fixed-length block that divides the recording area of the hard disk, and is described in the header portion at the head of the sector. Accordingly, in order to obtain the real address on the HDD 24 at the head of the I picture, the sector ID is read from the header of the sector including the head of the I picture, and the number of bytes from the head of this sector to the head of the I picture is offset. You can get as Also, a time stamp indicating the reproduction time of the MPEG2 stream is generated from the PTS (Presentation Time Stmp) included in the payload of the packet 117 and recorded on the main memory of the PC. Thereafter, the acquisition of the video packet 117 is repeated (NO in steps 1606 and 1607). When the video packet including the end position of the I picture is acquired (YES in step 1607), the end position of the I picture is stored on the HDD 24. The real address (sector ID and offset from the head of the sector) is recorded on the main memory of the PC (step 1608).

  If the acquired packet is found to be an audio packet 117 as determined in step 1603, the header 123 of the audio packet 117 is read (step 1609), and the audio packet in the header 123 is read. The audio output mode is acquired from the value of the bit 126 indicating the output mode (stereo / mono) (step 1610).

  As described above, the recording start position and the recording end position, the time stamp, and the audio output mode, which are real address information on the HDD 24 of the I picture in a predetermined reproduction time unit, are obtained, and these information are collected in one structure. And generated as an I picture information file 111. The plurality of I picture information files 111 created on the PC in this way are transferred to the portable HDD video playback device 100 and stored in a reserved area in the buffer memory 95 that can be referred to by the system controller 61.

  Next, the reproduction operation of the MPEG2 stream will be described.

  FIG. 20 is a flowchart showing the procedure of the MPEG2 stream playback process.

  First, the system controller 61 reads information on an MPEG file to be reproduced designated by the user from the RAM 72 (step 2001). In the FAT, a file recorded in the HDD 24 and a real address (cluster number) in which the head of the file is written are managed by a directory entry. Take the first recorded cluster number. Subsequently, based on this cluster number, the system controller 61 creates a reproduction table in which the cluster numbers in which the corresponding MPEG files are written are registered from the FAT table in the order in which they are reproduced (step 2002).

  Subsequently, the system controller 61 reads trick play reproduction information designated by the user from the RAM 72 (step 2003). If trick play playback is designated (YES in step 2004), trick play playback processing is started. When trick play playback is not designated, the system controller 61 calculates a playback table ID at the time of switching the audio output mode based on the contents of the I picture information file 111 held in the buffer memory 95 ( Step 2005). Here, the reproduction table ID is an ID given to each entry of the reproduction table.

  Next, the system controller 61 performs various settings such as hardware necessary for reproducing the MPEG2 stream (step 2006). Thereafter, the cluster number is read from the head of the reproduction table, and the data is read from the corresponding cluster of the HDD 24 and transferred to the buffer memory 95 (step 2007). Then, the information (reproduction table ID) indicating the reading completion position of the reproduction table is updated (step 2008).

  Here, it is determined whether or not the reproduction table ID indicating the read completion position of the reproduction table matches the reproduction table ID calculated based on the I picture information file 111 and when the audio output mode is switched (step). 2009), if they match, the system controller 61 switches the setting of the audio output mode of the portable HDD video playback device 100 (step 2010). That is, the system controller 61 performs control so that the output mode of the D / A converter 101 is switched between stereo and monaural. The D / A converter 101 is a circuit designed to enable only the R channel output when the monaural output mode is set, and to enable the R channel and L channel outputs when the stereo output mode is set. If the playback table IDs do not match, switching of the audio output mode setting of the portable HDD video playback device 100 is skipped.

  Thereafter, the system controller 61 transfers the MPEG2 stream stored in the buffer memory 95 to the MPEG2 decoder 89 (step 2011). Of the output of the MPEG2 decoder 89, the video data is sent to the LCD controller 99, and the LCD controller 99 controls the driving of the LCD 21 to reproduce the video. On the other hand, the audio data output from the MPEG2 decoder 89 is converted into an analog signal by the D / A converter 101. At this time, if monaural is set as the audio output mode, an R channel audio signal is output from the D / A converter 101, and if stereo is set, the R / L channel audio from the D / A converter 101 is output. A signal is output. The audio signal output from the D / A converter 101 is sent to the headphones connected to the headphone terminal 10.

  Subsequently, returning to step 2007, the next cluster number is read from the reproduction table, and thereafter, the above operation is repeated until reading of all entries in the reproduction table is completed (step 2012).

  Next, trick play reproduction processing will be described.

  FIG. 21 is a flowchart showing a flow of the trick play reproduction process.

  First, the system controller 61 sets the MPEG2 decoder 89 to trick play mode (step 2101). As a result, the MPEG2 decoder 89 is set to process only I pictures in the GOP 122 of the MPEG2 video stream 130 shown in FIG.

  Subsequently, the system controller 61 acquires trick play reproduction information designated by the user from the RAM 72 (step 2102). For example, trick play playback information such as fast forward playback and rewind playback at 15 times speed and 60 times speed is acquired. This trick play reproduction information is set in the RAM 72 as needed in accordance with the operation of the reproduction-related key 33 by the user and the operation time. That is, when the position on the right side of the reproduction-related key 33 is pressed once, 15 × trick-play reproduction information is set in the RAM 72 and continues for a certain time (for example, 3 seconds) after the continuous fast-forward reproduction is started. When the button is pressed, trick play reproduction information of 60 × speed is set in the RAM 72.

  Thereafter, the system controller 61 advances the reference position of the reproduction table to the trick play reproduction position based on the acquired trick play reproduction information and the contents of the I picture information file 111 (step 2103). The system controller 61 reads from the I picture information file 111 the actual address on the HDD 24 where the I picture necessary for trick play playback after the trick play playback position is recorded, and reads the data at the corresponding location on the HDD 24. (Step 2104).

  For example, when a video for one second is composed of 30 frames, when performing fast-forward playback or rewind playback at 15 times speed, only two of the 30 frames need be played back. If the I picture information file 111 is generated in units of 0.5 seconds, the system controller 61 acquires the real address of the I picture from all the I picture information files 111 and reads the data from the HDD 24. When fast-forwarding or rewinding reproduction at 60 times speed is performed, the real address of the I picture is acquired from one of the four consecutive I picture information files 111, and the data can be read from the HDD 24. The reading of data from the HDD 24 is based on information on the recording start position and recording end position of the I picture on the HDD 24 registered in the I picture information file 111 in the form of a sector ID and an offset from the head of the sector. Therefore, only I picture data is read from the HDD 24 and transferred to the buffer memory 95.

  The I picture data read from the HDD 24 in this way is transferred to the MPEG2 decoder 89 (step 2105), where it is decoded and output to the LCD controller 99.

  The system controller 61 reads the trick play reproduction information set in the RAM 72 every time transfer of one I picture data from the HDD 24 to the MPEG2 decoder 89 is completed, and the trick play reproduction information and the I picture information file 111 are read. Based on the contents, the reference position of the reproduction table is advanced to the next trick play reproduction position (step 2103). If there is a change in the trick play playback information set in the RAM 72 at this time (for example, switching between 15 × speed and 60 × speed, switching between fast forward playback and rewind playback, etc.) Match the reference position.

  The above processing is repeated until trick play playback is completed up to the end of the playback table. When trick play playback is completed up to the end of the playback table (YES in step 2106), trick play playback ends.

  As described above, in this embodiment, the MPEG2 stream recorded on the HDD 24 of the portable HDD video playback device 100 is analyzed on the PC, and the real address and audio output mode information of the I picture HDD 24 are analyzed. Is created, and the I picture information file 111 is transferred to and held in the portable HDD video playback device 100. On the other hand, in the portable HDD video playback device 100, during trick play playback such as fast forward playback and rewind playback, I picture data is read from the HDD 24 based on the contents of the I picture information file 111, decoded, and trick played. Perform playback. As a result, in order to perform trick play playback with the portable HDD video playback device 100, the system controller 61 analyzes the header in the MPEG2 stream to calculate the location of the I picture, or the packet from the beginning of the video stream. There is no need to count the number, the burden on the system controller 61 is greatly reduced, and smooth fast-forward playback and rewind playback are realized.

  In this embodiment, reading of screen data compressed in a frame can be started from any position in the video stream. In addition, according to this embodiment, since not only the recording start position of the I picture on the hard disk but also the recording end position can be acquired from the I picture information file 111, detection of the end of the in-frame compressed data is awaited in the decoding process. Accordingly, reading of data from the HDD 24 can be terminated, and meaningless reading of data from the HDD 24 does not occur. Thereby, the burden of the system controller 61 can be reduced.

  Also, based on the audio output mode information included in the I picture information file 111, the timing for switching the audio output mode can be calculated in advance, and the contents of the header 123 of the MPEG2 audio stream 140 are reproduced in the portable HDD video playback. The timing for switching the audio output mode can be obtained without analysis by the system controller 61 of the apparatus 100. Thereby, the burden on the system controller 61 when the MPEG2 stream is read from the HDD 24 and the audio is reproduced can be reduced.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  In the above embodiment, the case of reproducing an MPEG2 stream has been described. However, the present invention is not limited to this, and a video stream including intra-frame compressed screen data and inter-frame compressed screen data is not limited thereto. As long as the audio stream and the audio stream are multiplexed, the present invention can be applied to other types of multiplexed streams. In the above embodiment, the HDD is used as the recording medium. However, the present invention can be applied to other types of recording media as long as they are readable / writable and randomly accessible.

  In the above embodiment, the sector ID and the offset information from the head of the sector are used as the recording start position and the recording end position of the intra-frame compressed data such as the I picture. It is also possible to indicate the recording start position and recording end position of the intra-frame compressed data such as the I picture by the offset information.

1 is a perspective view showing an appearance of a portable HDD video playback device according to an embodiment of the present invention. FIG. 2 is a plan view showing the portable HDD video playback device of FIG. 1 from the front. It is sectional drawing of the portable HDD video reproducing apparatus of FIG. It is the top view which looked at the portable HDD video playback apparatus of FIG. 1 from the top. It is the figure which showed the housing | casing 1 in sectional drawing of FIG. It is a figure which shows the structure of the circuit mounted in the main board | substrate. It is a figure which shows the display window of the recording content displayed on PC by the transfer application, and the window for transfer. It is a figure which shows an action menu. It is a figure which shows a title list. It is a figure which shows an environment setting screen. It is a figure which shows the screen which displays the reproduction | regeneration progress (remaining) time of a video stream. It is sectional drawing which shows other embodiment of the portable HDD video playback apparatus of this invention. FIG. 2 is a plan view showing the internal structure of the portable HDD video playback device of FIG. 1 for each layer. It is a figure which shows the process sequence from the power-on of the portable HDD video reproduction apparatus of FIG. 1 to a video reproduction start. It is a figure which shows the structure of an I picture information file. It is a flowchart which shows the preparation procedure of the I picture information file of FIG. It is a block diagram of an MPEG2 system stream. It is a block diagram of an MPEG2 video stream. It is a block diagram of an MPEG2 audio stream. It is a flowchart which shows the procedure of the reproduction process of an MPEG2 stream. It is a flowchart which shows the flow of the process of trick play reproduction | regeneration. It is a figure which shows the structure of the recording area of HDD which employ | adopted the FAT file system. It is a figure which shows the recording position of the file data in the real data area of HDD. It is a figure which shows the example of a FAT management table. It is a figure which shows the example of a reproduction | regeneration table.

Explanation of symbols

24 HDD
61 System controller 72 RAM
89 MPEG2 decoder 95 Buffer memory 100 Portable HDD video playback device 101 D / A converter 111 I picture information file 115 Pack header 116 System header 117 Packet 119 SH
120 MPEG2 system stream 122 GOP
123 Header 130 MPEG2 video stream 140 MPEG2 audio stream

Claims (18)

At least a part of the frame-compressed screen of a recording medium on which data obtained by multiplexing a video stream including an intra-frame compressed screen data and inter-frame compressed screen data and an audio stream is recorded A storage unit for storing an information file including an identifier of a recording unit at a recording start position of the data on the recording medium and an offset from the beginning of the recording unit;
An information recording / reproducing apparatus comprising: a control unit that performs control to read out the frame-compressed screen data from the recording medium based on the information file stored in the storage unit. The information recording / reproducing apparatus according to claim 1, wherein the recording unit identifier of the recording start position of the information file and the offset from the head of the recording unit are a sector ID and an offset from the head of the sector. The information recording / reproducing apparatus according to claim 1, wherein the recording unit identifier of the recording start position of the information file and the offset from the head of the recording unit are a cluster ID and an offset from the head of the cluster. The information recording / reproducing apparatus according to claim 1, further comprising a reproducing unit that decodes the intra-frame compressed screen data read from the recording medium by the control unit and continuously reproduces the decoded screen data. The information file defines mode information that defines whether the audio stream recorded on the recording medium is output in stereo or monaural, and starts recording of the intra-frame compressed screen data on the recording medium It is associated with the position identifier and the offset information from the beginning of the recording unit,
The control unit determines timing for switching the audio output mode based on mode information of the information file when the audio stream is read from the recording medium and the audio is reproduced. The information recording / reproducing apparatus described in 1. The information recording / reproducing apparatus according to claim 1, wherein the intra-frame compressed screen data is an I picture in an MPEG2 stream. At least a part of the frame-compressed screen of a recording medium on which data obtained by multiplexing a video stream including an intra-frame compressed screen data and inter-frame compressed screen data and an audio stream is recorded A storage unit for storing an information file including information of a recording start position and a recording end position of the data on the recording medium;
An information recording / reproducing apparatus comprising: a control unit that performs control to read out the frame-compressed screen data from the recording medium based on the information file stored in the storage unit. The information recording / reproducing apparatus according to claim 7, further comprising a reproducing unit that decodes the intra-frame compressed screen data read from the recording medium by the control unit and continuously reproduces the decoded screen data. The information file defines mode information that defines whether the audio stream recorded on the recording medium is output in stereo or monaural, and starts recording of the intra-frame compressed screen data on the recording medium With the information of the position and the recording end position,
The said control part determines the timing which switches the output mode of the said audio based on the mode information of the said information file, when reading the said audio stream from the said recording medium and reproducing | regenerating an audio. The information recording / reproducing apparatus described in 1. The information recording / reproducing apparatus according to claim 7, wherein the information of the recording start position and the recording end position of the information file is a sector ID and an offset from the head of the sector, respectively. The information recording / reproducing apparatus according to claim 7, wherein the information of the recording start position and the recording end position of the information file is a cluster ID and an offset from the head of the cluster, respectively. 8. The information recording / reproducing apparatus according to claim 7, wherein the intra-frame compressed screen data is an I picture in an MPEG2 stream. A method of playing back a recording medium on which data in which a video stream and an audio stream including screen data compressed within a frame and screen data compressed between frames are multiplexed is recorded,
An information file including an identifier of a recording unit of a recording start position on the recording medium of at least a part of the intra-frame compressed screen data and an offset from the head of the recording unit is stored in the storage unit,
A playback method comprising: reading the screen data compressed in the frame from the recording medium based on the information file stored in the storage unit, decoding and continuously playing back the screen data. The information file stored in the storage unit includes mode information that defines whether the audio stream recorded in the recording medium is output in stereo or monaural, the mode information of the screen data compressed in the frame It is associated with the identifier of the recording unit at the recording start position on the recording medium and the offset information from the beginning of the recording unit,
14. The reproduction method according to claim 13, wherein when reproducing the audio by reading the audio stream from the recording medium, the timing for switching the output mode of the audio is determined based on the mode information of the information file. . A method of playing back a recording medium on which data in which a video stream and an audio stream including screen data compressed within a frame and screen data compressed between frames are multiplexed is recorded,
Storing at least a part of the information file including information on a recording start position and a recording end position on the recording medium of the screen data compressed in the frame;
A playback method comprising: reading the screen data compressed in the frame from the recording medium based on the information file stored in the storage unit, decoding and continuously playing back the screen data. Computer
Transfer means for transferring data obtained by multiplexing a video stream and an audio stream including intra-frame compressed screen data and inter-frame compressed screen data to a recording medium of an externally connected information recording / reproducing apparatus When,
Accessing a recording medium of an information recording / reproducing apparatus connected to the computer, and recording unit of a recording start position on the recording medium of at least a part of the frame-compressed screen data recorded on the recording medium An information file creating means for creating an information file including an identifier and an offset from the beginning of the recording unit;
A program that functions as information file transfer means for transferring the information file created by the information file creation means to the information recording / reproducing apparatus.   The information file creating means sets mode information that defines whether the audio stream recorded on the recording medium of the information recording / reproducing apparatus is output in stereo or monaural, and stores the mode information of the screen data compressed in the frame. The program according to claim 16, wherein the program is described in the information file in association with an identifier of a recording unit at a recording start position on the recording medium and information on an offset from the head of the recording unit. Computer
Transfer means for transferring data obtained by multiplexing a video stream and an audio stream including intra-frame compressed screen data and inter-frame compressed screen data to a recording medium of an externally connected information recording / reproducing apparatus When,
Recording start position and recording end position on the recording medium of at least a part of the frame-compressed screen data recorded on the recording medium by accessing a recording medium of the information recording / reproducing apparatus connected to the computer An information file creating means for creating an information file including the information of
A program that functions as information file transfer means for transferring the information file created by the information file creation means to the information recording / reproducing apparatus.

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