JP2009049474A - Information processing apparatus and re-encoding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information processing apparatus capable of adjusting a bit rate depending on the importance of a scene by using information obtained by indexing, and to provide a re-encoding method. <P>SOLUTION: The information processing apparatus has a structure in which motion picture data are decoded, the decoded motion picture data are subjected to indexing processing by an indexing processing section 60, and the motion picture data are re-encoded on the basis of a result of the indexing processing and a parameter set in advance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for transcoding image information, for example, and more particularly to an information processing apparatus and a re-encoding method that can improve image quality at a location that matches a predetermined condition.

  In recent years, image information has been handled as digital data. At that time, for the purpose of efficient transmission and storage of information, compression is performed by orthogonal transform such as discrete cosine transform and motion prediction / compensation using redundancy unique to image information. An apparatus conforming to a system such as MPEG is widely used.

  Furthermore, the standardization of the H.264 (ITU-T Q6 / 16 VCEG) encoding method was performed with the initial purpose of image encoding for video conferencing. H. H.264 is known to achieve higher encoding efficiency than a conventional encoding method such as MPEG2 or MPEG4, although a larger amount of calculation is required for encoding and decoding.

For example, MPEG-2 format encoded information is converted into H.264 format. When transcoding to H.264 format encoded information, the input stream is temporarily stored in memory in order to suppress degradation in image quality during transcoding, and the transition of image quality over a long period (several minutes) is grasped and reflected in the encoding. A method is disclosed (see, for example, Patent Document 1).
JP 2006-295502 A

  In the technique of this patent document 1, only the encoding parameter is dynamically changed according to the change in the image quality of the input stream, and control according to the video scene cannot be performed.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an information processing apparatus and a re-encoding method capable of adjusting the bit rate according to the importance of a scene.

  In order to achieve the above object, according to one aspect of the present invention, first encoded data obtained by encoding image information using a first encoding scheme is encoded using a second encoding scheme. An information processing apparatus that transcodes into two encoded data, the decoding means for decoding the first encoded data, and one or more indexes assigned to the image information decoded by the decoding means An indexing unit that divides the image into a plurality of scenes, and a code that encodes the image information decoded by the decoding unit with different image quality for each scene divided by the indexing unit and encodes the second encoded data And an information processing apparatus.

  A re-encoding method for transcoding first encoded data obtained by encoding image information using a first encoding method into second encoded data encoded using a second encoding method. A decoding step of decoding the first encoded data, an indexing step of assigning one or more indexes to the image information decoded in the decoding step and dividing the information into a plurality of scenes, and the decoding And a coding step of coding the image information decoded by the coding means with different image quality for each scene divided by the indexing means and coding the second coded data. A method is provided.

  According to the present invention, it is possible to provide an information processing apparatus and a re-encoding method that can adjust the bit rate according to the importance of a scene.

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

  First, the configuration of an information processing apparatus according to an embodiment of the present invention will be described with reference to FIGS. This information processing apparatus is realized as, for example, a notebook personal computer 10.

  FIG. 1 is a perspective view of the notebook personal computer 10 with the display unit opened. The computer 10 includes a computer main body 1 and a display unit 2. The display unit 2 incorporates a display device composed of an LCD (Liquid Crystal Display) 3, and the display screen of the LCD 3 is positioned substantially at the center of the display unit 2.

  The display unit 2 is attached to the computer main body 1 so as to be rotatable between an open position and a closed position. The computer main body 1 has a thin box-shaped housing, and a keyboard 4, a power button 5 for turning on / off the computer 10, an input operation panel 6, a touch pad 7, and the like are arranged on the upper surface. ing.

  The input operation panel 6 is an input device that inputs an event corresponding to a pressed button to the system, and includes a plurality of buttons for starting a plurality of functions. These button groups include a TV start button 6A and a DVD (Digital Versatile Disc) start button 6B. The TV start button 6A is a button for starting a TV function for reproducing and recording broadcast program data such as a digital TV broadcast program. When the TV start button 6A is pressed by the user, the TV function is executed. The TV application program is activated. The DVD activation button 6B is a button for reproducing the video content recorded on the DVD. When pressed by the user, an application program for reproducing the video content is automatically activated.

  Next, the system configuration of the computer 10 will be described with reference to FIG.

  As shown in FIG. 2, the computer 10 includes a CPU 11, a north bridge 12, a main memory 13, a graphics controller 14, a south bridge 15, a BIOS-ROM 16, a hard disk drive (HDD) 17, an optical disk drive (ODD) 18, A digital TV broadcast tuner 19, an embedded controller / keyboard controller IC (EC / KBC) 20, a network controller 21, a sub processor 90, and the like are provided.

  The CPU 11 is a processor provided for controlling the operation of the computer 10, and executes various application programs such as an operating system (OS) and a video playback application program 100 that are loaded from the HDD 17 to the main memory 13. .

  The sub processor 90 is hardware for decoding (decoding), re-encoding and reproducing encoded moving image data. The sub processor 90 is connected to the H.264. This is a hardware decoder corresponding to the H.264 / AVC standard. The secondary processor 90 is connected to the H.264. H.264 / AVC standard encoded video stream (for example, a digital TV broadcast program received by the digital TV broadcast tuner 19 or an HD (High Definition) standard video content read from the ODD 18) ). It also has a function of re-encoding a TV program obtained by decoding. This re-encoding is performed for the purpose of reducing the file capacity by performing a process of reducing the bit rate of a low importance scene such as a CM in a recorded TV program, for example.

  In addition, the sub processor 90 analyzes a moving image such as a TV program obtained by decoding, and performs an indexing process in accordance with, for example, detection of a silent section or detection of a face image. In the indexing process, an index is assigned to the moving image, so that it can be divided into a plurality of scenes. For example, a CM section, a scene where a specific person appears, and the like can be distinguished.

  The CPU 11 also executes a basic input output system (BIOS) stored in the BIOS-ROM 16. The BIOS is a program for hardware control.

  The north bridge 12 is a bridge device that connects the local bus of the CPU 11 and the south bridge 15. The north bridge 12 also includes a memory controller that controls access to the main memory 13. The north bridge 12 also has a function of executing communication with the graphics controller 14 via an AGP (Accelerated Graphics Port) bus or the like.

  The graphics controller 14 is a display controller that controls the LCD 3 used as a display monitor of the computer 10. The graphics controller 14 generates a display signal to be sent to the LCD 3 from the image data written in the video memory (VRAM) 14A.

  The south bridge 15 controls each device on an LPC (Low Pin Count) bus and each device on a PCI (Peripheral Component Interconnect) bus. The south bridge 15 includes an IDE (Integrated Drive Electronics) controller for controlling the HDD 17 and the ODD 18. Further, the south bridge 15 has a function for controlling access to the BIOS-ROM 16 and a function for controlling the digital TV broadcast tuner 19 via the PCI bus.

  The HDD 17 is a storage device that stores various software and data. An optical disk drive (ODD) 18 is a drive unit for driving a storage medium such as a DVD in which video content is stored. The digital TV broadcast tuner 19 is a receiving device for receiving broadcast program data such as a digital TV broadcast program from the outside.

  The EC / KBC 20 is a one-chip microcomputer in which an embedded controller for power management and a keyboard controller for controlling the keyboard (KB) 4 and the touch pad 7 are integrated. The EC / KBC 20 has a function of turning on / off the computer 10 in accordance with the operation of the power button 5 by the user. Further, the EC / KBC 20 can also turn on the computer 10 in accordance with the operation of the TV start button 6A and the DVD start button 6B by the user. The network controller 21 is a communication device that executes communication with an external network such as the Internet.

  FIG. 3 is a functional block diagram of functions of the sub-processor 90 operating on the computer 10 having the above configuration.

  As shown in FIG. 3, the sub processor 90 stores the storage device 50 before Transcode, Readers 51 and 64, Demuxer 52, video Decoder 53, video Encoder 61, audio Decoder 54, audio Encoder 55, scaler 56, Muxer 57, Writer 58 and 65, and storage after Transcode. A device 59, an indexing processing unit 60, an indexing data storage device 66, a post-indexing processing unit 63, and program information 62 such as an EPG are provided.

  The pre-Transcode storage device 50 is an HDD 17 that stores image information such as recorded TV programs. The Reader 51 reads image information such as a recorded TV program from the pre-Transcode storage device 50. The Demuxer 52 separates audio information and video information from the image information. The video decoder 53 and the audio decoder 54 decode video information and audio information, respectively. The audio encoder 55 encodes the decoded audio. The scaler 56 changes the scale of the video information. The Muxer 57 synthesizes the encoded audio information and the video information whose scale has been changed. The indexing processing unit 60 performs indexing processing according to audio information and video information from the audio decoder 54 and the scaler 56, assigns an index to divide it into a plurality of scenes, and determines the importance of each scene. The indexing data storage device 66 is the HDD 17 that stores the indexing data by the writer 65. Program information 62 such as EPG is program guide data received from a site or the like that distributes program information such as EPG. The post-indexing processing unit 63 reads the indexing data from the indexing data storage device 66 by the reader 64 and applies it to the image information. At this time, the program information is also read from the program information 62 such as EPG and applied to the post-indexing process. By this post-indexing process, the image information is subjected to a process of reducing the bit rate of a less important part (scene) such as a CM, and is output to the video encoder 61.

  The level of importance (evaluation value) of the image information is set in advance as parameter information, for example, as shown in FIG. For example, the following settings are made according to the genre of the recorded TV program. The genre of the recorded TV program can be determined based on program guide data such as EPG.

  First, it is assumed that the original image quality of a recorded TV program is, for example, 17 Mbps (first encoded data). This image quality is transcoded to 15 to 8.5 Mbps, which is the second encoded data, according to a predetermined condition.

  For example, CM sets transcode to the lowest image quality at a bit rate of 8.5 Mbps in all programs. If the recorded TV program is a sport such as soccer, for example, voice data such as an announcer is detected, and if a keyword such as “goal” or “free kick” is detected, the evaluation value is 0.8. The bit rate (maximum image quality) is 17 Mbps. Also, the cheer volume is detected, and the evaluation value is set according to the ratio of the cheer volume. For example, the evaluation value is 0.2 to 0.8. As shown in FIG. 4, the bit rate is set to 10, 12, 15, 17 (Mbps) corresponding to the evaluation value.

  Furthermore, if the genre of the recorded TV program is a drama, a favorite performer is registered, and the evaluation value is set to 0 to 0.8 at a ratio of conditions that match the performer. For example, the evaluation value is set based on the number of times that the keyword matches the subtitle keyword, the probability of being a favorite performer, or the like using face recognition. For example, the evaluation value is 0.2 to 0.8. As shown in FIG. 4, the bit rate is set to 10, 12, 15, 17 (Mbps) corresponding to the evaluation value.

  Further, if the genre of the recorded TV program is a song program, a favorite performer or song is registered, and the evaluation value is set to 0 to 0.8 at a ratio of conditions matching the performer or song. For example, the evaluation value is set based on the number of times that the keyword matches the subtitle keyword, the probability of being a favorite performer, or the like using face recognition. Furthermore, an evaluation value can be set according to the probability of being a registered song according to the degree of coincidence of the melody. For example, the evaluation value is 0.2 to 0.8. As shown in FIG. 4, the bit rate is set to 10, 12, 15, 17 (Mbps) corresponding to the evaluation value.

  Next, the processing procedure of the sub processor 90 will be described with reference to the flowchart of FIG.

  The pre-Transcode storage device 50 reads out image information such as a recorded TV program and starts reproduction of moving image data (step S101). The sub processor 90 determines whether or not the setting of the TV application program is an image quality-oriented setting (step S102). If the setting of the TV application program is an image quality-oriented setting, the sub processor 90 performs processing according to the image quality setting. That is, the moving image data is stored with the highest image quality without transcoding.

  On the other hand, when the setting of the TV application program is not the image quality priority setting (NO in step S102), the sub processor 90 performs the indexing process of the moving image data. In this indexing process, voice detection of video data, caption detection, cheer detection, face recognition, CM detection, and the like are performed and stored as indexing data in the indexing data storage device 66 (step S103).

  The post-indexing processing unit 63 of the sub processor 90 reads the indexing data from the indexing data storage device 66, and also reads the program information from the program information 62 such as EPG (step S104), and performs post-indexing processing (step S105). By this post-indexing process, the image information is subjected to a process of lowering the bit rate of a less important part (scene) such as a CM. It is output to the video Encoder 61.

  As described above, according to the present embodiment, the bit rate can be adjusted according to the importance of the scene using information obtained by indexing or the like. For this reason, since the bit rate can be lowered in a less important scene, the file size of recorded program data can be suppressed.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The perspective view showing the appearance of the computer concerning one embodiment of the present invention. The figure which shows the system configuration | structure of the computer of the embodiment. The functional block diagram of the function which the subprocessor used with the computer of the embodiment has. The schematic diagram which shows the various parameters used for an indexing process. The flowchart which shows the procedure of the process of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Computer main body, 2 ... Display unit, 3 ... LCD, 4 ... Keyboard, 5 ... Power button, 6 ... Input operation panel, 6A ... TV start button, 6B ... DVD start button, 7 ... Touchpad, 10 ... Computer, DESCRIPTION OF SYMBOLS 11 ... CPU, 12 ... North bridge, 13 ... Main memory, 14 ... Graphics controller, 14A ... Video memory, 15 ... South bridge, 16 ... BIOS-ROM, 17 ... Hard disk drive (HDD), 18 ... Optical disk drive (ODD) , 19 ... Digital TV broadcast tuner, 20 ... Embedded controller / keyboard controller IC (EC / KBC), 21 ... Network controller, 50 ... Storage device before Transcode, 51, 64 ... Reader, 52 ... Demuxer, 53 ... Video decoder, 61 ... Video Encoder, 54 ... Audio D ecoder, 55 ... audio encoder, 56 ... scaler, 57 ... muxer, 58, 65 ... writer, 59 ... storage device after transcoding, 60 ... indexing processing unit, 62 ... program information such as EPG, 63 ... post-indexing processing unit, 66 ... Indexing data storage device, 90 ... Sub processor, 100 ... Video playback application program, 110 ... Decoding processing unit, 111 ... Slice header processing unit, 112 ... Slice data processing unit, 112A ... Macroblock parsing processing unit, 120 DESCRIPTION OF SYMBOLS ... Signal processing part 121 ... Signal processing control part 122 ... Macroblock signal processing part 123 ... Deblock processing part 201 ... Inverse quantization part 202 ... Inverse DCT part 203 ... Adder part 204 ... Mode change switch , 205 ... Intra prediction unit, 206 ... Weighted prediction unit, 207 ... Motion vector prediction , 208 ... interpolation prediction unit.

Claims (8)

An information processing apparatus that transcodes first encoded data obtained by encoding image information using a first encoding method into second encoded data encoded using a second encoding method,
Decoding means for decoding the first encoded data;
Indexing means for assigning one or more indexes to the image information decoded by the decoding means and dividing the image information into a plurality of scenes;
Encoding means for encoding the image information decoded by the decoding means with different image quality for each scene divided by the indexing means and encoding the second encoded data;
An information processing apparatus comprising:   The information processing apparatus according to claim 1, wherein the indexing unit assigns an index based on genre information associated with the image information.   The information processing apparatus according to claim 1, wherein the encoding unit sets a bit rate for each scene.   The encoding means determines the image quality of each scene based on one or more information of a keyword based on speech recognition, a keyword based on subtitle detection, CM detection, cheer detection, and matching based on face recognition. The information processing apparatus according to claim 1. A re-encoding method for transcoding first encoded data in which image information is encoded by a first encoding method into second encoded data encoded by a second encoding method,
A decoding step of decoding the first encoded data;
An indexing step of assigning one or more indexes to the image information decoded in the decoding step and dividing the image information into a plurality of scenes;
An encoding step of encoding the image information decoded by the decoding unit with different image quality for each scene divided by the indexing unit and encoding the second encoded data;
A re-encoding method comprising:   6. The re-encoding method according to claim 5, wherein, in the indexing step, an index is assigned based on genre information associated with the image information.   6. The re-encoding method according to claim 5, wherein a bit rate is set for each scene in the encoding step.   In the encoding step, the image quality of each scene is determined based on one or more information of a keyword based on speech recognition, a keyword based on subtitle detection, CM detection, cheer detection, and matching based on face recognition. The re-encoding method according to claim 5.

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