JP2017076908A - Content reproduction device, content reproduction method, and content reproduction program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a delay in reproduction of a content.SOLUTION: A content reproduction device acquires data from an external device, reproduces, from the data acquired from the external device, a content in data having completed processing on reproduction of the content, determines whether a delay has occurred in the processing on the data acquired from the external device, and controls synchronization processing on data to be acquired subsequently to the acquired data according to a result of the determination as to whether the delay has occurred.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a content reproduction apparatus, a content reproduction method, and a content reproduction program.

  In recent years, a plurality of content reproduction apparatuses are connected, and content data such as video and audio reproduced on the predetermined content reproduction apparatus is distributed to the other content reproduction apparatuses, thereby reproducing on the predetermined content reproduction apparatus. There is known a content playback system that plays back the content being played on other content playback devices (see, for example, Patent Document 1).

  In such a content reproduction system, the content data reproduced by the predetermined content reproduction device is transmitted to the other content reproduction device, and the content reproduction device receiving the data reproduces the content based on the data. It is supposed to be.

  However, in such a content reproduction system, data processing such as encoding processing of data to be transmitted and decoding processing of received data is required on the transmission side and reception side, respectively. The content is reproduced later than the transmission side.

  In such a content playback system, if the playback delay of the content on the receiving side is small, there is no problem because the viewer cannot recognize the playback delay, but if it is large, the viewer will reduce the playback delay. As a result, it becomes possible to recognize the problem, and the usability deteriorates.

  The present invention has been made to solve such a problem, and an object thereof is to reduce the reproduction delay of content.

  In order to solve the above-described problem, an aspect of the present invention provides a data acquisition unit that acquires data from an external device, and data that has been processed for content reproduction among the data acquired from the external device A content playback unit that plays back content, a delay occurrence determination unit that determines whether or not a delay has occurred in the processing for the data acquired from the external device, and whether or not the delay has occurred A synchronization control unit that controls a synchronization process for data acquired after the acquired data according to the determination result.

  According to the present invention, it is possible to reduce content reproduction delay.

It is a figure which shows the operation | use form of the video display system which concerns on embodiment of this invention. It is a block diagram which shows typically the hardware constitutions of the projector which concerns on embodiment of this invention. It is a block diagram which shows typically the function structure of the projector and client terminal which concern on embodiment of this invention. It is a figure showing typically the structure of the cue concerning the embodiment of the present invention. It is a sequence diagram of a video display process in a video display system according to an embodiment of the present invention. It is a sequence diagram of a video display process in a video display system according to an embodiment of the present invention. It is a sequence diagram of the video display process in the conventional video display system. It is a sequence diagram of a video display process in a video display system according to an embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention. 6 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the embodiment of the present invention.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a plurality of content reproduction devices are connected, and the predetermined content reproduction is performed by distributing content data such as video and audio reproduced on the predetermined content reproduction device to other content reproduction devices. A content playback system for playing back content being played back on the device also on other content playback devices will be described.

  In particular, in the present embodiment, as an example of a content reproduction system, a video display device and an information processing device are connected, and content data such as video and audio reproduced by the information processing device is transmitted to the video display device. A video display system that causes the video display device to also play back the content being played back by the information processing device will be described.

  In such a video display system, in order to prevent the video and audio from being reproduced with a shift on the receiving side, the transmitting side adds information describing the playback time to the video data and audio data. The transmission and reception side waits until the playback time (hereinafter referred to as “synchronization processing”), and then starts playback of video and audio.

  In the video display system configured as described above, time is required for data processing such as encoding processing of data to be transmitted and decoding processing of received data on the transmitting side and the receiving side, respectively, and time is also required for data transmission. Therefore, on the receiving side, video / audio is played back later than the transmitting side.

  In such a video display system, if the playback delay of video / audio on the receiving side is small, there is no problem because the viewer cannot recognize the playback delay. The delay can be recognized, which causes problems such as reduced usability.

  Therefore, in the video display system according to the present embodiment, when the video / audio playback delay becomes longer than a predetermined time, the video display device performs the following processing until the playback delay reaches the predetermined time, that is, The synchronization process is not performed until the reproduction delay is eliminated. In the video display system according to the present embodiment, the video display device is configured as described above, so that reproduction delay can be reduced.

  First, an operation mode of the video display system according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an operation mode of the video display system according to the present embodiment.

  As shown in FIG. 1, the video display system according to the present embodiment is configured by connecting a projector 1 and a client terminal 2 so as to communicate with each other via a network 3.

  The projector 1 modulates a light beam emitted from a light source in accordance with an input video signal to form an optical image, and enlarges and displays the formed projection image on a projection surface such as a wall or a screen. It is a video display device that plays back video. Further, the projector 1 reproduces sound by outputting sound from a speaker in accordance with the input sound signal.

  In the present embodiment, the projector 1 reproduces the video / audio according to the video / audio data transmitted from the client terminal 2, thereby obtaining the same video / audio as the video / audio reproduced by the client terminal 2. Reproduce.

  The client terminal 2 is an information processing terminal operated by a user, and is realized by an information processing apparatus such as a PC (Personal Computer), a PDA (Personal Digital Assistant), a smartphone, and a tablet terminal. That is, in this embodiment, the client terminal 2 functions as an external device.

  The network 3 includes, for example, LAN (Local Area Network), Ethernet (registered trademark), USB (Universal Serial Bus), Bluetooth (registered trademark), Wi-Fi (Wireless Fidelity) (registered trademark), FeliCa (registered trademark), Interface using PCIe (Peripheral Component Interconnect Express), VGA (Video Graphics Array), DVI (Digital Visual Interface), IEEE (The Institute of Electrical and other standards).

  In the video display system configured as described above, the projector 1 according to the present embodiment, when the video / audio playback delay becomes longer than the predetermined time, the playback delay becomes the predetermined time in the subsequent processing. In other words, the synchronization processing is not performed until the reproduction delay is eliminated. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that the reproduction delay can be reduced by the amount of the synchronization time.

  Next, the hardware configuration of the projector 1 and the client terminal 2 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram schematically showing a hardware configuration of the projector 1 according to the present embodiment. In FIG. 2, the hardware configuration of the projector 1 is shown as an example, but the same applies to the client terminal 2.

  As shown in FIG. 2, the projector 1 according to this embodiment includes a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 20, a ROM (Read Only Memory) 30, an HDD (Hard Disk Drive) 40, and an output device. 50, an input device 60, and a communication I / F 70 are connected via a bus 80.

  The CPU 10 is an arithmetic device and controls the overall operation of the projector 1. The RAM 20 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 10 processes information. The ROM 30 is a read-only nonvolatile storage medium and stores a program such as firmware.

  The HDD 40 is a nonvolatile storage medium that can read and write information, and stores various data, various programs such as an OS (Operating System), a control program such as a content reproduction program, and an application program.

  The output device 50 is an output interface for displaying video and outputting sound, and modulates a light beam emitted from a display device such as an LCD (Liquid Crystal Display) or LED (Light Emitting Diode), or a light source. Thus, an optical image is formed, and the formed projection image is enlarged and projected on a projection surface such as a wall or a screen, and is realized by an output device such as a speaker, a headphone, or an earphone.

  The input device 60 is a user interface for inputting information to the projector 1 and is realized by an input device such as a keyboard, a mouse, an input button, or a touch panel.

  The communication I / F 70 is an interface for the projector 1 to communicate with other devices, and is Ethernet (registered trademark), USB, Bluetooth (registered trademark), Wi-Fi (registered trademark), FeliCa (registered trademark), PCIe. An interface such as the IEEE standard is used.

  In such a hardware configuration, a program stored in a storage medium such as the ROM 30 or the HDD 40 is read into the RAM 20, and the CPU 10 performs an operation according to the program loaded in the RAM 20, thereby configuring a software control unit.

  A functional block for realizing the functions of the projector 1 and the client terminal 2 according to the present embodiment is configured by a combination of the software control unit configured in this way and hardware.

  Next, functional configurations of the projector 1 and the client terminal 2 according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram schematically showing functional configurations of the projector 1 and the client terminal 2 according to the present embodiment.

  As shown in FIG. 3, the projector 1 according to this embodiment includes a main control unit 101, a reception unit 102, a queue 103, a decoder 104, a synchronization control unit 105, a projection control unit 106, a projection unit 107, and an audio output control unit 108. , An audio output unit 109, an elapsed time measurement unit 110, a difference time calculation unit 111, an accumulated time calculation unit 112, an accumulated time storage unit 113, a frame number counting unit 114, and a CPU usage rate measurement unit 115.

  As illustrated in FIG. 3, the client terminal 2 according to the present embodiment includes a main control unit 201, a display control unit 202, a display unit 203, an audio output control unit 204, an audio output unit 205, a capture unit 206, and an encoder 207. The transmitter 208 is provided.

  The main control unit 201 plays a role of controlling each unit included in the client terminal 2 and gives a command to each unit of the client terminal 2.

  The display control unit 202 displays a screen on the display unit 203 under the control of the main control unit 201. The display unit 203 is an interface that displays a screen. The display unit 203 is realized by the output device 50 illustrated in FIG.

  The audio output control unit 204 causes the audio output unit 205 to output audio in accordance with the control of the main control unit 201. The audio output unit 205 is an output interface that outputs audio. The audio output unit 205 is realized by the output device 50 shown in FIG.

  The capture unit 206 captures the video displayed on the display unit 203 as video data and captures the audio output from the audio output unit 205 as audio data according to the control of the main control unit 201.

  The encoder 207 encodes video data and audio data captured by the capture unit 206. The transmission unit 208 adds header information to the data encoded by the encoder 207 to create a frame that is a data processing unit, packets the created frame for network transmission, and transmits the frame through the network 3 to the projector 1. Send to.

  The main control unit 101 plays a role of controlling each unit included in the projector 1 and gives a command to each unit of the projector 1.

  The receiving unit 102 receives the packets transmitted from the client terminal 2 one frame at a time, constructs a frame from the received packet, and stores (enqueues) the frame in the queue 103. When the reception unit 102 stores the frame in the queue, the reception unit 102 immediately shifts to reception waiting for the next packet without waiting for decoding processing by the decoder 104. In the present embodiment, the receiving unit 102 functions as a data acquisition unit.

  The queue 103 temporarily stores the frames stored by the receiving unit 102. In the present embodiment, the queue 103 functions as a data storage unit. The decoder 104 sequentially reads (dequeues) the frames stored in the queue 103 one frame at a time, and decodes the data portion of the frames from the header information of the read frames.

  Here, the structure of the queue 103 according to the present embodiment will be described with reference to FIG. FIG. 4 is a diagram schematically illustrating the structure of the queue 103 according to the present embodiment. As shown in FIG. 4, the queue 103 according to the present embodiment has a first-in first-out structure, and the decoder 104 reads out the frame stored first by the receiving unit 102.

  The synchronization control unit 105 controls the synchronization process in order to match the reproduction timing of video and audio based on the data decoded by the decoder 104.

  The projection control unit 106 projects and displays an image on the projection unit 107 based on the data decoded by the decoder 104 under the control of the main control unit 101. The projection unit 107 is an output interface that projects and displays an image on a projection surface such as a wall or a screen. The projection unit 107 is realized by the output device 50 illustrated in FIG.

  The audio output control unit 108 causes the audio output unit 109 to output audio based on the data decoded by the decoder 104 under the control of the main control unit 101. The audio output unit 109 is an output interface that outputs audio. The audio output unit 109 is realized by the output device 50 shown in FIG. In the present embodiment, the projection control unit 106 and the audio output control unit 108 function as a content reproduction unit.

  The elapsed time measurement unit 110 measures an elapsed time P (ms) from the start of a specific process for a certain frame to the start of the same process for the next frame for each frame.

  For example, the elapsed time measuring unit 110 measures the elapsed time P (ms) from the start of the synchronization process for a certain frame to the start of the synchronization process for the next frame for each frame. Further, for example, the elapsed time measuring unit 110 measures the elapsed time P (ms) from the start of the packet reception process by the reception unit 102 to the start of the next packet reception process for each frame.

  The difference time calculation unit 111 includes a measurement time P (ms) by the elapsed time measurement unit 110 and a series of processes (for example, a series of processes from the start of the synchronization process to the start of the next synchronization process). ) To calculate the difference from the theoretical value T (ms) of the time required.

  For example, the difference time calculation unit 111 calculates the difference between the elapsed time P (ms) from the start of the synchronization process for a certain frame to the start of the synchronization process for the next frame and the theoretical value T (ms) required for the series of processes. Is calculated for each frame. Further, for example, the differential time calculation unit 111 calculates the elapsed time P (ms) from the start of the reception process of a certain packet to the start of the reception process of the next packet and the theoretical value T (ms) of the time required for the series of processes. The difference is calculated for each frame.

  Specifically, when the client terminal 2 transmits a packet for N frames per second to the projector 1, the projector 1 does not perform the above-described series of processing in N (fps) (frame per second). That is, if it is not performed every 1 / N (second) per frame, a reproduction delay occurs. This 1 / N (second) is the theoretical value T (ms).

  The accumulated time calculation unit 112 calculates the accumulated time R (ms) so far of the difference time PT (ms) calculated by the difference time calculation unit 111. The cumulative time storage unit 113 stores the cumulative time R (ms) calculated by the cumulative time calculation unit 112.

  The frame number counting unit 114 counts the number of frames stored in the queue 103. The CPU usage rate measuring unit 115 measures the usage rate of the CPU 10. In this embodiment, the CPU usage rate measurement unit 115 functions as a usage rate measurement unit.

  Next, video display processing in the video display system according to the present embodiment will be described with reference to FIG. FIG. 5 is a sequence diagram of video display processing in the video display system according to the present embodiment.

  As shown in FIG. 5, first, in the client terminal 2, the capture unit 206 captures video displayed on the display unit 203 as video data and captures audio output from the audio output unit 205 as audio data. (S501). Hereinafter, in the drawings, the capture process in S501 is described as “A”.

  In the client terminal 2, the encoder 207 encodes the video data and audio data captured by the capture unit 206 (S502). Hereinafter, in the drawings, the encoding process in S502 is described as “B”.

  In the client terminal 2, the transmitting unit 208 adds header information to the data encoded by the encoder 207 to create a frame that is a data processing unit, and packets the created frame for network transmission. It transmits to the projector 1 via the network 3 (S503). Hereinafter, in the drawings, the transmission processing in S503 is described as “C”.

  In the projector 1, the receiving unit 102 receives the packets transmitted from the client terminal 2 one frame at a time by data transmission through the network 3 (S 504) (S 505), and composes a frame from the received packets. Then, it is stored (enqueued) in the queue 103 (S506). Hereinafter, in the drawings, the data transmission process in S504 is described as “D”, the reception process in S505 is described as “E”, and the enqueue process in S506 is described as “F”.

  In the projector 1, the decoder 104 sequentially reads out (dequeues) the frames stored in the queue 103 one frame at a time (S 507), and waits until the specified time under the control of the synchronization control unit 105, that is, the video. After synchronizing with the voice (S508), the data portion of the frame is decoded from the header information of the read frame (S509). Hereinafter, in the drawings, the dequeue process in S507 is described as “G”, the synchronization process in S508 is described as “H”, and the decode process in S509 is described as “I”.

  Then, in the projector 1, the projection control unit 106 and the audio output control unit 108 project and display the video on the projection unit 107 based on the data decoded by the decoder 104, and output the audio to the audio output unit 109 (S510). ). Hereinafter, in the drawings, the decoding process in S510 is described as “J”.

  The video display system according to the present embodiment causes the projector 1 to reproduce the same video and audio as the video and audio reproduced by the client terminal 2 by repeatedly performing a series of processes in S501 to S510. Yes.

  The time from the start of the capture process in S501 to the start of the playback process in S510 is a playback delay. As described above, in the video display system according to the present embodiment, the projector 1 reproduces video and audio later than the client terminal 2.

  In such a video display system, if the playback delay of the video and audio on the receiving side is small, there is no problem because the viewer cannot recognize the playback delay. The delay can be recognized, which causes problems such as reduced usability.

  Therefore, in the video display system according to the present embodiment, when the playback delay of the video and audio becomes longer than the predetermined time, the projector 1 performs the subsequent processing until the playback delay reaches the predetermined time. The synchronization processing is not performed until the reproduction delay is eliminated. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  Next, a method for reducing reproduction delay in the video display system according to the present embodiment will be described with reference to FIGS. 6 and 8 are sequence diagrams of video display processing in the video display system according to the present embodiment. FIG. 7 is a sequence diagram of video display processing in a conventional video display system.

  In the following, in the drawings, the suffix attached to each process is identification information for identifying a frame to be processed. In other words, processing with the same subscript indicates processing for the same frame.

  As shown in FIG. 6, in the video display system according to the present embodiment, when each process is executed without delay, the video and audio are theoretically reproduced every T (ms), that is, one frame. A series of processing from S501 to S510 is performed at a winning T (ms).

  Specifically, when the client terminal 2 transmits a packet of N frames per second to the projector 1, the projector 1 theoretically executes the above series of processes when each process is executed without delay. Is performed at N (fps) (frame per second), that is, every 1 / N (second) per frame. In FIG. 7, this 1 / N (second) is described as a theoretical value T (ms).

  However, when a processing delay occurs in at least one of the processing for a certain frame, the processing after that processing is executed with a delay corresponding to the delay, and the time when video and audio are originally reproduced Even if it becomes, it will not be reproduced and a reproduction delay will occur.

  For example, as shown in FIG. 7, when a processing delay L (ms) occurs in the decoding process for the frame with the identifier “0”, the subsequent processing is delayed by the delay L (ms). In other words, the video and audio are not reproduced at the time when the video and audio are reproduced, and a reproduction delay occurs.

  Therefore, as shown in FIG. 8, in the video display system according to the present embodiment, when the playback delay of video and audio becomes longer than the predetermined time T (ms), the projector 1 plays back in the subsequent processing. The synchronization processing is not performed until the delay reaches a predetermined time T (ms), that is, until the reproduction delay is eliminated. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  In FIG. 8, the synchronization time in the synchronization processing is S (ms), and the delay L (ms) in the decoding processing is twice the synchronization time S (ms), that is, L (ms) = Although described as 2S (ms), this is not restrictive.

  Next, a method for reducing reproduction delay in the video display system according to the present embodiment will be described with reference to FIG. FIG. 9 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the present embodiment.

  As shown in FIG. 9, first, the main control unit 101 determines whether or not a frame is stored in the queue 103 (S901).

  If the main control unit 101 determines in the determination process in S901 that no frame is stored in the queue 103 (S901 / NO), the main control unit 101 clears the accumulated time stored in the accumulated time storage unit 113 (S902). ).

  On the other hand, if the main control unit 101 determines in the determination process in S901 that a frame is stored in the queue 103 (S901 / YES), the main control unit 101 stores the accumulated time at the start timing of the synchronization process for that frame (S903). It is determined whether the accumulated time R (ms) stored in the unit 113 is greater than 0 (ms) or 0 (ms) (S904). That is, here, the main control unit 101 functions as a delay occurrence determination unit.

If the main control unit 101 determines that the accumulated time R (ms) is 0 (ms) in the determination process in S904 (S904 / NO), the main control unit 101 causes the elapsed time measurement unit 110 to pass the elapsed time from the start of the synchronization process. The measurement of P ₁ (ms) is started (S905), and each unit is controlled to execute all the processes from the reception process (E) to the reproduction process (F) on the current processing target frame (S905). S906).

  Then, the main control unit 101 determines whether or not more frames are stored in the queue 103 (S907).

  When the main control unit 101 determines in the determination process in S907 that no frame is stored in the queue 103 (S907 / NO), the main control unit 101 clears the accumulated time stored in the accumulated time storage unit 113 (S902). ).

On the other hand, when the main control unit 101 determines in the determination process in S907 that a frame is stored in the queue 103 (S907 / YES), when the synchronization process start timing for the frame comes (S908), the measurement is performed in S905. It is determined whether the elapsed time P ₁ (ms) at which the process is started is longer than or equal to the theoretical value T (ms) of the elapsed time when each process is executed without delay (S909).

When the main control unit 101 determines in the determination process in S909 that P ₁ = T (S909 / YES), the main control unit 101 performs the same process as the process after S906.

On the other hand, when the main control unit 101 determines in the determination process in S909 that P ₁ > T (S909 / NO), the main control unit 101 causes the difference time calculation unit 111 to exceed the excess time P ₁ − that is the difference between P ₁ and T. T is calculated (S910).

Then, the main control unit 101 causes the accumulated time calculating unit 112 to add the excess time P ₁ -T (ms) calculated in S910 to the accumulated time R (ms) stored in the accumulated time storage unit 113 ( S911), it is determined whether or not the accumulated time R (ms) after adding the excess time P ₁ -T (ms) is equal to or greater than the synchronization time S (ms) (S912).

When the main control unit 101 determines that S ≦ R in the determination process in S912 (S912 / YES), the main control unit 101 measures the elapsed time P ₂ (ms) from the start of the synchronization process to the elapsed time measurement unit 110. Start (S913), processing other than the synchronization processing for the current processing target frame, that is, reception processing (E), enqueue processing (F), dequeue processing (G), decoding processing (I), Each unit is controlled to execute only the reproduction process (J) (S914).

  Thus, in the video display system according to the present embodiment, the projector 1 has a video and audio reproduction delay longer than the predetermined time T (ms), and the excess time R (ms) is equal to the normal synchronization time S ( ms) or more (S ≦ R), in the subsequent processing, the synchronization processing is not performed until the reproduction delay reaches a predetermined time T (ms), that is, until the reproduction delay is eliminated. . In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  Then, the main control unit 101 determines whether or not more frames are stored in the queue 103 (S915).

  When the main control unit 101 determines in the determination process in S915 that no frame is stored in the queue 103 (S915 / NO), the main control unit 101 clears the accumulated time stored in the accumulated time storage unit 113 (S902). ).

On the other hand, when the main control unit 101 determines in the determination process in S915 that a frame is stored in the queue 103 (S915 / YES), when the synchronization process start timing for the frame comes (S916), a difference time calculation is performed. to calculate the shortened time _{T-P 2} is the difference between _{P 2} and T in section 111 (S917).

Then, the main control unit 101 causes the cumulative time calculation unit 112 to subtract the shortened time TP ₂ (ms) calculated in S917 from the cumulative time R (ms) stored in the cumulative time storage unit 113 ( S918), processing similar to the processing after S904 is performed.

On the other hand, if the main control unit 101 determines that S> R in the determination process in S912 (S912 / NO), the main control unit 101 measures the elapsed time P ₂ (ms) from the start of the synchronization process to the elapsed time measurement unit 110. Start (S919), and reduce the synchronization time to R (ms) for the current processing target frame and execute all the processes from the reception process (E) to the reproduction process (F). Control (S920).

  Thus, in the video display system according to the present embodiment, the projector 1 has a video and audio reproduction delay longer than the predetermined time T (ms), but the excess time R (ms) is the normal synchronization time S. If it is shorter than (ms) (S> R), in the subsequent processing, only the excess time R (ms) until the reproduction delay reaches a predetermined time T (ms), that is, until the reproduction delay is eliminated. It is configured to reduce the synchronization time. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  Further, when determining that the accumulated time R (ms) is greater than 0 (ms) in the determination process in S904 (S904 / YES), the main control unit 101 performs the same process as the process after S912.

  In FIG. 9, the projector 1 configured to execute processing other than the synchronization processing (S914) when it is determined that S ≦ R in the determination processing in S912 (S912 / YES) has been described. .

  As described above, in the video display system according to the present embodiment, the projector 1 has a video and audio reproduction delay longer than the predetermined time T (ms), and the excess time R (ms) is normal synchronization. When the time is equal to or longer than time S (ms) (S ≦ R), in the subsequent processing, the synchronization processing is not performed until the reproduction delay reaches a predetermined time T (ms), that is, until the reproduction delay is eliminated. Has been. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  In the video display system according to this embodiment, the projector 1 has a video and audio reproduction delay longer than the predetermined time T (ms), but the excess time R (ms) is equal to the normal synchronization time S (ms ) (S> R), in the subsequent processing, until the reproduction delay reaches a predetermined time T (ms), that is, until the reproduction delay is eliminated, the synchronization time is equal to the excess time R (ms). Is configured to shorten. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

Embodiment 2. FIG.
In the first embodiment, when the video and audio playback delay is longer than the predetermined time T (ms), the subsequent processing is performed until the playback delay reaches the predetermined time T (ms). The projector 1 configured so as not to perform the synchronization process until the delay is eliminated has been described. In the video display system according to the first embodiment, the projector 1 is configured in this manner, so that it is possible to reduce the reproduction delay.

  However, the occurrence of a reproduction delay means that a reproduction delay may occur due to a high processing load on the CPU 10 in the projector 1. Therefore, when the projector 1 does not perform the synchronization process and performs other processes in succession, the processing load on the CPU 10 may increase further, or the processing load on the CPU 10 may not decrease at all. There is.

  Therefore, in the present embodiment, when the reproduction delay of video and audio becomes longer than the predetermined time T (ms), in the subsequent processing, until the reproduction delay reaches the predetermined time T (ms), that is, The projector 1 configured to shorten the synchronization time until the reproduction delay is eliminated will be described.

  In the video display system according to the present embodiment, the projector 1 is configured as described above, so that even when the processing load on the CPU 10 is high, it is possible to reduce the reproduction delay without difficulty.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, it shall show the same or an equivalent part, and abbreviate | omits detailed description.

  First, a method for reducing reproduction delay in the video display system according to the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart for explaining a reproduction delay reduction method in the video display system according to the present embodiment. In FIG. 10, only the parts different from FIG. 9 will be described.

  As shown in FIG. 10, in the video display system according to the present embodiment, when the main control unit 101 determines that X ≦ R in the determination process in S1012 corresponding to S912 (S1012 / YES), Each unit is controlled to execute the entire processing from reception processing (E) to reproduction processing (F) by shortening the synchronization time by a fixed time X (ms) with respect to the frame to be processed (S1020).

  As described above, in the video display system according to the present embodiment, when the playback delay of video and audio becomes longer than the predetermined time T (ms), the projector 1 performs the playback delay for the predetermined time in the subsequent processing. The synchronization time is shortened by a fixed time until T (ms), that is, until the reproduction delay is eliminated. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that even when the processing load on the CPU 10 is high, the reproduction delay can be reduced without difficulty.

Embodiment 3 FIG.
In the first and second embodiments, as a condition for determining that the synchronization processing is not performed, or as a condition for determining that the synchronization time is shortened by a fixed time, the video and audio reproduction delay is a predetermined time T. The projector 1 that is assumed to be longer than (ms) has been described.

  On the other hand, in the present embodiment, the number of frames stored in the queue 103 is a predetermined number as a condition for determining that the synchronization processing is not performed or as a condition for determining that the synchronization time is shortened by a fixed time. The projector 1 that is assumed to be larger will be described.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, it shall show the same or an equivalent part, and abbreviate | omits detailed description.

  First, a method for reducing reproduction delay in the video display system according to the present embodiment will be described with reference to FIGS. FIG. 11 and FIG. 12 are flowcharts for explaining a method for reducing reproduction delay in the video display system according to the present embodiment.

  As shown in FIG. 11, first, the main control unit 101 determines whether or not a frame is stored in the queue 103 (S1101).

  If the main control unit 101 determines in the determination process in S1101 that no frame is stored in the queue 103 (S1101 / NO), the main control unit 101 ends the process.

  On the other hand, when the main control unit 101 determines in the determination processing in S1101 that a frame is stored in the queue 103 (S1101 / YES), the main control unit 101 counts the number of frames when the synchronization processing start timing for the frame comes (S1102). The unit 114 counts the number of frames stored in the queue 103 (S1103), and determines whether or not the number of frames counted in S1103 is equal to or less than a predetermined number (S1104).

  When the main control unit 101 determines in the determination process in S1104 that the number of frames stored in the queue 103 is equal to or less than the predetermined number (S1104 / YES), the main control unit 101 receives the received frame for the current process. Each unit is controlled to execute all the processes from the process (E) to the reproduction process (F) (S1105). Then, when the processing for the current processing target frame is completed, the main control unit 101 performs the same processing as the processing after S1101.

  On the other hand, if the main control unit 101 determines in the determination process in S1104 that the number of frames stored in the queue 103 is larger than the predetermined number (S1104 / NO), the main control unit 101 determines that the current processing target frame Each unit is controlled to execute only processing other than the synchronization processing, that is, reception processing (E), enqueue processing (F), dequeue processing (G), decoding processing (I), and reproduction processing (J) (S1106). ). Then, when the processing for the current processing target frame is completed, the main control unit 101 performs the same processing as the processing after S1101.

  As another example, as illustrated in FIG. 12, the main control unit 101 determines that the number of frames stored in the queue 103 is greater than a predetermined number in the determination process in S1203 corresponding to S1103. (S1204 / NO), the synchronization time is shortened by a fixed time X (ms) with respect to the frame to be processed this time, and all processes from the reception process (E) to the reproduction process (F) are executed. Each part is controlled (S1206).

  As described above, in the video display system according to the present embodiment, when the number of frames stored in the queue 103 exceeds the predetermined number, the projector 1 uses the frames stored in the queue 103 in subsequent processing. The synchronization processing is not performed until the number becomes equal to or smaller than the predetermined number, that is, until the reproduction delay is eliminated, or the synchronization time is shortened by a fixed time. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that reproduction delay can be reduced.

  In this embodiment, the number of frames stored in the queue 103 is a predetermined number as a condition for determining that the synchronization processing is not performed or as a condition for determining that the synchronization time is shortened by a fixed time. The projector 1 that is assumed to be larger has been described.

  In addition, in the video display system according to the present embodiment, the projector 1 enters the queue 103 as a condition for determining that the synchronization processing is not performed or as a condition for determining that the synchronization time is shortened by a fixed time. It may be configured such that the amount of data of the stored frame is larger than a predetermined amount.

Embodiment 4 FIG.
In the first embodiment, when the video and audio playback delay is longer than the predetermined time T (ms), the subsequent processing is performed until the playback delay reaches the predetermined time T (ms). The projector 1 configured so as not to perform the synchronization process until the delay is eliminated has been described.

  In the second embodiment, when the playback delay of video and audio becomes longer than the predetermined time T (ms), the subsequent processing is performed until the playback delay reaches the predetermined time T (ms). The projector 1 configured to shorten the synchronization time until the delay is eliminated has been described.

  On the other hand, in the present embodiment, when the video and audio reproduction delay is longer than the predetermined time T (ms), the synchronization process is not performed only when the usage rate of the CPU 10 is equal to or lower than the predetermined usage rate. Alternatively, the projector 1 configured to shorten the synchronization time will be described. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that it is possible to reduce the reproduction delay while preventing an increase in the processing load of the CPU 10.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, about the structure which attaches | subjects the code | symbol similar to Embodiment 1, it shall show the same or an equivalent part, and abbreviate | omits detailed description.

  First, a method for reducing reproduction delay in the video display system according to the present embodiment will be described with reference to FIGS. FIG. 13 and FIG. 14 are flowcharts for explaining a method for reducing reproduction delay in the video display system according to the present embodiment. In FIGS. 13 and 14, only the parts different from FIG. 9 will be described.

  As shown in FIG. 13, in the video display system according to this embodiment, the main control unit 101 performs processing in S <b> 1311 corresponding to S <b> 911, and then sends the CPU 10 to the CPU usage rate measurement unit 115. The usage rate is measured (S1312).

  Then, the main control unit 101 determines whether or not the usage rate of the CPU 10 measured in S1312 is equal to or lower than a predetermined usage rate (S1313).

  When the main control unit 101 determines in the determination process in S1313 that the usage rate of the CPU 10 is higher than the predetermined usage rate (S1313 / NO), the main control unit 101 performs the same processing as the processing after S1306 corresponding to S906.

  On the other hand, when the main control unit 101 determines in the determination process in S1313 that the usage rate of the CPU 10 is equal to or lower than the predetermined usage rate (S1313 / YES), the main control unit 101 performs similar processing such as the processing after S1314 corresponding to S913. .

  As another example, if the main control unit 101 determines in the determination process in S1413 corresponding to S1313 that the usage rate of the CPU 10 is higher than the predetermined usage rate (S1413 / NO), it corresponds to S919. The same processing as S1420 and subsequent processing is performed.

  As described above, in the video display system according to the present embodiment, when the playback delay of video and audio is longer than the predetermined time T (ms), the projector 1 uses the CPU 10 with a usage rate equal to or lower than the predetermined usage rate. The synchronization process is not performed only in a certain case, or the synchronization time is shortened. In the video display system according to the present embodiment, the projector 1 is configured as described above, so that it is possible to reduce the reproduction delay while preventing an increase in the processing load of the CPU 10.

1 Projector 2 Client terminal 3 Network 3
10 CPU
20 RAM
30 ROM
40 HDD
50 Output device 60 Input device 70 Communication I / F
80 Bus 101 Main control unit 102 Reception unit 103 Queue 104 Decoder 105 Synchronization control unit 106 Projection control unit 107 Projection unit 108 Audio output control unit 109 Audio output unit 110 Elapsed time measurement unit 111 Difference time calculation unit 112 Accumulated time calculation unit 113 Accumulation Time storage unit 114 Frame number counting unit 115 CPU usage rate measuring unit 201 Main control unit 202 Display control unit 203 Display unit 204 Audio output control unit 205 Audio output unit 206 Capture unit 207 Encoder 208 Transmission unit

JP 2014-093584 A

Claims (8)

A data acquisition unit for acquiring data from an external device;
A content playback unit that plays back content for data that has been processed for playback of the content among the data acquired from the external device;
A delay occurrence determination unit that determines whether a delay has occurred in the processing for the data acquired from the external device;
A synchronization control unit for controlling a synchronization process for data acquired later than the acquired data according to a determination result of whether or not the delay has occurred;
A content playback apparatus comprising:   The synchronization control unit controls so that the synchronization process is not performed when it is determined that a delay has occurred in the process for the data acquired from the external device, or the synchronization process, 2. The content reproduction apparatus according to claim 1, wherein control is performed so as to be performed in a synchronization time shorter than a normal synchronization time.   The delay occurrence determination unit determines that a delay has occurred in the processing for the data when the time required for the processing for the data acquired from the external device is longer than a predetermined time. The content reproduction apparatus according to claim 1 or 2. A data storage unit for storing the data until the processing for the data acquired from the external device is started;
The delay occurrence determination unit, when the number of data stored in the data storage unit is a predetermined number or more, or when the data amount of data stored in the data storage unit is a predetermined amount or more, 4. The method according to claim 1, wherein it is determined that a delay has occurred in the processing for data acquired from the external device prior to the data stored in the data storage unit. 5. Content playback device. A usage rate measurement unit that measures the usage rate of computing devices
The synchronization control unit determines that a delay has occurred in the processing for the data acquired from the external device, and the synchronization processing is not performed when the measured usage rate is smaller than a predetermined usage rate. 5. The content reproduction apparatus according to claim 1, wherein the control is performed in such a manner that the synchronization processing is performed in a synchronization time shorter than a normal synchronization time.   The synchronization control unit performs control so that the synchronization process is not performed until the delay is eliminated, or the synchronization process is performed in a synchronization time shorter than a normal synchronization time. The content reproduction apparatus according to claim 1, wherein Acquire data from an external device,
Among the data acquired from the external device, the content is reproduced for the data that has been processed for content reproduction,
Determining whether a delay has occurred in the processing for the data acquired from the external device;
A content reproduction method characterized by controlling a synchronization process for data acquired after the acquired data according to a determination result of whether or not the delay has occurred. Obtaining data from an external device;
A step of reproducing content with respect to data for which processing related to content reproduction has been completed among the data acquired from the external device;
Determining whether a delay has occurred in the processing for the data acquired from the external device;
Controlling a synchronization process for data acquired later than the acquired data according to a determination result of whether or not the delay has occurred;
A content reproduction program for causing an information processing apparatus to execute