JP2000236519A - Video/audio reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video/audio reproducing device that a time margin until a designated operation is started can be increased without increasing the hardware scale. SOLUTION: A decoder repetitively outputs a video signal 53 and an audio signal 54 of a frame (F3 frame) next to a frame (F2 frame) reproduced at present in response to a pause signal 56. A control circuit outputs a video write control signal 62 and an audio write control signal 60 when outputting the pause signal 56. Then a video signal 53 of the F2 frame is received by a video 1-frame storage circuit and the audio signal 54 of the F2, F3 frames is received by an audio 2-frame storage circuit. When reproduction start is instructed, the control circuit turns off the pause signal 56 at a head of a succeeding frame and outputs the video write control signal 62 again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video / audio reproducing apparatus which can reproduce a video signal and an audio signal stored in a storage device or a storage medium after cueing.

[0002]

2. Description of the Related Art As a performance required for a video / audio reproduction apparatus, the reproduction of a video signal and an audio signal is started after a video signal and an audio signal stored in a storage device or a storage medium are located. Is required. At this time, it is required to start playback from the next frame to which a playback start instruction has been given, after locating the beginning and enabling the user to check the video to be played back next.

FIG. 5 shows a video / audio reproducing apparatus which can meet such a demand. In the configuration shown in FIG. 5, the encoded data 51 stored in the large-capacity storage circuit 1 is output to the decoder 21 according to a control signal 57 from the control circuit 5C. Then, the decoder 21
Thus, a valid period signal 55 indicating the valid period of the video signal 53, the audio signal 54, and the decoded data is output. In addition,
The control circuit 5C controls the entire device according to a control signal 59 input from the outside. The output of the encoded data 51 from the large-capacity storage circuit 1 is stopped in response to the supply stop signal 52 from the decoder 21.

[0004] The video signal 53 is stored in the video 1 frame storage circuit 3 in accordance with the video write control signal 62 output from the control circuit 5C. The video one-frame storage circuit 3 is configured so that when the video signal 53 is first written, the content is repeatedly output thereafter. Therefore, when the data writing is interrupted, the stored contents are repeatedly output. The audio signal 54 is stored in the audio 1 frame storage circuit 9 according to the audio writing control signal 60 output from the control circuit 5C.

The output 63 of the video one frame storage circuit 3 is
Video output interface circuit (video output I / F circuit) 7
Is converted into, for example, the format of CCIR recommendation 656 and output as a video output signal 65. The output 64 of the audio 1 frame storage circuit 9 is output to the audio output interface circuit (audio output I / F circuit) 8 according to the audio read signal 61 output from the control circuit 5C, and the audio output I / F
The signal is converted into a format of, for example, CCIR recommendation 647 by the F circuit 8 and output as an audio output signal 66.

The synchronizing signal generating circuit 6 is a known circuit, and generates a reference clock signal, a frame synchronizing signal, and the like required in the apparatus by using the reference signal 58 as an input, and supplies it to each block in the apparatus. . The control circuit 5C is a known circuit, for example, is configured by a microprocessor, and operates using a frame synchronization signal as an interrupt signal.

Next, the operation will be described with reference to the timing chart of FIG. When the reproduction standby is designated by the control signal 59, the control circuit 5C transmits standby information to the large-capacity storage circuit 1 by the control signal 57. Then, the encoded data 51 is stored in the large-capacity storage circuit 1.
Is output to the decoder 21, and the video signal 53 and the audio signal 54 are reproduced and output from the decoder 21. The decoder 21 also outputs a valid period signal 55 indicating that the video signal 53 and the audio signal 54 are being output.

The control circuit 5C monitors the validity period signal 55, supplies a pause signal 56 to the decoder 21 in the frame to be searched, and temporarily stops the decoder 21. In the example shown in FIG. 6, the frame to be searched for is the F2 frame. In response to the pause signal, the decoder 21 repeatedly outputs the video signal 53 and the audio signal 54 of the F2 frame. Further, it outputs a supply stop signal 52 to the large capacity storage circuit 1.

The control circuit 5C outputs a video write control signal 62 and an audio write control signal 60. Therefore, the video signal 53 and the audio signal 54 of the F2 frame are taken into the video 1 frame storage circuit 3 and the audio 1 frame storage circuit 9. However, the control circuit 5C sets the audio read control signal 61 to the non-read state so that no audio is output during the cueing process.

In this state, as shown in FIG. 6, a video signal of the F2 frame is repeatedly output as the video output signal 65. That is, the frame still is performed, and the user can check the video at the cueing position.

When reproduction start (start) is instructed by the control signal 59, the control circuit 5C releases the pause signal 56. That is, it is turned off. Then, the decoder 21 turns off the supply stop signal 52. Therefore,
The video signal and the audio signal are sequentially reproduced and output from the decoder 21 from the F2 frame.

As described above, the video signal of the frame to be searched for is repeatedly played back so that the image can be confirmed, and when a start instruction is given, each of the video signal and the audio signal is changed from the search position. The frames are sequentially reproduced and output.

However, referring to FIGS. 5 and 6, in the apparatus shown in FIG. 5, there is a time margin from when the decoder 21 receives the temporary stop command to when the decoder 21 stops (specifically, starts the still operation). Has only one frame. In addition, the decoder 21 has at most one frame of time from receiving the start command to restarting the normal decoding operation. Therefore, when realizing the device shown in FIG.
The time margin for control is reduced, and the system configuration method becomes difficult. The small time margin means that the operation according to the command must be started in a short time after receiving the command.

As one solution for increasing the time margin for control, it is conceivable to increase the capacity of a storage circuit that performs a buffer effect on the output side of the decoder 21. FIG.
FIG. 3 is a block diagram showing a playback apparatus provided with a video N frame storage circuit 10 and an audio N frame storage circuit 11 each capable of storing data for N (N is 2 or more) frames.

In the configuration shown in FIG. 7, as shown in FIG. 8, a video N frame storage circuit 10 and an audio N frame storage circuit 11 are used as a ring buffer. Then, the control circuit 5D increments the write address specified by the write control signal 67, and the output of the decoder 21 is sequentially written to each storage area of the video N frame storage circuit 10 and the audio N frame storage circuit 11. And the write address specified by the write control signal 67 is incremented, and the read address specified by the read control signal 68 is incremented. Control is performed so that data is output in order from each of the 11 storage areas.

According to the configuration shown in FIG. 7, since there is a margin in the storage capacity, a sufficient time margin from when the decoder 21 receives the instruction to when the decoder 21 starts the operation can be secured. However, since the storage capacity must be increased, the hardware scale increases and the cost increases.

[0017]

As described above, after cueing of a video signal and an audio signal stored in a storage device or a storage medium, the video signal and the audio signal can be reproduced. / The sound reproducing apparatus has a problem that a time margin from receiving a command for suspension or start to starting an operation according to the command is small. That is, a situation arises in which the operation must be started within a very short time after receiving the command.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a video / audio reproducing apparatus which can increase a time margin before starting a designated operation without increasing a hardware scale.

[0019]

A video / audio reproducing apparatus according to the present invention enters a still reproduction state from a frame next to a frame currently being decoded in response to a pause signal, and responds to cancellation of the pause signal in response to release of the pause signal. A decoder that returns from the playback state to the playback state;
A video one-frame storage circuit for storing frames and outputting stored contents, an audio two-frame storage circuit for storing two frames of audio signals from a decoder and outputting stored contents, and a cue when a standby signal is input from outside And a control circuit for outputting a pause signal at the time of reproduction of the target frame and releasing the pause signal at the end of the frame period of the signal output by the decoder when a start signal is input from the outside.

The control circuit provides a video write control signal so that the video one frame storage circuit resumes capturing the video signal when the pause signal is released, and from that point on, the decoder starts decoding one frame. The audio two-frame storage circuit is configured to supply an audio writing control signal so as to restart the capture of the audio signal when the processing is completed. Since the pause signal is released when the frame period of the signal output from the decoder ends after the start signal is input from the outside, the control circuit outputs the video write control signal and the audio write control signal. Sufficient time margin is given before doing so.

The control circuit may be configured to input a valid period signal indicating a valid period of the decoded data from the decoder and determine a pause signal output timing. According to such a configuration, when the MPEG2 encoding method is used, a GOP can be easily recognized, and a pause signal can be output at an appropriate timing.

At the start of the output of the pause signal, the control circuit
The video one frame storage circuit may be configured to supply a video write control signal so as to capture one frame of video signal. According to such a configuration, the video one-frame storage circuit can easily output the decoded frame video signal at the time of outputting the pause signal as a still image.

The control circuit operates until the pause signal is released.
The audio read control signal for the audio two-frame storage circuit may not be set to the read state. According to such a configuration, no sound is output during the cueing operation.

The audio 2 frame storage circuit inputs a valid period signal indicating the valid section of the decoded data from the decoder as an audio write control signal. It may be configured to provide an audio readout control signal so as to output an audio signal for two frames. According to such a configuration, even if the read control signal for the audio two-frame storage circuit is substituted by the validity period signal from the decoder, the audio is reproduced without interruption from the release of the pause signal. Therefore, output control of the audio writing control signal of the control circuit can be eliminated.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a video / audio reproducing apparatus according to the present invention. FIG.
In the configuration shown in FIG. 5, the encoded data 51 stored in the large-capacity storage circuit 1 is transmitted by the control signal 5 from the control circuit 5A.
7 is output to the decoder 2. Then, the decoder 2 outputs a video signal 53, an audio signal 54, and a valid period signal 55 indicating a valid period of the decoded data. The control circuit 5A controls the entire device according to a control signal 59 input from the outside. The output of the encoded data 51 from the large-capacity storage circuit 1 is stopped according to the supply stop signal 52 from the decoder 2.

The video signal 53 is stored in the video 1 frame storage circuit 3 in accordance with the video writing control signal 62 output from the control circuit 5A. This video one frame storage circuit 3
Is configured so that when the video signal 53 is first written, the stored content is repeatedly output thereafter. Therefore, when the data writing is interrupted, the stored contents are repeatedly output.

The audio signal 54 is stored in the audio 2 frame storage circuit 4 in accordance with the audio write control signal 60 output from the control circuit 5A. The audio 2 frame storage circuit 4
It has a capacity capable of storing audio signals for frames, and has a FIFO structure in which stored contents are sequentially output according to an audio read control signal 61 output from the control circuit 5A.

The output 63 of the video one frame storage circuit 3 is
The video output I / F circuit 7 converts the data into, for example, the format of CCIR recommendation 656 and outputs the converted video output signal 65. The output 64 of the audio two-frame storage circuit 4 is output to the audio output I / F circuit 8 in accordance with the audio read signal 61 output from the control circuit 5A, and is converted by the audio output I / F circuit 8 into, for example, the format of CCIR recommendation 647. The signal is output as an audio output signal 66.

The synchronization signal generating circuit 6 receives the reference signal 58 as an input, creates a reference clock signal, a frame synchronization signal, and the like required in the apparatus, and supplies them to each block in the apparatus. Further, the control circuit 5A is constituted by a microprocessor, for example, and operates using a frame synchronization signal as an interrupt signal.

Next, the operation will be described with reference to the timing chart of FIG. When the reproduction standby is designated by the control signal 59, the control circuit 5A transmits the standby information to the large-capacity storage circuit 1 by the control signal 57. Then, the encoded data 51 is output from the large-capacity storage circuit 1 to the decoder 2, and the video signal 53 and the audio signal 54 are reproduced and output from the decoder 2. The decoder 2 also outputs a valid period signal 55 indicating that the video signal 53 and the audio signal 54 are being output.

When the encoded data 51 is encoded by the MPEG2 system, the encoding is performed in GOP units. For example, if one GOP is composed of 15 frames, even if it is desired to reproduce the 15th frame, it is necessary to reproduce the GOP from the beginning. The validity period signal 55 is also used to notify what frame the decoder 2 is decoding.

The control circuit 5A monitors the validity period signal 55, and supplies a pause signal 56 to the decoder 2 in the frame to be searched. In the example shown in FIG. 6, the frame to be searched for is the F2 frame.

The decoder 2 responds to the pause signal 56 by
The video signal 53 and the audio signal 54 of the frame (F3 frame in this example) next to the currently reproduced frame (F2 frame) are repeatedly output. Further, it outputs a supply stop signal 52 to the large capacity storage circuit 1. In order to repeatedly output the frame next to the currently reproduced frame, for example, the decoder 2 only needs to confirm the presence or absence of the pause signal 56 at the end of reproduction of each frame. In the configuration shown in FIG. 5, it was necessary to shift to the frame still state in the frame currently being reproduced.
In this embodiment, the next frame that was being reproduced when the pause signal 56 was received may be reproduced, so that there is sufficient time for control.

When the pause signal 56 is output, the control circuit 5A outputs a video write control signal 62 and an audio write control signal 60 as shown in FIG. Therefore, the video signal 53 of the F2 frame is taken into the video 1 frame storage circuit 3. Further, the audio signal 54 of the F2 frame and the F3 frame is taken into the audio 2 frame storage circuit 4. However, the control circuit 5A sets the audio read control signal 61 to the non-read state so that no audio is output during the cueing process.

In this state, the video signal of the F2 frame is repeatedly output as the video output signal 65 as shown in FIG. That is, the frame still is performed, and the user can check the video at the cueing position.

When the start of reproduction is instructed by the control signal 59, the control circuit 5A turns off the pause signal 56 at the beginning of the next frame. Also, the video writing control signal 62 is output again. Therefore, the video signal 53 output from the decoder 2 is stored in the video 1 frame storage circuit 3
Will be taken into the state. At this stage, the video signal 53 of the F3 frame is still output from the decoder 2. Then, the decoder 2 turns off the supply stop signal 52. Then, the large-capacity storage circuit 1 restarts the output from the encoded data 51 of the F4 frame. Therefore, thereafter, the video signals are sequentially reproduced and output.

The control circuit 5A does not need to release the pause signal 56 immediately after the start signal is input. The pause signal 56 may be released at the end of the frame currently being decoded by the decoder 2. In the configuration shown in FIG. 5, the control circuit 5C had to release the pause signal 56 immediately (see FIG. 6). Therefore, also in this case, there is a margin in control time.

When canceling the pause signal 56, the control circuit 5A sets the voice read control signal 61 to a read state. Then, the audio 2 frame storage circuit 4 starts outputting the audio signal of the F2 frame. Since the audio two-frame storage circuit 4 stores data for two frames,
The control circuit 5A may re-output the audio writing control signal 60 when the decoder 2 stops the still operation and returns to the normal decoding state, that is, when the decoding of the F4 frame is started. Thereafter, the audio signals are sequentially reproduced and output.

As described above, the video signal of the frame to be searched for is repeatedly reproduced, and the image can be confirmed. When a start instruction is given, each of the video signal and the audio signal is changed from the search position. The frames are sequentially reproduced and output.

In this embodiment, the decoder 2 has a relatively small storage capacity (one frame for video and two frames for audio) and stops after receiving a command for temporary stop (specifically, (The start of the still operation) can be extended to about two frames. This means that in FIG.
It is shown that there is a time of about 2 frames from when the decoder 6 turns on to when the decoder output signal enters the still state.

Further, in this embodiment, there is a time margin of one frame or more from when the start signal is input to when the decoder 2 resumes the normal decoding operation.

FIG. 2 is a block diagram showing another embodiment of the present invention. In the configuration shown in FIG. 3, the control circuit 5B
Does not supply the audio write control signal to the audio 2 frame storage circuit 4. Instead, the validity period signal 55 is supplied to the audio 2 frame storage circuit 4, and the audio 2 frame storage circuit 4 uses the validity period signal 55 as a voice write control signal.

The operation will be described below with reference to the timing chart of FIG. Since the valid period signal 55 is supplied to the audio 2 frame storage circuit 4 as an audio writing control signal, in the example shown in FIG. 4, after the standby is input, the audio signals of the F0 frame to the F3 frame are output as audio signals. The data is written to the two-frame storage circuit 4. Also, the control circuit 5B
Gives the audio read control signal 61 for two frames to the audio two frame storage circuit 4. Therefore, the data of the F2 frame and the F3 frame remain in the audio 2 frame storage circuit 4.

Therefore, the control circuit 5 responds to the start signal.
When B again puts the audio read control signal 61 in the read state, the audio 2 frame storage circuit 4 can start outputting from the audio signal of the F2 frame.

In this case, since the control circuit 5B does not handle the audio writing control signal, the control load is reduced.
If data exceeding two frames is input to the audio two-frame storage circuit 4, new data is overwritten with old data. However, even if the audio read control signal 61 is not set to the read state, the data of the F2 frame and the F3 frame remain after all.

Even with such a configuration, in the decoder 2, it is possible to extend the time margin from receiving the temporary stop instruction to stopping (specifically, starting the still operation) to about two frames. it can. Further, there is a time margin of one frame or more from when the start signal is input to when the decoder 2 resumes the normal decoding operation.

Although the valid period signal 55 is common to the video signal 53 and the audio signal 54 in each of the above embodiments, they may be separate. In that case, audio 2
The frame storage circuit 4 is supplied with an audio valid period signal.

[0048]

As described above, according to the present invention, video / video
A decoder that enters the still playback state from the frame next to the frame currently being decoded in response to the pause signal and returns from the still playback state to the playback state in response to the release of the pause signal; and a video signal from the decoder. For storing one frame and outputting the stored contents, a two-frame storing circuit for storing two frames of audio signals from the decoder and outputting the stored contents, and when a standby signal is input from the outside. Since the pause signal is output at the time of reproduction of the cue target frame and a control circuit is configured to release the pause signal at the end of the frame period of the signal output by the decoder when a start signal is input from the outside, Without increasing the hardware scale,
This has the effect of increasing the time margin until the designated operation is started.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a video / audio reproduction device according to the present invention.

FIG. 2 is a timing chart showing an operation of the video / audio reproduction device shown in FIG.

FIG. 3 is a block diagram showing another embodiment of the video / audio reproduction device according to the present invention.

FIG. 4 is a timing chart showing an operation of the video / audio reproduction device shown in FIG. 3;

FIG. 5 is a block diagram showing a video / audio reproduction device as a comparative example of the present invention.

6 is a timing chart showing an operation of the video / audio reproduction device shown in FIG.

FIG. 7 is a block diagram showing a video / audio reproduction device as another comparative example of the present invention.

8 is an explanatory diagram showing an operation of the video / audio reproduction device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Large-capacity storage circuit 2 Decoder 3 Video 1 frame storage circuit 4 Audio 2 frame storage circuit 5A, 5B control circuit 6 Synchronous signal generation circuit 7 Video I / F circuit 8 Audio I / F circuit

Claims (6)

[Claims] 1. A video / audio reproducing apparatus capable of decoding stored data of a video signal and an audio signal, reproducing the data after cueing, and decoding the data in accordance with a pause signal. A decoder that returns to the reproduction state from the still reproduction state in response to the release of the pause signal while entering the still reproduction state from the frame following the current frame, and stores the video signal from the decoder for one frame and outputs the stored contents. A one-frame video storage circuit for storing an audio signal, a two-frame audio storage circuit for storing two frames of audio signals from the decoder and outputting the stored contents, and a pause signal when a cue target frame is reproduced when a standby signal is input from outside. Output a signal, and when a start signal is input from the outside, at the end of the frame period of the signal output by the decoder, A video / audio reproduction device comprising: a control circuit for canceling a pause signal. 2. The control circuit supplies a video writing control signal so that the video one frame storage circuit resumes capturing of the video signal when the pause signal is released, and from that point on, the decoder starts decoding one frame. Voice 2 when finished
2. The video / audio reproduction apparatus according to claim 1, wherein the frame storage circuit supplies an audio write control signal so as to restart the capture of the audio signal. 3. The video / audio reproducing apparatus according to claim 1, wherein the control circuit determines a pause signal output timing by inputting a valid period signal indicating a valid period of the decoded data from the decoder. 4. The video / video signal according to claim 1, wherein the control circuit supplies a video write control signal so that the video one-frame storage circuit takes in the video signal for one frame when the output of the pause signal is started. Audio playback device. 5. The video / audio reproduction apparatus according to claim 1, wherein the control circuit does not set the audio read control signal for the audio two-frame storage circuit in a read state until the pause signal is released. 6. An audio 2 frame storage circuit inputs a valid period signal indicating an effective section of decoded data from a decoder as an audio write control signal, and the control circuit outputs the audio 2 frame at the start of a pause signal output. 5. An audio reading control signal for outputting an audio signal for two frames from a storage circuit.
The video / audio reproduction device according to the above.