JP4641023B2 - Video signal playback device - Google Patents

Description

  The present invention relates to a video signal reproducing apparatus for reproducing a received and recorded video signal.

  In the conventional video signal reproduction apparatus, when the reproduction time is shortened, the frames are periodically thinned out and fast-forwarded.

  For example, in a TV broadcast recording / playback device, there is a catch-up playback function that catches up with a scene being broadcast by reducing the playback time by special playback when a past scene is being played back. The video signal reproduction apparatus described in Patent Document 1 below proposes a method such as fast-forwarding or selectively reproducing a scene with a high audio level. Also, when fast-forwarding a video signal compressed in MPEG, the video signal playback device described in Patent Document 2 below normally plays back only I pictures, but it is unnatural if the number of I pictures per unit time is small. Therefore, a method has been proposed in which only the low-order orthogonal transform coefficients are restored for P-pictures and B-pictures so that they can be processed at high speed and the frame decimation rate is increased.

JP 2001-119671 A JP-A-7-154743

  However, since the conventional video signal reproducing apparatus is configured to periodically skip frames and fast-forward, there is a problem in that the motion of the video becomes unnatural or discontinuous, and there is a sense of incongruity during viewing.

  The present invention has been made to solve such a problem. When the playback time of video is shortened, or when a past scene is played back to catch up with a scene being broadcast, the motion of the video is unnatural or unnatural. It is an object of the present invention to provide a video signal reproducing apparatus that can thin out frames so that it is not felt that the speed is continuously increased, thereby obtaining a smoother image.

A video signal reproduction apparatus according to the present invention is a video signal reproduction apparatus that outputs an input video signal to a display device, and stores video input means for storing the input video signal, and a frame of the video signal output from the video storage means. It analyzes the changes, and frame display determining means for determining whether or not to display each frame on the display device, based on the display permission information output from the frame display determining means, video signal output from said video storage means And a control means for controlling the output frequency of the video signal from the video storage means, and the frame display determination means includes the video signal output from the video storage means. And a predetermined number of frames after the scene change is determined not to be displayed .

According to a first aspect of the present invention, a change in each frame is analyzed, and it is determined whether or not to display each frame . When there is a scene change, a predetermined number of frames after the scene change is determined. Is determined not to be displayed. As a result, there is an effect that the playback time of the video can be shortened without a sense of incongruity so that the viewer cannot feel that the motion of the video has become faster.

[Embodiment 1]
FIG. 1 is a block diagram showing a TV signal display device using a video signal reproduction device 100 according to Embodiment 1 of the present invention. The configuration will be described below with reference to FIG.

  The TV signal display device controls an antenna 1 that receives a TV broadcast signal, a tuner 2 that demodulates the broadcast signal output from the antenna 1 and outputs a video signal, and a video signal output from the tuner 2 for output. The video signal reproduction device 100 and a display device (hereinafter referred to as a display 7) for displaying a video signal output from the video signal reproduction device 100 are included.

  Next, the video signal reproduction apparatus 100 includes video storage means (hereinafter referred to as a memory 3) for storing the video signal output from the tuner 2, the video signal output from the tuner 2, and the video signal output from the memory 3. Switching means 4 for switching and outputting, decoder 5 for decoding the video signal output from the switching means 4, switching means 6 for switching the frame decoded by the decoder 5 to output to the display 7, and decoding by the decoder 5 A frame display determining means 8 for analyzing the frame and determining whether or not to display each frame on the display 7; display enable / disable information output from the frame display determining means 8; an external control signal; and a reading position from the memory 3. Based on the information of the writing position, the switching means 6 is controlled whether or not to output a video signal to the display 7, and the memory 3, decoder The output frequency of the video signal from, a control unit 9 for controlling the switching of the switching means 4.

  Next, the operation of the video signal reproduction apparatus 100 will be described.

  Here, the control means 9 has external control signals indicating “normal reproduction” and “rewind reproduction” as inputs. First, when a signal indicating “normal reproduction” is input to the control unit 9, the control unit 9 controls the switching unit 4 to select the output of the tuner 2, and the switching unit 6 decodes the decoder 5. Controls to output always the frame.

  In this case, the broadcast signal received by the antenna 1 is demodulated by the tuner 2, the video signal output from the tuner 2 is decoded by the decoder 5, and the frame output from the decoder 5 is directly displayed on the display 7 via the switching means 6. Is displayed. Therefore, in this case, the signal being broadcast can be viewed in real time. Here, in the case of digital broadcasting, since the video signal output from the tuner 2 is a video stream compressed by a method such as MPEG-2, the decoder 5 decodes the video stream and decodes the decoded frame. Is output.

  In this case, the video signal stored in the memory 3 is not output from the switching means 4, but the video signal output from the tuner 2 is always stored in the memory 3, and the writing position to the memory 3 is controlled. The means 9 is notified. The memory 3 is configured, for example, as a ring buffer, and is configured to continue to accumulate video signals from the tuner 2 by controlling to write back to the top address after writing to the end of the physical address.

  Next, an operation when a signal indicating “rewinding reproduction” is input to the control means 9 will be described.

  First, the control means 9 sets in the memory 3 a position returned from the writing position of the memory 3 by an amount corresponding to the rewinding time specified by the external control signal as a reading position. The control unit 9 controls the switching unit 4 so as to select the video signal output from the memory 3. The memory 3 outputs the video signal accumulated from the designated reading position. Therefore, in this case, the video signal delayed in the memory 3 by the rewind time specified by the external control signal is input to the decoder 5, and the decoded frame is input to the frame display determination means 8.

  Next, the frame display determination means 8 analyzes the frame decoded by the decoder 5 and determines whether to display each frame. At this time, the frame display determination means 8 determines that a frame that does not stand out even if thinned is not displayed, and that a frame whose movement looks unnatural when thinned is displayed.

  For example, when there is a scene change, even if one frame or a plurality of frames before and after the scene change is thinned out, it is not visually conspicuous. In addition, in a still image or a scene with extremely little motion, even if the frame is periodically thinned out, it does not appear that the motion of the video is accelerated. Referring to FIG. 2, the frame display determining means 8 includes means for detecting a change between frames. When it is determined that the change between frames is very large and a scene change, a predetermined display after the scene change is performed. It is determined to thin out the number of frames. If the change between frames is extremely small, it is determined that the scene is a still scene, and the frame is determined to be thinned at a predetermined thinning rate. For example, this determination is made by providing the frame display determining means 8 with predetermined threshold values corresponding to scene changes and still scenes, and when the change between frames is equal to or greater than the threshold value corresponding to the scene change. If it is equal to or less than the threshold value corresponding to the still scene, it may be determined as a still scene.

  As a means for detecting a change between frames, there is a method for obtaining a sum of absolute values of frame differences, but in order not to erroneously detect a fast-moving scene as a scene change, the absolute value of the frame difference with motion compensation is used. It is better to use a method to find the sum. In order to cope with fade-out and fade-in, a weighted frame difference, a method of taking a frame difference after removing a DC component, and the like are also conceivable.

  As for fade-in and fade-out, if the scene being faded is short, it may be thinned out as a scene change. If the scene being faded is long, the scene gradually fade-in and fade-out will not change unnaturally. As described above, control may be performed so as not to thin out during fading.

  Next, the determination result of the frame display determination means 8 is input to the control means 9 as display enable / disable information. The control means 9 controls the switching means 6 in accordance with the input display availability information so that frames that are not displayed are not output to the display 7.

  Here, when the display possibility information output from the frame display determining means 8 indicates “not display”, the control means 9 controls the memory 3 to output a video signal corresponding to the next frame, Decoding is performed by the decoder 5. That is, when a signal indicating “rewind playback” is input as an external control signal, the switching means 6 is controlled according to the display enable / disable information of the frame display determining means 8 to limit the frames to be displayed, thereby shortening the video playback time. Therefore, when the external control signal indicates “rewind playback” and the frame display determination means 8 determines not to output the video signal to the display device, the memory 3 and the decoder 5 are more than in the case of “normal playback”. The control means 9 controls to operate at a fast frame rate and output the next frame.

  For example, when thinning out a maximum of 5 frames continuously, if the external control signal indicates “rewind playback”, the memory 3 and the decoder 5 are operated at a speed 5 times the normal speed, and each time a request is issued from the control means 9 Configure so that the next frame can be output.

  When the frame display determination means 8 detects a scene change and determines to thin out a plurality of frames, the control means 9 reads out the video signal stored in the memory 3 from the previous video signal by a predetermined number of thinned frames. You may control as follows.

  Note that the control means 9 assumes that the rewind reproduction is completed when the read position of the memory 3 catches up with the write position, and the output of the memory 3 is switched to the operation when the external control signal indicates “normal reproduction”. To control. That is, when the reading position of the memory 3 catches up with the writing position, the control means 9 controls the switching means 4 to select the output of the tuner 2 and the switching means 6 always outputs the frame decoded by the decoder 5. Therefore, only when a past scene is being played back, frames can be thinned out so that the motion of the video cannot be recognized, and normal playback can be resumed by catching up with the scene being broadcast.

  In the first embodiment, when the video signal output from the tuner 2 is an MPEG-2 stream including a B picture, rearrangement of output frames is necessary for decoding, but the decoder 5 rearranges the B picture. Assume that the frames after completion are sequentially output.

  As described above, according to the video signal reproduction apparatus 100 of the first embodiment, it is determined whether to display each frame by analyzing the change of each frame, and if it is determined not to display, the frame rate is increased. Therefore, it is possible to shorten the playback time of the video without a sense of incongruity so that the viewer does not feel that the video has moved faster.

[Embodiment 2]
FIG. 3 is a block diagram showing a TV signal display device using the video signal reproducing device 100a according to the second embodiment of the present invention. The configuration will be described below with reference to FIG.

  The TV signal display device controls an antenna 1 that receives a TV broadcast signal, a tuner 2 that demodulates the broadcast signal output from the antenna 1 and outputs a video signal, and a video signal output from the tuner 2 for output. The video signal reproduction apparatus 100a and the display 7 for displaying the video signal output from the video signal reproduction apparatus 100a.

  Next, the video signal reproducing device 100a switches the display 7 by switching the memory 3 for storing the video signal output from the tuner, the decoder 5 for decoding the video signal output from the memory 3, and the frame decoded by the decoder 5. Switching means 6 for outputting to the frame, frame display determining means 8 for analyzing whether the frame decoded by the decoder 5 is displayed on the display device, and display availability output from the frame display determining means 8 The switching means 6 is controlled based on the information, the external control signal, and the information on the reading position and writing position from the memory 3 to determine whether or not to output the video signal to the display 7, and the output frequency of the video signal from the memory 3 and the decoder 5. And control means 9 for controlling.

  Here, the second embodiment is different from the first embodiment in that the switching means 4 is not provided, and the video signal output from the tuner 2 is output to the decoder 5 via the memory 3. That is, when the external control signal indicates “normal reproduction” in the first embodiment, switching is performed if the video signal stored in the memory 3 is read with a slight time delay with respect to the writing position of the memory 3. The means 4 becomes unnecessary. For example, in the case of “normal playback”, it is only necessary to control the position one frame before the writing position in the memory 3 to be the reading position.

  Next, the operation of the video signal reproduction device 100a will be described.

  First, when a signal indicating “normal reproduction” is input to the control means 9a, the control means 9a controls the memory 3 to read the position one frame before the writing position, and the switching means 6 Control to always output the decoded frame.

  In this case, the broadcast signal received by the antenna 1 is demodulated by the tuner 2, and the video signal output from the tuner 2 is delayed by one frame in the memory 3 and decoded by the decoder 5. The frame output from the decoder 5 is displayed on the display 7 as it is. Therefore, in this case, the signal being broadcast can be viewed in real time.

  Next, an operation when a signal indicating “rewinding reproduction” is input to the control means 9a will be described. First, the control means 9a sets in the memory 3 the position returned from the writing position of the memory 3 by the amount corresponding to the rewind time specified by the external control signal as the reading position. Further, the control unit 9 a controls the switching unit 6 according to the display availability information output from the frame display determining unit 8 so that frames that are not displayed are not output to the display 7. Further, the control means 9a outputs from the memory 3 and the decoder 5 in accordance with the number of frames not to be displayed when the display possibility information output from the frame display determination means 8 indicates “not display”. Control is performed so that the frame rate of the video signal is increased.

  Therefore, in this case, the video signal delayed in the memory 3 by the rewind time specified by the external control signal is input to the decoder 5 and decoded, and further, the delay time in the memory 3 becomes shorter as the reproduction time advances. It is controlled to become.

  Note that the control means 9a assumes that the rewind reproduction is completed when the read position of the memory 3 catches up with the write position, and the output of the memory 3 is switched to the operation when the external control signal indicates “normal reproduction”. To control. That is, when the reading position of the memory 3 catches up with the writing position, the control means 9a controls the memory 3 to read the position one frame before the writing position, and the switching means 6 reads the frame decoded by the decoder 5. Control to always output.

  Since the operations other than the control unit 9a are the same as those in the first embodiment, the description thereof is omitted.

  As described above, according to the video signal reproduction apparatus 100a of the second embodiment, the external control signal indicating “normal reproduction” or “rewind reproduction” is input to the input, and the external control signal indicates “normal reproduction”. If so, the control means 9a controls the outputs of the memory 3 and the decoder 5 so that the video signal input to the memory 3 is output at the same frame rate as the input frame rate. When the external control signal indicates “rewind playback”, the control unit 9 a outputs the frame output from the decoder 5 to the display 7 based on the display availability information output from the frame display determination unit 8. If the frame is not output to the display 7, the output frame rate of the video signal from the memory 3 and the decoder 5 is controlled to be higher than the input frame rate. You can catch up with the scene being broadcast by thinning out the frames so that you don't know that the video is moving faster.

  When the read position of the memory 3 catches up with the write position, the video signal input to the memory 3 by the control means 9a is the same as the input frame rate regardless of the display enable / disable information output from the frame display determination means 8. Since the output of the memory 3 is controlled so as to be output at the frame rate, when the past scene is reproduced while reducing the time and catches up with the scene being broadcast, the normal reproduction can be resumed.

[Embodiment 3]
FIG. 4 is a block diagram showing a TV signal display device using the video signal reproducing device 100b according to the third embodiment of the present invention. The configuration will be described below with reference to FIG.

  The TV signal display device controls an antenna 1 that receives a TV broadcast signal, a tuner 2 that demodulates the broadcast signal output from the antenna 1 and outputs a video signal, and a video signal output from the tuner 2 for output. The video signal reproduction device 100b and the display 7 for displaying the video signal output from the video signal reproduction device 100b.

  Next, the video signal reproduction device 100 b includes a memory 3 that stores the video signal output from the tuner 2, a stream analysis unit 501 that analyzes a stream of the video signal output from the memory 3, and an output from the stream analysis unit 501. Coefficient decoding means 503 for decoding from the header information and transform coefficients to be performed, switching means 502 for switching whether to input the header information and transform coefficients output from the stream analysis means 501 to the coefficient decoding means 503, and a stream Analyzing the header information and conversion coefficient output from the analysis means 501, frame display determination means 8b for determining whether or not to display each frame, display enable / disable information output from the frame display determination means 8b, and external control signal And the switching means 502 are controlled based on the information of the reading position and writing position from the memory 3. Both composed of a control unit 9b for controlling the output frequency of the memory 3, a video signal from the stream analyzing means 501.

  The stream analysis unit 501, the switching unit 502, and the coefficient decoding unit 503 constitute a decoder 5b.

  In general, in the case of an encoding method using orthogonal transform such as MPEG-2, a video stream including a transform coefficient obtained by orthogonal transform and quantization and header information such as a coding mode and a quantization parameter is transmitted. Come. Accordingly, the decoder 5b is roughly divided into a stream analysis unit 501 that analyzes a video stream and extracts header information and transform coefficients, and a coefficient decoding unit 503 that performs inverse quantization and inverse orthogonal transform on the transform coefficients to decode a frame. .

  The third embodiment is configured such that the switching means 502 is provided between the stream analysis means 501 and the coefficient decoding means 503 constituting the decoder 5b, and the control means 9b is configured to control the switching means 502. Different from 2. This switching means 502 corresponds to the switching means 6 of the second embodiment. Further, the frame display determining unit 8b is different from the second embodiment in that it determines whether or not to display a frame from the header information and the conversion coefficient output from the stream analyzing unit 501 before all decoding operations are completed. .

  Next, the operation of the video signal reproduction device 100b will be described.

  First, when a signal indicating “normal reproduction” is input to the control unit 9b, the control unit 9b controls the memory 3 to read the position one frame before the writing position, and the switching unit 502 uses the stream analysis unit. Control is performed so that the header information and transform coefficients output from 501 are always output to the coefficient decoding means 503.

  In this case, the broadcast signal received by the antenna 1 is demodulated by the tuner 2, and the video signal output from the tuner 2 is delayed by one frame in the memory 3, and is decoded by the decoder 5b (stream analysis means 501 and coefficient decoding means 503). Decrypted. The frame output from the decoder 5b is displayed on the display 7 as it is. Therefore, in this case, the signal being broadcast can be viewed in real time.

  Next, the operation when a signal indicating “rewinding reproduction” is input to the control means 9b will be described. First, the control means 9b sets in the memory 3 the position returned from the write position of the memory 3 by the amount corresponding to the rewind time specified by the external control signal as the read position. Further, the control unit 9b controls the switching unit 502 according to the display availability information output from the frame display determination unit 8b so that header information and transform coefficients of frames not to be displayed are not output to the coefficient decoding unit 503. Further, when the display availability information output from the frame display determination unit 8b indicates “not display”, the control unit 9b outputs from the memory 3 and the stream analysis unit 501 according to the number of frames not to be displayed. To control the frame rate of the video signal to be increased.

  Therefore, in this case, the video signal delayed in the memory 3 by the rewind time specified by the external control signal is input to the stream analysis unit 501, and only the frame determined to be displayed by the frame display determination unit 8b is output by the coefficient decoding unit 503. Decoded and displayed on the display 7. Further, the control is performed so that the delay time in the memory 3 becomes shorter as the reproduction time advances.

  Note that the control means 9b assumes that the rewind reproduction is completed when the read position of the memory 3 catches up with the write position, and the output of the memory 3 is switched to the operation when the external control signal indicates “normal reproduction”. To control. That is, when the read position of the memory 3 catches up with the write position, the control means 9b controls the memory 3 to read the position one frame before the write position, and the switching means 502 is output from the stream analysis means 501. The header information and the transform coefficient are controlled so as to be always output to the coefficient decoding means 503.

  Next, the operation of the frame display determination unit 8b will be described.

  The frame display determination unit 8b uses the header information and the conversion coefficient output from the stream analysis unit 501, and does not display a frame that does not stand out even if it is thinned out, and displays a frame that looks unnatural when thinned out. Judge as something. For example, a scene change is detected by evaluating the magnitude of the DC component of the conversion coefficients output from the stream analysis unit 501. That is, in the case of orthogonal transformation after performing predictive encoding between frames as in the MPEG-2 P picture, the absolute value of the DC component becomes large in the case of a scene change. Therefore, when the average value or maximum value of the DC components in the frame is greater than or equal to a predetermined value, it is determined that the scene has changed, and one or more frames before and after the scene change are determined not to be displayed. In addition, in the case of an encoding method that performs predictive encoding between frames as in MPEG-2, a flag called Not Coded indicating the same as the previous frame is sent as header information. Therefore, when the flag indicating Not Coded is equal to or greater than a predetermined value in the frame, it is determined that the scene is a still image or a scene with extremely little motion, and the frame is periodically thinned out.

  In addition, when orthogonal transformation is performed within a frame, such as an MPEG-2 I picture, a change in the DC component from the previous frame is obtained, and when the change is large, it is determined as a scene change, and before and after the scene change. One frame or a plurality of frames are determined to be “not displayed”, and when the change in the DC component is small, it is determined that the frame is a still image or a scene with little motion, and the frame is periodically thinned out. For example, in this determination, the frame display determining means 8b is provided with predetermined threshold values corresponding to the scene change and the still scene, and the scene change is performed when the change between frames is equal to or greater than the threshold value corresponding to the scene change. If it is equal to or less than the threshold value corresponding to the still scene, it may be determined as a still scene.

  When the video signal output from the memory 3 is a video stream including bidirectional prediction such as an MPEG-2 B picture, the frame display determination unit 8b determines the scene change for only the I picture and the P picture. In the case of a scene change, a plurality of frames including the picture and the preceding and following B pictures are not displayed. If the image is a still picture, a continuous image including the picture and the preceding and following B pictures is displayed. The display availability information may be determined so that the frames are periodically thinned out.

  Even when the video signal is input as an encoded video stream in this way, there is an effect that the playback time of the video can be shortened so that the viewer does not feel that the motion of the video is fast.

  As described above, according to the video signal reproduction device 100b of the third embodiment, the decoder 5b analyzes the video stream to obtain the header information and the conversion coefficient, and based on the obtained conversion coefficient and header information. And a coefficient decoding unit 503 for decoding the video signal, analyzing the change of the frame based on the header information and the conversion coefficient output from the stream analysis unit 501, and determining whether to display each frame. Since it is configured, it is possible to determine whether or not to thin out a frame before all decoding operations are completed, and the processing time can be shortened.

[Embodiment 4]
FIG. 5 is a block diagram showing a TV signal display device using the video signal reproducing device 100c according to the fourth embodiment of the present invention. The configuration will be described below with reference to FIG.

  The TV signal display device includes an antenna 1 that receives a TV broadcast signal, a tuner 2 that demodulates the broadcast signal output from the antenna 1 and outputs a video signal, and a decoder 5 that decodes the video signal output from the tuner 2. The video signal reproducing device 100c controls and outputs the video signal output from the decoder, and the display 7 displays the video signal output from the video signal reproducing device 100c.

  Next, the video signal reproduction device 100 c includes a memory 3 that stores the video signal output from the decoder 5, a switching unit 6 that switches and outputs a frame output from the memory 3, and a frame output from the memory 3. Analyzing and determining whether or not to display each frame, frame display determining means 8, display enable / disable information output from the frame display determining means 8, external control signals, and information on the read position and write position from the memory 3 Based on this, the control unit 9 c is configured to control the switching unit 6 and to control the output frequency of the video signal from the memory 3.

  The fourth embodiment is different from the second embodiment in that the decoded frame is stored in the memory 3. In this case, the broadcast signal received by the antenna 1 is demodulated by the tuner 2, and the video signal output from the tuner 2 is decoded by the decoder 5 and stored in the memory 3.

  Next, the operation of the video signal reproduction device 100c will be described.

  First, when a signal indicating “normal reproduction” is input to the control unit 9 c, the control unit 9 c controls the memory 3 to read the position one frame before the writing position, and the switching unit 6 controls the memory 3. Controls to always output the output frame.

  In this case, the frame output from the decoder 5 is delayed by one frame in the memory 3 and displayed on the display 7. Therefore, in this case, the signal being broadcast can be viewed in real time.

  Next, an operation when a signal indicating “rewinding reproduction” is input to the control means 9c will be described. First, the control means 9c sets in the memory 3 the position returned from the write position in the memory 3 by the amount corresponding to the rewind time specified by the external control signal as the read position. Further, the control unit 9 c controls the switching unit 6 according to the display availability information output from the frame display determination unit 8 so that frames that are not displayed are not output to the display 7. Further, when the display availability information output from the frame display determination unit 8 indicates “not display”, the control unit 9c determines the video signal output from the memory 3 according to the number of frames not to be displayed. Control to increase the frame rate.

  Therefore, in this case, the frame delayed in the memory 3 by the rewind time specified by the external control signal is displayed on the display 7 and further controlled so that the delay time in the memory 3 becomes shorter as the playback time advances. Is done.

  Note that the control means 9c assumes that the rewind reproduction is completed when the read position of the memory 3 catches up with the write position, and outputs the memory 3 so that the operation is switched to the operation when the external control signal indicates “normal reproduction”. To control. That is, when the read position of the memory 3 catches up with the write position, the control means 9c controls the memory 3 to read the position one frame before the write position, and the switching means 6 outputs the frame output from the memory 3. Is controlled so that it is always output.

  Here, since the operations other than the control means 9c are the same as those in the second embodiment, the description thereof will be omitted.

  As described above, according to the video signal reproduction apparatus 100c of the fourth embodiment, the change of each frame is analyzed, and only the frames that the viewer cannot feel that the motion of the video is fast are thinned out. There is an effect that the playback time of the video can be shortened without a sense of incongruity. In the case of the configuration of the fourth embodiment, since the control means 9c does not need to control the decoder 5, there is an effect that the control of the control means 9c is simplified.

[Embodiment 5]
FIG. 6 is a block diagram showing a TV signal display device using the video signal reproducing device 100d according to the fifth embodiment of the present invention. The configuration will be described below with reference to FIG.

  The TV signal display device controls an antenna 1 that receives a TV broadcast signal, a tuner 2 that demodulates the broadcast signal output from the antenna 1 and outputs a video signal, and a video signal output from the tuner 2 for output. The video signal playback device 100d, the display 7 for displaying the video signal output from the video signal playback device 100d, and the speaker 12 for playing back the audio signal output from the video signal playback device 100d.

  Next, the video signal reproduction device 100d includes a memory 3 that stores the video signal output from the tuner 2, an AV separation unit 10 that separates the video signal output from the memory 3 into a video stream and an audio stream, and AV separation. The decoder 5 for decoding the video stream output from the means 10, the switching means 6 for switching and outputting the frame decoded by the decoder 5, and the playback speed of the audio stream output from the AV separation means 10 are converted and output. The audio speed conversion means 11 and the frame display determination means 8d for analyzing the frame decoded by the decoder 5 and determining whether to display each frame from the frame analysis result and the audio speed information in the audio speed conversion means 11. Display enable / disable information output from the frame display determination means 8d, the external control signal, and the read position from the memory 3. , Based on the information of the writing position, and controls the switching means 6, a memory 3, a decoder 5, AV separation unit 10, and a control means 9d for controlling the output frequency of the signal from the audio speed converter 11.

  In the fifth embodiment, when the video signal output from the tuner 2 is a signal in which a video stream and an audio stream are multiplexed, such as MPEG-2 Transport Stream, for example, an audio speed conversion that changes the audio playback speed is performed. The second embodiment is different from the second embodiment in that a means 11 is provided and the sound reproduction speed information in the sound speed converting means 11 is reflected in the frame display determining means 8d.

  Next, the operation of the video signal reproduction device 100d will be described.

  First, when a signal indicating “normal reproduction” is input to the control means 9d, the control means 9d controls the memory 3 to read the position one frame before the writing position, and the switching means 6 causes the decoder 5 to Control is performed so that the decoded frame is always output, and the audio speed converting means 11 reproduces the audio at the normal speed.

  In this case, the broadcast signal received by the antenna 1 is demodulated by the tuner 2, and the video signal output from the tuner 2 is delayed by one frame in the memory 3 and input to the AV separation means 10. The video stream output from the AV separation means 10 is decoded by the decoder 5, and the frame output from the decoder 5 is displayed on the display 7 as it is. The audio stream output from the AV separation unit 10 is output at a normal speed by the audio speed conversion unit 11 and reproduced by the speaker 12. Therefore, in this case, the signal being broadcast can be viewed in real time.

  Next, an operation when a signal indicating “rewinding reproduction” is input to the control means 9d will be described. First, the control means 9d sets in the memory 3 the position returned from the write position in the memory 3 by the amount corresponding to the rewind time specified by the external control signal as the read position. Further, the control means 9d performs control so that the voice speed converting means 11 outputs a voice signal at a predetermined fast feed speed. The frame display determination means 8d analyzes the frame output from the decoder 5 and determines a frame that is not conspicuous even if it is thinned out. This determination method is the same as in the first embodiment. Further, the frame display determination means 8d obtains the reproduction speed information of the audio output from the audio speed conversion means 11, and thins out a frame that is not conspicuous even if it is thinned out so that the difference between the video and the audio is within a predetermined time. Decide whether or not.

  Further, the control unit 9d controls the switching unit 6 according to the display possibility information output from the frame display determination unit 8d so that frames that are not displayed are not output to the display 7. Furthermore, when the display availability information output from the frame display determination unit 8d indicates “not display”, the control unit 9d determines that the memory 3, the AV separation unit 10, and the decoder according to the number of frames that are not displayed. Control is performed so that the frame rate of the video signal output from 5 is increased.

  Therefore, in this case, the video signal delayed in the memory 3 by the rewind time specified by the external control signal is input to the AV separation means 10, the decoder 5, and the audio speed conversion means 11, and further as the playback time advances, 3 is controlled to shorten the delay time.

  Note that the control means 9d assumes that the rewind reproduction is completed when the read position of the memory 3 catches up with the write position, and the output of the memory 3 is switched to the operation when the external control signal indicates “normal reproduction”. To control. That is, when the read position of the memory 3 catches up with the write position, the control unit 9d controls the memory 3 to read the position one frame before the write position, and the audio speed conversion unit 11 outputs the audio at the normal speed. Control is performed so that the switching means 6 always outputs the frame decoded by the decoder 5.

  The voice speed conversion means 11 may perform speed conversion at a constant rate when outputting a voice signal by fast-forwarding, or may realize fast-forwarding by detecting a silent part and thinning out the silent part. In addition, after the silent portion is thinned out, the remaining portions may be converted.

  As described above, according to the video signal reproduction device 100d of the fifth embodiment, the audio speed conversion unit 11 that shortens the reproduction time of the audio signal is provided, and the frame display determination unit 8d analyzes the change of each frame of the video signal. Then, since it is determined whether or not to display each frame from the analysis result and the audio speed information output from the audio speed conversion means 11, the viewer feels that the motion of the video has become faster. In addition to this, there is an effect that the playback time of the video can be shortened so that the unnaturalness of the sound is not felt.

  In the first to fifth embodiments, either “normal reproduction” or “rewind reproduction” is input as the external control signal. For example, “normal reproduction” is used as the external control signal. ”,“ Rewind normal playback ”, or“ Short playback at rewind ”is input, and the playback time may be shortened only during“ Short playback at rewind ”.

  In the first to fifth embodiments, the memory 3 is used as the means for storing the video signal. However, a storage medium such as a hard disk or a DVD may be used as the video storage means.

  Also, in the first to fifth embodiments, in the case of “rewind playback”, the frame is thinned out so as not to know that the motion of the video is fast, and is configured to catch up with the scene being broadcast. However, when the video signal output from the tuner 2 is temporarily stored in the memory 3 together with the program, and is played back / viewed after the program is played back, it can be played back with a similar configuration.

  In the first to fifth embodiments, the output of the tuner 2 is stored in the memory 3. However, the video signal stored in the memory 3 is not limited to the output of the tuner 2. Even when the video signal output from the video recording apparatus is played back, the video signal playback apparatus according to the first to fifth embodiments can be played back while reducing the time.

It is a block diagram which shows the TV signal display apparatus concerning Embodiment 1 of this invention. It is explanatory drawing showing operation | movement of the frame display determination means concerning Embodiment 1 of this invention. It is a block diagram which shows the TV signal display apparatus concerning Embodiment 2 of this invention. It is a block diagram which shows the TV signal display apparatus concerning Embodiment 3 of this invention. It is a block diagram which shows the TV signal display apparatus concerning Embodiment 4 of this invention. It is a block diagram which shows the TV signal display apparatus concerning Embodiment 5 of this invention.

Explanation of symbols

  1 antenna, 2 tuner, 3 memory, 4, 6,502 switching means, 5,5b decoder, 7 display, 8, 8b, 8d frame display determining means, 9, 9a, 9b, 9c, 9d control means, 10 AV separation Means 11 Sound speed conversion means 12 Speaker 100, 100a, 100b, 100c, 100d Video signal reproduction device 501 Stream analysis means 503 Coefficient decoding means.

Claims (10)

A video signal reproduction device for outputting an input video signal to a display device,
Video storage means for storing the input video signal;
Analyzing frame changes of the video signal output from the video storage means, and determining whether to display each frame on a display device;
Based on the display availability information output from the frame display determining means, it is controlled whether or not the video signal output from the video storage means is output to a display device, and the output frequency of the video signal from the video storage means is determined. Control means for controlling ,
The video signal reproducing apparatus , wherein the frame display determining means detects a scene change of the video signal output from the video storage means and determines not to display a predetermined number of frames after the scene change . A switching unit is further provided at a stage subsequent to the video storage unit, and a frame of the video signal output from the video storage unit is switched to the input video signal and output to the display device based on control information output from the control unit. The video signal reproducing apparatus according to claim 1, wherein:
Decoding means for decoding the video signal output from the video storage means before the frame display determination means,
2. The video signal reproducing apparatus according to claim 1, wherein the control means controls the output frequency of the video signal from the decoding means. The input video signal is a video stream encoded by an encoding method using orthogonal transform,
The decoding means includes
Stream analysis means for analyzing a video stream and obtaining header information and conversion coefficients;
Coefficient decoding means for decoding a video signal based on header information and conversion coefficients output from the stream analysis means,
4. The video signal reproduction according to claim 3, wherein the frame display determination means analyzes header information and conversion coefficients output from the stream analysis means and determines whether or not to display each frame on a display device. apparatus.   A switching means is further provided between the stream analysis means and the coefficient decoding means, and an output from the stream analysis means is input to the coefficient decoding means to the display device based on control information output from the control means. 5. The video signal reproducing apparatus according to claim 4, wherein switching is performed. The control means has an external control signal indicating whether it is “normal playback” or “rewind playback” as an input,
The control of the output frequency of the control means is
When the external control signal indicates “rewind playback” and the frame display determination means determines not to output the video signal to the display device, the frame rate is faster than when the video storage means is “normal playback”. 2. The video signal reproducing apparatus according to claim 1, wherein the video signal reproducing apparatus is controlled so as to operate at the same time. The control means has an external control signal indicating whether it is “normal playback” or “rewind playback” as an input,
The control of the output frequency of the control means is
When the external control signal indicates “rewind playback” and the frame display determination unit determines not to output the video signal to the display device, the frame rate is faster than when the decoding unit is “normal playback”. 4. The video signal reproducing apparatus according to claim 3, wherein the video signal reproducing apparatus is controlled to operate. The control of the output frequency of the control means is
When the external control signal indicates “normal playback”, control is performed so that the video signal input to the video storage means and the decoding means is output at the same frame rate as the input frame rate. 8. A video signal reproducing apparatus according to claim 6 or 7. The control of the output frequency of the control means is
Control in which the external control signal indicates “normal playback” when the external control signal indicates “rewind playback” and the read position of the output video signal in the video storage means catches up with the write position of the input video signal. 7. The video signal reproducing apparatus according to claim 6, wherein the output of the video storage means is controlled so as to be switched to. The input video signal is a signal including an audio signal,
An audio speed conversion means for shortening the reproduction time of the audio signal at a subsequent stage of the video storage means;
The frame display determination means includes
The frame change of the video signal is analyzed, and whether to display each frame on the display device is determined from the analysis result and the audio speed information output from the audio speed converting means. The video signal reproducing apparatus according to 1.

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