JP2010093614A - Video signal playback apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video signal playback apparatus for playing back only an important scene in a short time without giving a viewer any sense of incompatibility or discomfort with a frame rate change. <P>SOLUTION: An important frame determining means 3 analyzes a video signal, creates and outputs a list of important frames. On the basis of the important frames and request playback speed information inputted by a viewer, an adjusted speed determining means 5 calculates a playback speed and outputs it to an image signal playback speed change means 7 and an audio signal playback speed change means 9. At the image signal playback speed change means 7 and the audio signal playback speed change means 9, portions corresponding to any other portion than the important frames in the video signal are thinned and playback speeds for image signals and audio signals are changed, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a video signal reproducing apparatus that reproduces an input video signal.

  If you watch the video in a short time and play it at a uniformly high frame rate without distinguishing the important and unimportant parts of the video, the movement of the important parts may be unnatural or the audio may be difficult to hear. And viewability deteriorates. Therefore, the important and unimportant parts of the video are discriminated, the important parts are played without a relatively high frame rate, and the unimportant parts are played with a relatively high frame rate. Video playback technology has been devised that allows video to be viewed in a short time while ensuring the viewability of the appropriate part. For example, a technique for detecting a scene change point to determine a scene break, and setting a frame rate for each scene based on the presence / absence of conversation in the scene and the magnitude of image change (see Patent Document 1) There is a technique (see Patent Document 2) in which a person's utterance section and other sections are determined based on a voice signal and set to different frame rates.

Japanese Patent Laying-Open No. 2006-121570 (page 4-6, FIG. 4) JP 2003-309814 A (page 5-6, FIG. 1)

In Patent Documents 1 and 2, since the frame rate is changed during viewing, the viewer feels uncomfortable and uncomfortable. In particular, when the frame rate is frequently changed or when the difference between the frame rates before and after the change is severe, discomfort and discomfort increase. The present invention has been made to solve the above-described problems, and an object of the present invention is to reproduce only important scenes in a short time without changing the frame rate on the way.

In order to achieve the above object, the video signal reproducing apparatus according to the present invention discriminates frames with less information, thins them out, and reproduces the entire video at a desired frame rate.

With the video signal playback apparatus according to the present invention, it is possible to play back only important scenes in a short time without giving the viewer a sense of discomfort or discomfort associated with a change in the frame rate.

Embodiment 1.
Embodiments of the present invention will be described below. In the video signal playback apparatus according to the first embodiment, frames with less information are discriminated, and after thinning them out, the entire video is played back at a desired frame rate, so that a sense of incongruity and discomfort associated with a change in the frame rate can be obtained. Only important scenes can be played in a short time without giving it to the viewer.

  FIG. 1 is a block diagram showing the configuration of the video signal reproducing apparatus according to the first embodiment, FIG. 2 is a block diagram showing the configuration of the important frame determining means 3, and FIG. FIG. 4 is a block diagram showing the configuration of the image signal reproduction speed conversion means 7.

  The operation of the video signal reproduction apparatus according to the first embodiment will be described with reference to FIGS. It is assumed that the video signal input from the video recording medium such as a DVD to the video signal reproducing apparatus is composed of an image signal and an audio signal, and the image signal is composed of a plurality of frames. First, a video signal is input to the video signal storage means 1 and stored. On the other hand, this video signal is also input to the first AV separation means 2, separated into an image signal and an audio signal and output to the important frame determination means 3.

  The important frame determination means 3 shown in FIG. 2 to which the image signal and the audio signal are input performs the following processing. First, the scene change detection unit 31 detects a scene change point from the image signal output from the first AV separation unit 2 by a detection method described later, and inputs it to the important frame determination unit 33. On the other hand, the silence detection means 32 detects a section where the volume level is smaller than a predetermined threshold from the audio signal output from the first AV separation means 2 and inputs it to the important frame determination means 33 as a silence section.

  The important frame determination unit 33 uses the determination method described later to determine a frame with less information related to the content based on the scene change point output from the scene change detection unit 31 and the silence section output from the silence detection unit 32. The output frame and the remaining frame are determined as important frames, and an important frame list which is a list of frame numbers of important frames is created. Frames determined as non-output frames are thinned out later. Further, the important frame determining means 3 calculates a playback speed (first playback speed) when only important frames are played back at a normal frame rate. Therefore, the first reproduction speed is a value of 1.0 times or higher. The important frame list and the first reproduction speed are output to the analysis information storage unit 4.

  The analysis information storage unit 4 stores the important frame list and the first reproduction speed input from the important frame determination unit 3.

At this time, the video signal storage means 1 stores the video signal, and the analysis information storage means 4 stores the important frame list and the first reproduction speed.

  Next, when the adjustment speed determination means 5 receives the required reproduction speed information, it sends a speed inquiry signal to the analysis information storage means 4. Here, the requested playback speed is a playback speed requested by a viewer or the like, and the requested playback speed information is information input by the viewer using, for example, a remote control or an operation button attached to the video signal device. In response to this, the analysis information storage means 4, if the important frame list is sufficiently stored, gives the first reproduction speed to the adjustment speed determination means 5 and the image signal reproduction speed conversion means 7 and the audio signal reproduction. An important frame list is output to the speed conversion means 9 and a control signal is output to the video signal storage means 1. If the important frame list is not sufficiently accumulated, the important frame list is output after waiting for sufficient accumulation. Receiving the input of the first reproduction speed, the adjustment speed determination means 5 divides the reproduction speed requested by the requested reproduction speed information by the first reproduction speed, and calculates the second reproduction speed. In the video signal reproducing apparatus according to the present invention, reproduction speed conversion by thinning out frames to be thinned determined by the important frame determining means 3, and then reproduction speed adjustment performed to satisfy the reproduction speed required by the required reproduction speed information. Performs two-step playback speed conversion. The second playback speed is a value used in the second stage playback speed conversion, and at what speed the image signal after thinning out non-output frames is thinned to satisfy the playback speed required by the required playback speed information. It is a value that indicates whether to play back. The second reproduction speed calculated by the adjustment speed determination means 5 is output to the image signal reproduction speed conversion means 7 and the audio signal reproduction speed conversion means 9.

  On the other hand, the video signal storage unit 1 that has received the control signal outputs the stored video signal to the second AV separation unit 6. The second AV separation means 6 separates the video signal output from the video signal storage means 1 into an image signal and an audio signal, the audio signal is sent to the audio signal reproduction speed conversion means 9, and the image signal is the image signal reproduction speed conversion means. 7 respectively.

  In the audio signal reproduction speed converting means 9 shown in FIG. 3 to which the audio signal has been inputted, the audio thinning means 91 refers to the frame number of the important frame list inputted from the important frame determining means 3, and the second AV separating means Among the audio signals input from 6, the audio signals corresponding to the frames other than the important frame are thinned out and output to the audio pitch changing means 92. The voice pitch changing unit 92 rewrites and changes the voice pitch of the data of the voice signal input from the voice thinning unit 91 so that the second reproduction speed determined by the adjustment speed determining unit 5 is obtained, and changes the pitch. An audio signal is output to the speaker 10. The speaker 10 outputs the audio signal after the reproduction speed conversion input from the audio signal reproduction speed conversion means 9.

  On the other hand, in the image signal reproduction speed converting means 7 shown in FIG. 4 to which the image signal is inputted, the frame decimation means 71 refers to the frame number of the important frame list inputted from the important frame determining means 3, and the second AV Frames other than the important frame are thinned out from the frame of the image signal output from the separating unit 6 and output to the frame rate changing unit 72. The frame rate changing means 72 rewrites and changes the frame rate of the image signal data input from the frame thinning means 71 so that the second reproduction speed output from the adjustment speed determining means 5 is obtained, and changes the frame rate. The changed image signal is output to the display 8. The display 8 displays the image signal after the reproduction speed conversion input from the image signal reproduction speed conversion means 7.

  Next, the operation of the frame rate changing means 72 will be described in detail based on FIG. FIG. 5A shows an example of an image signal output by the frame thinning means 71. The number of frames in this example is 10. FIG. 5B shows an image signal output from the frame rate changing means 72 when the second reproduction speed is 1.0 times or higher. FIG. 5C shows an image signal output from the frame rate changing means 72 when the second reproduction speed is less than 1.0 times.

  When the second reproduction speed output from the adjustment speed determining means 5 is 1.0 times or higher, the frame display interval is shortened. That is, by increasing the frame rate, the playback time is shortened and the playback speed is increased. Conversely, if the second playback speed is less than 1.0 times, the frame display interval is lengthened. In other words, by reducing the frame rate, the playback time is extended and the playback speed is slowed down.

  Next, the important frame determining means 3 shown in FIG. 2 will be described in detail. First, a scene change detection method performed by the scene change detection means 31 will be described. Since the scene change point detected by the scene change detection means 31 is a scene change point, for example, when changing from the scene A to the scene B, the position is the last frame of the scene A or the position of the first frame of the scene B. As a method for detecting this scene change point, for example, there is a method using a change in average luminance of a frame. A scene change point can be detected by detecting a case where the change amount of the average luminance of the entire frame or each block obtained by dividing the frame into a plurality of blocks exceeds a predetermined threshold.

  The silent section detected by the silent detection means 32 may be based on an audio signal corresponding to one frame of the image signal. For example, when the image signal is 29.97 fps, the sound volume level uses the average value of the amplitude of audio data included in 33 msec.

  In addition, the silence detection means 32 may detect a portion where a person is speaking, and may set a portion not speaking as a silence interval in addition to a silence interval where the volume level is equal to or less than a predetermined threshold. For example, BGM-only scenes, especially program opening and ending. Since such scenes are often not connected to the contents, the video signal can be reproduced in a short time without a sense of incongruity. In particular, since the opening and ending scenes of programs often have a long time, the effect of shortening the playback time when thinning out is great. Furthermore, a portion where a talking voice such as applause or laughter is drowned may be a silent section because there is no sound information related to the content. Applause, laughter, and the like can be automatically detected from the audio signal because the volume level is high and the change in volume level is small after a predetermined time. Further, if all parts with low volume levels are thinned out, the beginning and end of words cannot be heard. Therefore, processing that does not set the silent section for several hundred msec before and after the silent section may be performed.

  Note that the silence detection means 32 may analyze the frequency instead of the volume level and define the silence interval by the frequency feature. For example, a section with many high frequency components may be set as a silent section.

  The important frame determination means 33 has a small amount of information related to the contents, and the frame determined to be a non-output frame is, for example, a frame before and after the scene change point and in a silent section. Before and after the scene change is a scene change part, there is often less important information about the content compared to the other parts, and even if the images before and after the scene change point are thinned out, the image after thinning is uncomfortable Does not occur. Since there is no sound information in the silent section, there is little effect on understanding the content even if it is thinned out.

  However, important words are sometimes emitted even before and after the scene change. This is the case where the scene changes regardless of the topic switching. This is often seen in news programs and the like. Specifically, when there are a plurality of performers, the state of the speaker and the listener is shown while switching the camera. In this case, if the sound volume level is greater than a predetermined threshold value, it is possible to view only the necessary information without losing information, even if it is not thinned out even before and after the scene change.

  When the frames before and after the scene change are set as non-output frames, the amount to be thinned out may be adjusted according to the length of the scene change interval. For example, if the interval between scene changes is as short as about 30 frames, and the non-output frames are before and after the scene change, the interval between scene changes after decimation is further shortened, making it difficult to see. cut back.

Further, “parts with little motion” or “overlapping parts” in the video signal may be detected and the parts may be thinned out. Here, the “part with little motion” is a part where the change in the frame of the image signal is small. If this part is thinned out, the video signal can be reproduced in a shorter time. In addition, the “overlapping part” is, for example, a part in which images before CM are duplicated and reproduced in a quiz program or the like, a next notice of the nth episode in the drama recorded in series, and the (n +1) The previous synopsis. If this portion is thinned out, the video signal can be reproduced in a shorter time without repeatedly reproducing the same video.
Further, by detecting a studio scene of a news program and thinning out the scene, a video other than the studio scene may be created in the news program. This makes it possible to make a short video when only the news part is conveyed.

  Note that the non-output frame can be determined by any method that can determine by combining scene change position information, “part with less movement” information, “overlapping part” information, and silence section position information. The method may be used. The same applies to the other embodiments.

  As described above, according to the video signal reproducing apparatus of the first embodiment, the image signal and the audio signal are analyzed, and after specifying and thinning out frames with less information, the frame rate changing unit 72 serves as an image signal reproducing speed adjusting unit. Is used to convert to a desired playback speed, so that only frames that contain a large amount of information and are necessary for understanding the content can be viewed at a desired playback speed without a sense of incongruity.

  In addition, when converting the playback speed, the video signal is first converted into a video signal of only the important part of the thinning, so the image after thinning is information that does not move or sound when the playback speed is slowed down. There is an effect that it is not extended to a small part or a part with little information is not reproduced when the reproduction speed is increased.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. In Embodiment 2, instead of changing the frame rate as in Embodiment 1, thinned frames are added as image playback speed adjusting means for further increasing the playback speed after frame skipping.

  The basic configuration of the video signal reproduction device in the second embodiment is the same as the configuration of the video signal reproduction device in the first embodiment shown in FIG. The difference from the first embodiment is the configuration of the image signal reproduction speed conversion means 7. FIG. 6 is a block diagram showing the configuration of the image signal reproduction speed conversion means 7 in the second embodiment. The image signal reproduction speed conversion means 7 in the second embodiment is the same as the image signal reproduction speed conversion means 7 in the first embodiment shown in FIG. Instead of this, a non-output frame determining means 73 for additionally determining a frame as a non-output frame to be thinned out is provided as an image signal reproduction speed adjusting means.

  Next, the operation of the video signal reproduction apparatus in the second embodiment will be described. The image signal reproduction speed conversion means 7 receives the second reproduction speed from the adjustment speed determination means 5, the important frame list from the analysis information storage means 4, and the image signal from the second AV separation means 6. Up to this point, the process is the same as in the first embodiment. However, the second reproduction speed is 1.0 times or higher. The operation of the image signal reproduction speed conversion means 7 in the third embodiment will be described below with reference to FIG.

  The non-output frame determination means 73 should further thin out the frames in the important frame list output from the analysis information storage means 4 in order to use the image signal as the second reproduction speed output from the adjustment speed determination means 5. A frame to be a non-output frame is additionally determined, and a new important frame list is created.

FIG. 7 is a flowchart showing the operation of the non-output frame determining means 73. FIG. 8 is an explanatory diagram for explaining an example of the operation of the non-output frame of the non-output frame determining means 73, and shows the frames constituting the image signal. A frame indicated by white represents a “non-output frame”, and a frame indicated by diagonal lines represents an “important frame”. FIG. 8A shows an important frame list of frames output by the analysis information storage unit 4. In FIG. 8A, the non-output frames are frames with frame numbers 1 to 4, and the important frames are frames with frame numbers 5 to 16. Hereinafter, the operation of the non-output frame determining means 73 will be described in detail based on FIG. 7 and FIG. First, in S301 of FIG. 7, an important frame in the important frame list is additionally determined as a non-output frame at a predetermined interval so as to become the second playback speed. In the example of FIG. 8, the important frames in the important frame list are the frames of numbers 5 to 16. If the second playback speed is 1.3 times, 1 in 4 frames as shown in FIG. Decide to add a frame as a non-output frame. As a result, the non-output frames are frame numbers 1, 2, 3, 4, 8, 12, and 16. In step S302, the important frame list is updated. As a result, frame numbers 8, 12, and 16 that have newly become non-output frames are deleted from the important frame list. The new important frame list is output to the frame decimation means 71 in S303.

  The non-output frame determining unit 73 re-determines the non-output frame after the important frame determining unit 3 determines a frame with less information. However, the non-output frame determining unit 73 re-determines the non-output frame before thinning the image signal by the frame thinning unit 71. Since it is determined, the thinning-out process is only required once, which is more efficient than thinning out twice.

  The frame decimation unit 71 refers to the frame number of the new important frame list input from the non-output frame determination unit 73, decimates the frame of the image signal input from the second AV separation unit 6, and the image after decimation A signal is input to the display 8.

  The display 8 displays the image signal after the reproduction speed conversion output from the image signal reproduction speed conversion means 7.

  The operation of other components such as the audio signal reproduction speed conversion means 9 is the same as that of the first embodiment.

  As described above, in the first embodiment, the frame rate is changed after the frame is thinned, and the playback speed is adjusted. On the other hand, in the video signal reproducing apparatus of the second embodiment, the frame rate is thinned instead of being changed. Since the playback speed is adjusted by adding frames, there is an effect that playback can be performed at a desired playback speed even when the frame rate cannot be changed.

  Also, high-speed playback in which image signals and audio signals are played back at a high speed makes the motion and sound uncomfortable as the speed increases. In the second embodiment, when the playback speed is converted, the video signal is thinned out to shorten the playback time, and the thinned video signal is played back at a normal frame rate. Therefore, there is an effect that reproduction without a sense of incongruity is possible in a short time.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, in contrast to the case where the frame is further thinned out to increase the reproduction speed as in the second embodiment, the frame is inserted to interpolate the image signal in order to reduce the reproduction speed. Only the scene can be viewed slowly.

  The basic configuration of the video signal reproduction apparatus in the third embodiment is the same as the configuration of the video signal reproduction apparatus in the first embodiment shown in FIG. The difference from the first embodiment is the configuration of the image signal reproduction speed conversion means 7. FIG. 9 is a block diagram showing the configuration of the image signal reproduction speed conversion means 7 in the third embodiment. The image signal reproduction speed conversion means 7 in the third embodiment is the same as the image signal reproduction speed conversion means 7 in the second embodiment shown in FIG. As a means, instead of the non-output frame determination means 73, a frame interpolation means 74 for interpolating by inserting a frame into the image signal is provided.

  Next, the operation of the video signal reproduction apparatus in the third embodiment will be described. As shown in FIG. 1, the image signal reproduction speed conversion means 7 includes the adjustment speed determination means 5 for the second reproduction speed, the analysis information storage means 4 for the important frame list, and the second AV separation means 6 for the image signal. Are the same as in the first embodiment up to the point where each is input. However, the second reproduction speed is less than 1.0 times speed. The operation of the image signal reproduction speed conversion means 7 in the third embodiment will be described below with reference to FIG.

  The frame decimation unit 71 refers to the frame number of the important frame list output from the analysis information storage unit 4, decimates the frame of the image signal output from the second AV separation unit 6, and sets the image signal after decimation to the frame Input to the interpolation means 74.

  FIG. 10 is a flowchart showing the operation of the frame interpolation means 74. FIG. 11 is an explanatory diagram for explaining an example of the operation of the frame interpolation means 74. Hereinafter, the operation of the frame interpolation means 74 will be described with reference to FIGS. FIG. 11A shows an image signal input from the frame thinning means 71. FIG. 11B shows an image signal output from the frame interpolation means 74 when the second reproduction speed is 0.75 times. When the important frame list and the second reproduction speed are input, the frame interpolation unit 74 first determines the frame insertion position in S401 of FIG. In the example of FIG. 11, the second playback speed of FIG. 11A is 0.75 times, that is, the frame numbers 3, 6 at a rate of 1 frame to 3 frames so that the playback time is 1.3 times. , 9 immediately after the frame is set as the insertion position, and frames with frame numbers 3 ′, 6 ′, and 9 ′ are inserted, respectively. In the next S402, an interpolation frame to be inserted is created. Interpolation frames can be created based on image data of frames before and after the insertion position, or by using a copy of any of the frames before and after, so that a sense of incongruity due to interpolation can be suppressed. In this example, the interpolation frames with frame numbers 3 ′, 6 ′, and 9 ′ are duplicates of frames with frame numbers 3, 6, and 9. In step S403, the interpolation frame created at the insertion position determined in step S401 is inserted. In the example of FIG. 11, as shown in FIG. 11B, frames with frame numbers 3 ′, 6 ′, and 9 ′ are inserted after frames with frame numbers 3, 6, and 9, respectively. Thereafter, the interpolated image signal is output from the frame interpolation means 74.

  The interpolated image signal The image signal is displayed on the display 8. The operation of other components is the same as that of the first embodiment.

  In the first embodiment, after the frame is thinned out, the frame rate is changed to adjust the reproduction speed. In the third embodiment, the image signal and the audio signal are analyzed to determine a frame with less information. After thinning out, the frame is interpolated so that it is played back at low speed, so there is little discomfort, and only important scenes can be viewed without feeling uncomfortable without missing or missing important scenes. There is an effect that it is possible.

  The requested playback speed input from the outside can be set freely by the user, so that there is an effect that it can be set according to the user's preference, such as setting to the speed at which he / she is usually speaking.

  Also, because frames are inserted and interpolated to slow down the playback speed, especially when watching videos with utterances that are difficult to hear quickly, or when you want to listen slowly, such as in English conversation, watch scenes with fast movement such as sports. It is effective when you want to.

  Further, since the frame is inserted and interpolated in order to reduce the reproduction speed, there is an effect that reproduction is possible even when the frame rate cannot be changed.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, the second and third embodiments are combined so that both the addition of thinned frames and the interpolation of frames can be performed.

  The basic configuration of the video signal reproducing apparatus in the fourth embodiment is the same as the configuration of the video signal reproducing apparatus in the first embodiment shown in FIG. The difference from the first embodiment is the configuration of the image signal reproduction speed conversion means 7. FIG. 12 is a block diagram showing the configuration of the image signal reproduction speed conversion means 7 in the fourth embodiment. The constituent elements of the image signal reproduction speed converting means 7 in the fourth embodiment are the frame thinning means 71 for thinning out the frames, the non-output frame determining means 73 for additionally determining the thinned frames as in the second embodiment, and the embodiment. 3, frame interpolation means 74 for interpolating frames in the image signal, speed conversion processing switching means 75 for switching the output destination of the second reproduction speed, and analysis information input / output switching for switching the output destination of the important frame list Means 76, image signal input / output switching means 77 for switching the output destination of the image signal.

  Next, the operation of the video signal reproduction apparatus in the fourth embodiment will be described. As shown in FIG. 1, the image signal reproduction speed conversion means 7 is supplied with the second reproduction speed from the adjustment speed determination means 5, the important frame list from the analysis information storage means 4, and the image signal from the second AV separation means 6. Are the same as those in the first embodiment.

  Hereinafter, the operation of the image signal reproduction speed converting means 7 will be described with reference to FIG. The adjustment speed output from the adjustment speed determination means 5 is input to the speed conversion process switching means 75. The speed conversion processing switching means 75 operates differently when the second reproduction speed is 1.0 times or higher and when it is less than 1.0 times.

  When the second playback speed is 1.0 times or higher, the speed conversion process switching means 75 outputs the second playback speed output from the adjustment speed determination means 5 to the non-output frame determination means 73. Further, a control signal for controlling the analysis information input / output switching unit 76 is output so that the important frame list output from the analysis information storage unit 4 is input to the non-output frame determination unit 73, and is output from the frame decimation unit 71. A control signal for controlling the image signal input / output switching means 77 is output so that the received image signal is input to the display 8.

  The analysis information input / output switching unit 76 inputs the important frame list to the non-output frame determining unit 73 under the control of the speed conversion processing switching unit 75. The non-output frame determining unit 73 is configured to execute the second embodiment from the frame in the important frame input from the analysis information input / output switching unit 76 so that the second reproduction speed output from the speed conversion processing switching unit 75 is obtained. The non-output frame is determined by the same method as described above, and the important frame list is updated and sent back. The new important frame list updated in this way is input to the frame thinning means 71.

  The frame decimation unit 71 refers to the frame number of the new important frame list output from the analysis information input / output switching unit 76, and decimates frames other than the important frame of the image signal output from the second AV separation unit 6. . The thinned image signal is output to the image signal input / output switching means 77. The image signal input / output switching unit 77 inputs the image signal output from the frame thinning unit 71 to the display 8 under the control of the speed conversion processing switching unit 75.

  When the second playback speed is 1.0 times or higher, the non-output frame determining means 73 and the frame thinning means 71 are used for the image signal output from the second AV separation means 6 in this way. Converted.

  On the other hand, when the second playback speed is less than 1.0 times speed, the speed conversion processing switching means 75 outputs the second playback speed output from the adjustment speed determining means 5 to the frame interpolation means 74. Further, the control signal for controlling the analysis information input / output switching unit 76 is output so that the important frame output from the analysis information storage unit 4 is input to the frame decimation unit 71, and the image signal output from the frame decimation unit 71 is output. A control signal for controlling the image signal input / output switching unit 77 is output so that the signal is input to the frame interpolation unit 74.

  The analysis information input / output switching unit 76 inputs the important frame list to the frame thinning unit 71 under the control of the speed conversion processing switching unit 75. The frame thinning means 71 refers to the frame number of the important frame list output from the analysis information input / output switching means 76 and thins frames other than the important frame of the image signal output from the second AV separation means 6.

The image signal input / output switching unit 77 inputs the image signal output from the frame decimation unit 71 to the frame interpolation unit 74 in accordance with the control of the speed conversion processing switching unit 75. The frame interpolation means 74 inserts the image signal into the image signal at a predetermined interval by the method described in the third embodiment so that the second reproduction speed outputted from the speed conversion processing switching means 75 is obtained. Interpolate. The interpolated image signal is input to the display 8.

  When the second playback speed is less than 1.0 times, the playback speed of the image signal output from the second AV separation means 6 is converted by the frame thinning means 71 and the frame interpolation means 74 in this way. The

  As described above, the video signal playback apparatus according to Embodiment 4 is configured to adjust the playback speed to a high speed or a low speed according to the second playback speed after specifying and thinning out frames with less information. Therefore, there is an effect that only a frame that has a lot of information and is necessary for understanding the contents can be viewed at a desired reproduction speed without a sense of incompatibility.

  Further, since frames are thinned out in order to increase the reproduction speed, and frames are inserted and interpolated in order to reduce the reproduction speed, there is an effect that reproduction can be performed at a desired reproduction speed even when the frame rate cannot be changed.

  Also, there is an effect that the playback speed can be increased or decreased in one playback device.

  In the first to fourth embodiments, the requested playback speed information input to the adjustment speed determining means 5 may be other information as long as the requested playback speed can be calculated. For example, the required playback time may be used. This is because the required playback speed is calculated by dividing the playback time for playback at 1.0 times speed by the required playback time. Alternatively, it may be information specifying the viewing end time. This is because the required playback time is calculated by subtracting the time when the requested playback speed information is input from the viewing end time. The above calculation process may be performed by the adjustment speed determination means 5.

  In the first to fourth embodiments, other information may be used instead of the important frame list as long as the information can identify the frame to be thinned out. For example, a list of frame numbers of non-output frames (non-output frame list) may be used. As a result, when the number of non-output frames is smaller than the number of important frames, the amount of information that the analysis information storage means 4 must store is reduced. When important frames (non-output frames) are continuous, the frame numbers of the start and end frames of the important frame (non-output frame) may be used instead of the important frame list (non-output frame list). As a result, the amount of information that the analysis information storage means 4 must store is smaller than a list in which the frame numbers of important frames (non-output frames) are listed one by one. According to these methods, the capacity of the memory used as the analysis information storage means 4 can be reduced, and the cost can be reduced.

  In the first to fourth embodiments, the voice pitch changing unit 92 may perform processing so that the pitch does not change when changing the pitch. For example, if the playback speed is 1.0 times or higher, the pitch of the audio signal is increased, but if it is output as it is, a voice with an increased pitch is output, so data processing is performed to lower the pitch so that the pitch does not change. The playback speed can also be changed by changing the bit rate.

  In the first to fourth embodiments, the video signal input to the video signal reproduction device may be a TV signal received from an antenna and demodulated by a tuner. Further, the video signal input to the video signal reproduction device may be composed only of the image signal.

It is a block diagram which shows the structure of the video signal reproduction | regeneration apparatus based on Embodiment 1-4 of this invention. It is a block diagram which shows the structure of the important frame determination means 3 which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the audio | voice signal reproduction speed conversion means 9 which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the image signal reproduction speed conversion means 7 which concerns on Embodiment 1 of this invention. It is explanatory drawing explaining operation | movement of the frame rate change means 72 which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the image signal reproduction speed conversion means 7 concerning Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the non-output frame determination means 73 which concerns on Embodiment 2 of this invention. It is explanatory drawing explaining operation | movement of the non-output frame determination means 73 which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the image signal reproduction speed conversion means 7 concerning Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the frame interpolation means 74 which concerns on Embodiment 3 of this invention. It is explanatory drawing explaining operation | movement of the frame interpolation means 74 which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the image signal reproduction speed conversion means 7 which concerns on Embodiment 4 of this invention.

Explanation of symbols

1 video signal storage means,
2 first AV separation means,
3 Important frame determination means,
4 analysis information storage means,
5 adjustment speed determining means,
6 Second AV separation means,
7 image signal reproduction speed conversion means,
8 display,
9 Voice signal playback speed conversion means,
10 Speaker,
31 Scene change detection means,
32 Silence detection means,
33 important frame determination means,
71 frame thinning means,
72 frame rate changing means,
73 Non-output frame determining means,
74 frame interpolation means,
75 speed conversion processing switching means,
76 Analysis information input / output switching means,
77 Image signal input / output switching means,
91 voice thinning means,
92 Voice pitch changing means

Claims (7)

An important frame determining means for analyzing an input video signal and determining a frame to be thinned and a frame to be thinned;
Frame thinning means for thinning out frames to be thinned determined by the important frame determining means;
Image signal reproduction speed adjusting means for adjusting the reproduction speed of an image signal composed only of frames determined by the important frame determining means, which are necessary to satisfy the reproduction speed required from the outside. A video signal reproducing apparatus provided. The important frame determination means is
Scene change detection means for analyzing the image signal, detecting the position of the scene change and outputting the information;
Silence detection means for analyzing the audio signal, detecting the silent section and outputting the information,
2. An important frame determining unit for determining a frame to be thinned out based on the position information of the scene change output from the scene change detecting unit and the silent section information output from the silence detecting unit. The video signal reproducing device described in 1. The image signal reproduction speed adjusting means is
3. The video signal reproducing device according to claim 1, wherein the video signal reproducing device is a frame rate changing means for changing a frame rate of the image signal. The image signal reproduction speed adjusting means is
The video according to claim 1 or 2, wherein the non-output frame determining means further determines a frame to be thinned in addition to the frame to be thinned determined by the important part determining means and causes the frame thinning means to thin out the frame. Signal reproduction device. The image signal reproduction speed adjusting means is
3. The video signal reproducing apparatus according to claim 1, wherein the video signal reproducing apparatus is a frame interpolating means for interpolating by inserting a frame into an image signal in order to reduce a reproducing speed. The image signal reproduction speed adjusting means is
Non-output frame determining means for additionally determining a frame to be thinned in addition to the frame to be thinned determined by the important frame determining means;
In order to slow down the reproduction speed, it has a frame interpolation means for inserting and interpolating frames at predetermined intervals in the image signal,
2. The method according to claim 1, wherein either the non-output frame determining means or the frame interpolating means is used to adjust the reproduction speed of the image signal according to the reproduction speed required from the outside. 2. The video signal reproducing apparatus according to 2. Audio thinning means for thinning out a portion of the audio signal corresponding to the frame to be thinned determined by the important frame determining means;
The audio pitch changing means for changing the pitch of the audio signal after the thinning by the thinning means in order to satisfy a reproduction speed required from the outside. Video signal playback device.

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