JP2005109986A - Picture reproducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce at a high speed a coded picture as a moving picture with visually smooth movements. <P>SOLUTION: An I picture and two P pictures following the I picture are reproduced at a higher speed than normal reproduction speed. The above process is performed in order for each GOP. In this way, a moving picture with smooth movements is displayed for a certain period from the start of fast-forwarded reproduction, then a still image is displayed for a certain period and then a moving picture is displayed again for a next certain period. By this means, reproduction of a moving picture and reproduction of a still picture is continuously repeated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for reproducing an image encoded by a predictive encoding method such as MPEG (Moving Picture Image Coding Experts Group), and in particular, fast-forward so that the reproduced image looks more smooth. The present invention relates to a technique for playing back or rewinding.

  One of well-known image data compression techniques is the Moving Picture Image Coding Experts Group (MPEG) system. For example, many background images of lyrics displayed on a karaoke apparatus are encoded by this MPEG method (see, for example, Patent Document 1). In this MPEG system, a concept called GOP (Group of Pictures) is adopted in which a large number of pictures (screens) are grouped into a predetermined number, and the pictures are read and reproduced in units of groups.

  This GOP is composed of three types of pictures: an I picture, a P picture, and a B picture. Among these pictures, the I picture is generated by intra-frame coding, so that it can be decoded into one image using only the data of the I picture itself. Therefore, the I picture is generally called an independent picture. On the other hand, the P picture and the B picture are non-independent pictures and cannot be reproduced only by the data of the P picture itself or the B picture itself. Specifically, the P picture is data obtained by encoding the difference from the previous I picture or P picture by inter-frame forward predictive encoding, so that these other pictures are necessary for decoding. It is. In addition, the B picture is data obtained by encoding the difference from the forward I picture or P picture and the difference from the backward I picture or P picture by inter-frame bi-directional predictive coding. Sometimes these other pictures are needed.

  Incidentally, an apparatus for reproducing an image generally has a function of performing fast forward reproduction or rewind reproduction of an image. For example, Patent Document 2 discloses that when an image is fast-forwarded or rewinded based on image data encoded by the MPEG system (hereinafter referred to as MPEG-encoded), only an I picture is used. It has been proposed to decode and display. The reason why only the I picture is displayed in this way is that in order to display a P picture or a B picture, it is necessary to decode up to other pictures as described above, and such decoding processing is fast-forwarded or rewinded. This is because it is difficult to perform in a short time during high-speed playback.

  Here, FIG. 6 shows the display timing of each picture when played back at a normal playback speed (upper part of FIG. 6), and the display timing of each picture when played back at a playback speed four times faster than normal ( FIG. 6 is a diagram illustrating a lower stage. In FIG. 6, “I” indicates an I picture, “P” indicates a P picture, “B” indicates a B picture, and subscripts “1”, “2”, “3”,. Represents different pictures (this notation is the same in the following description). During normal playback, as shown in the upper part of FIG. 6, all pictures are displayed one by one in a predetermined order, such as “I1” → “B11” → “B12” → “P11” →. It has become so.

  On the other hand, at the time of fast-forward playback, as shown in the lower part of FIG. 6, every other I picture jumps to 0, such as “I1” → “I3” → “I5” → “I7” →. .It is displayed at intervals of 25 seconds. In this case, for example, since “I1” is displayed as a still image for 0.25 seconds after “I1” is displayed, “I3”, which is the next picture, is suddenly displayed. For the viewer who sees the playback image, it looks like a jerky and unnatural movement like frame advance.

JP 2000-99044 A Japanese Patent Publication No. 6-28446

  The present invention has been made to solve such a problem, and an object of the present invention is to reproduce an encoded picture as a moving image having a visually smooth motion at high speed.

  According to the present invention, it is possible to realize high-speed reproduction so that an image looks visually smooth.

In order to solve the above-described problem, the present invention provides encoded data obtained by intraframe encoding using only information of a picture to be encoded among a plurality of pictures constituting a moving image, and an encoding target. Decodes encoded data obtained by interframe coding using information of a certain picture and information of other pictures, and displays each picture obtained by decoding on the display means in each original order and generation time interval Normal reproduction means for performing the reproduction, and all or some of the plurality of pictures constituting the moving image among the pictures that are the targets of intra-frame coding are set as independent pictures to be reproduced, One or more subsequent pictures are set as non-independent pictures to be reproduced, and each independent picture to be reproduced and one or more pictures following the independent picture are reproduced. High-speed playback that repeats the process of decoding the encoded data of the non-independent picture to be played and displaying the picture obtained by decoding on the display means at a time interval shorter than the original occurrence time interval of each independent picture to be played And an image reproducing apparatus.
According to this image reproducing apparatus, when a moving image is reproduced at high speed, one or more non-independent pictures following the independent picture are displayed on the display means in addition to the independent picture. The image can be reproduced.

  As one aspect of high-speed playback, for example, when fast-forward playback of a moving image is performed, the high-speed playback means performs the last playback target non-playing among one or more playback target non-independent pictures following one playback target independent picture. After the independent picture is displayed on the display unit, the last reproduction target non-independent picture may be displayed on the display unit until the next reproduction target independent picture is displayed on the display unit.

  On the other hand, when performing rewind playback of a moving image, the high-speed playback means performs an order reverse to the original generation order of one or more playback target non-independent pictures following one playback target independent picture. Until the last one of the reproduction target non-independent pictures following the reproduction target independent picture preceding the reproduction target independent picture is displayed on the display means. What is necessary is just to make it display a picture on the said display means.

When performing these fast-forward playback or rewind playback, the high-speed playback means is the picture to be displayed on the display means at the end of the one playback target independent picture and one or more playback target non-independent pictures subsequent thereto. It is desirable to display each picture except for at the display means at the same time interval as each original generation time interval.
In this way, the image playback device can perform fast forward playback or rewind playback at high speed without displaying a picture at a time interval shorter than the original generation time interval.
The high-speed playback means uses a period in which the display means displays the last one of the one playback target independent picture and one or more playback target non-independent pictures subsequent thereto, and then displays the display You may make it prepare the reproduction object independent picture displayed on a means, and the 1 or several reproduction object non-independent picture which follows this.
In this way, since the next picture display processing is prepared using the period during which the picture is displayed, the processing can proceed efficiently.

In the present invention, not only a coded independent picture but also a plurality of coded non-independent pictures belonging to the same GOP as the independent picture are used for high-speed playback, so that a moving image with smooth motion is obtained. Reproduction is realized. Note that an independent picture is encoded data obtained by intraframe encoding using only information of an independent picture to be encoded, and a non-independent picture is information on an independent picture to be encoded. And encoded data obtained by inter-frame encoding using information of other pictures.
In the following, in order to facilitate understanding of the invention, an example in which a GOP is composed of only an I picture and a P picture will be described as the first embodiment, and then a GOP is composed of an I picture, a P picture, and a B picture. An example will be described as a second embodiment.

(1) 1st Embodiment FIG. 1: is a block diagram which shows the structure of the karaoke system 100 to which the image reproduction apparatus which concerns on 1st Embodiment is applied. The karaoke system 100 is roughly divided into a karaoke device 101 and a remote controller 102. The karaoke apparatus 101 includes a storage unit 10, an infrared receiving unit 20, a control unit 30, a sound source unit 40, a control amplifier 50, an audio data processing unit 60, a speaker 61, a microphone 62, and an MPEG decoder 70. , A VRAM (Video Random Access Memory) 80, a display control unit 90, and a monitor 91. Among these components, the control unit 30, the MPEG decoder 70, and the VRAM 80 function as the image reproducing device 1 according to the present embodiment. Further, the display control unit 90 and the monitor 91 function as a display unit that performs display processing based on an instruction from the image reproduction device 1.

  The storage unit 10 is a large-capacity storage unit such as an optical disk such as a DVD (Digital Versatile Disk) or a magnetic disk such as a hard disk. The storage unit 10 displays music data for playing music (including chorus sound) and displaying lyrics on the monitor 91, and a background image of lyrics when the music is played on the monitor 91. Image data is stored. The music data is MIDI (Musical Instrumental Digital Interface: registered trademark) data, and the image data is MPEG encoded data. The background image includes an individual background image individually corresponding to a specific music piece, a general-purpose background image provided for each genre of music piece, and the like. Since the individual background image is reproduced in synchronization with the corresponding music, the image data and the music data are output in synchronization.

  The remote controller 102 is a means for an operator to give various instructions to the karaoke apparatus 101. The remote controller 102 includes an operation key for an operator to specify a song, fast-forward or rewind a song being played, and an infrared transmitter that transmits an infrared signal corresponding to the operation content of the operator It has. The infrared receiving unit 20 of the karaoke apparatus 101 has a function of receiving and decoding an infrared signal transmitted by the remote controller 102.

  The control unit 30 includes, for example, an arithmetic device such as a CPU (Central Processing Unit) and various memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and the CPU stores a program stored in the ROM. Is executed to control each component of the karaoke apparatus 101. For example, the control unit 30 reads music data for playing a music specified by the operator from the storage unit 10 and supplies the music data to the sound source unit 40 and the audio data processing unit 60. The tone generator 40 generates a musical sound signal based on the music data and supplies it to the control amplifier 50. The audio data processing unit 60 generates a chorus sound signal based on the music data and supplies the chorus sound signal to the control amplifier 50. In addition to the musical tone signal and the chorus sound signal, the control amplifier 50 mixes the singing voice signal supplied from the microphone 62 to give an effect, and outputs it to the speaker 61 for sound emission. .

  In synchronization with such performance processing, the image reproduction device 1 performs background image reproduction processing. Specifically, the control unit 30 reads MPEG-encoded image data from the storage unit 10 and supplies it to the MPEG decoder 70 as a bit stream. The MPEG decoder 70 decodes encoded data of I pictures and P pictures in each GOP included in the supplied bit stream. These decoded pictures are respectively stored in the VRAM 80 by the control unit 30. Then, the control unit 30 sequentially reads out these pictures from the VRAM 80 at an appropriate timing and supplies them to the display control unit 90, and generates a lyrics message based on the music data read from the storage unit 10 to display the pictures. To supply. The display control unit 90 synthesizes a lyric message with a picture as a background image and displays it on the monitor 91.

  Next, an operation when the image reproduction apparatus 1 performs fast-forward reproduction of the background image at a quadruple speed will be described with reference to FIGS. 2 (b) and FIG. 2 (c) have the same time axis, and the starting point (0.0 seconds) is the time when the fast-forward playback of the background image is started. First, FIG. 2A shows a bit stream of MPEG-encoded image data. One GOP is a set of pictures for a playback time of 0.5 seconds. For example, the pictures “I1” and “P1” to “P9” constitute one GOP. Similarly, the pictures “I2” and “ P21 "to" P29 "constitute one GOP. When performing normal reproduction, the image reproduction apparatus 1 decodes the I picture that constitutes the bit stream and all the P pictures that follow the I picture, and the pictures obtained by decoding are decoded in a predetermined original order. In addition, the background image is reproduced by displaying one after another at a predetermined original generation time interval (here, an interval of 0.05 seconds).

  On the other hand, when fast-forward playback is performed, a part of I pictures appearing at regular intervals on the bit stream and a plurality of P pictures following the I pictures are playback targets of the image playback apparatus 1. Specifically, the image reproducing device 1 reproduces only an I picture that appears every other one and two P pictures that follow this I picture. That is, as illustrated in FIG. 2B, the pictures “I1” → “P1” → “P2” → “I3” → “P31” → “P32” →.

  This operation will be described more specifically with reference to FIG. For example, when the picture “Pk-2” is displayed on the monitor 91, the operator operates the remote controller 102 to instruct fast-forward playback. Since this operation instruction is transmitted from the remote controller 102 to the karaoke apparatus 101, the control unit 30 first identifies the GOP that immediately follows the GOP to which the currently displayed picture “Pk-2” belongs. . Next, the control unit 30 reads out pictures (that is, “I 1”, “P 1”, and “P 2”) to be reproduced in the specified GOP from the storage unit 10 (hereinafter, this process is referred to as a read process). Next, the control unit 30 supplies the read pictures I1, P1, and P2 to the MPEG decoder 70, and the MPEG decoder 70 decodes them (hereinafter, this process is referred to as a decoding process). Then, the control unit 30 stores the decoded pictures “I1”, “P1”, and “P2” one by one in the VRAM 80 (hereinafter, this process is referred to as a storage process). The time required to complete these reading process, decoding process, and storage process is a period corresponding to “preparation for fast forward reproduction” shown in FIG. 2C, and subsequently, the process of “fast forward reproduction” is started. That is, the control unit 30 sequentially reads the pictures “I1”, “P1”, and “P2” stored in the VRAM 80, supplies them to the display control unit 90, and displays them on the monitor 91 at intervals of 0.05 seconds ( Hereinafter, this process is referred to as a movie display process).

  The control unit 30 displays the pictures belonging to one GOP as described above, and the last displayed picture (that is, the picture “P2”) among these pictures is the picture to be displayed next (that is, the picture “P2”). It remains displayed as a still image until the picture “I3”) is displayed. The control unit 30 uses the period until it is displayed as a still image (here, 0.1 second), and the display target pictures (that is, “I 2”, “P 21”, and “P 22”) that belong to the next GOP. ) Is displayed. This preparation process corresponds to the above-described read process, decryption process, and storage process. When these preparations are completed, the control unit 30 proceeds to the moving image display process described above, reads the pictures “I 2”, “P 21”, and “P 22” stored in the VRAM 80 in order and supplies them to the display control unit 90. To do. Thereafter, the control unit 30 repeatedly performs the same processing as described above until an instruction to stop fast-forward playback is given by the operator. As described above, since only a part of all the pictures included in the bitstream is displayed by the image reproducing apparatus 1, a moving image is reproduced at a higher speed than the normal reproduction. For example, as can be seen by comparing the display intervals between the pictures “I1” and “I3” in FIGS. 2A and 2B, the display interval between I pictures during fast-forward playback is 1 / It is four. This indicates that fast-forward playback is being performed at 4 × speed.

  As described above, the moving image reproduction and the still image reproduction are repeatedly and continuously performed, so that a visually smoother motion can be expressed in the reproduced image than before. Further, the control unit 30 performs fast-forward playback of the music in synchronization with the fast-forward playback of the background image as described above. Specifically, the control unit 30 moves a pointer indicating the music data reading position in synchronization with the fast-forwarding double speed, and reproduces the music based on the music data read from the position indicated by the pointer. At this time, since the pitch (key) of the music is increased according to the fast-forwarding double speed, if the control unit 30 performs control processing to lower the key as the double speed increases, a natural sound for the singer is obtained. It will sound like a melody of height.

Here, FIG. 3A shows the order in which each of the decoded pictures is stored in the VRAM 80 and the order in which these pictures are read out from the VRAM 80 and displayed when fast-forwarding reproduction is performed. In the case of fast-forward playback, these pictures may be read out and displayed in the same order as the original generation order of each picture. That is, as illustrated in FIG. 3A, the control unit 30 may read the I picture and the two P pictures from the VRAM 80 in the same order as stored in the VRAM 80 and display them on the monitor 91. Since the order stored in the VRAM 80 and the order read from the VRAM 80 are the same as described above, when fast-forward playback is performed at a very high speed, the next P picture is stored after the I picture is stored in the VRAM 80. It is also possible to immediately read out the I picture and display it.
On the other hand, in the case of rewind playback, these pictures are displayed in the reverse order to the original generation order of each picture. Therefore, as shown in FIG. 3B, the control unit 30 waits until the I picture and the two P pictures are all stored in the VRAM 80, and then reads from the last stored P picture.

  Here, FIG. 4 is a diagram for explaining an operation when the image reproduction device 1 rewinds and reproduces the background image at 4 × speed. In FIG. 4, it is assumed that when the picture “P33” is displayed on the monitor 91, the operator operates the remote controller 102 to instruct rewind playback. In response to this, the control unit 30 specifies the GOP to which the currently displayed picture “P33” belongs, and selects the pictures to be reproduced in the specified GOP (that is, “I3”, “P31”, and “P32”). Read from the storage unit 10. Next, the control unit 30 supplies the read pictures “I3”, “P31”, and “P32” to the MPEG decoder 70 and decodes them. Then, the control unit 30 stores the decoded pictures “I31”, “P31”, and “P32” in the VRAM 80. Further, the control unit 30 reads the pictures “I3”, “P31” and “P32” stored in the VRAM 80 in the order of “P32” → “P31” → “I3”, and supplies them to the display control unit 90. It is displayed on the monitor 91 at intervals of 0.05 seconds. Then, after displaying the picture “I3”, the control unit 30 prepares to display the pictures “P2”, “P1”, and “I1” to be displayed next while displaying them as a still image. When ready, display these pictures. Thereafter, the same processing as described above is repeated for every other GOP.

  As described above, according to the first embodiment, since several P pictures are displayed between the I picture and the I picture, the image displayed at the time of fast forward playback or rewind playback has a visually smooth motion. Can show.

(2) Second Embodiment A second embodiment to be described next is an example in which a GOP is composed of an I picture, a P picture, and a B picture. The second embodiment is different from the first embodiment only in the order in which each picture is decoded and stored in the VRAM 80, and the other configurations are the same as those in the first embodiment.

  For example, assuming a bit stream as shown in the upper part of FIG. 6, when the image playback device 1 performs fast-forward playback, first the picture “I1” is decoded and stored in the VRAM 80 as shown in FIG. Next, the picture “P11” is decoded and stored in the VRAM 80, and then the two B pictures (B11 and B12) are sequentially decoded one by one and stored in the VRAM 80. The order in which the picture reproducing apparatus 1 reads and displays these pictures is “I1” → “B11” → “B12”. On the other hand, when the image playback apparatus 1 performs rewind playback, the order in which each picture is decoded and stored in the VRAM 80 is the same as in fast forward playback, as shown in FIG. However, the order in which pictures are read out and displayed is in the order of “B12” → “B11” → “I1” which is the reverse of fast-forward playback.

In the above description, since one independent picture and two non-independent pictures are played back at high speed, the image playback device 1 does not display the picture “P11” in fast-forward playback, but does rewind playback. Then, the picture “I1” was not displayed. However, for example, if one independent picture and three non-independent pictures are played back at a high speed, the image playback apparatus 1 is in the order of “I1” → “B11” → “B12” → “P11” in the case of fast-forward playback. In the case of rewind playback, the display may be in the order of “P11” → “B12” → “B11” → “I1”.
As described above, according to the second embodiment, as in the first embodiment, several B pictures and P pictures are displayed between the I picture and the I picture, so that they are displayed during fast forward playback and rewind playback. The displayed image can appear to be visually smooth.

(3) Modified Examples The embodiment described above is merely an example, and there are various modified examples.
For example, during high-speed playback, several pictures belonging to every other GOP were targeted for display, but this is not a limitation, and some pictures belonging to all GOPs are targeted for display according to the double speed during high-speed playback. Alternatively, several pictures belonging to every second or every third (or more) GOP may be displayed.
Moreover, although the case where one I picture was included in one GOP was illustrated in the embodiment, the present invention is not limited to this, and a plurality of I pictures may be included in one GOP. In this case, all I pictures and several non-independent pictures that follow them may be subject to playback, and every other or every two (or more) I pictures and some non-following pictures. An independent picture may be a reproduction target.
Further, the number of non-independent pictures displayed between the I picture and the I picture is not limited to “two” exemplified in the embodiment. The number may be more or one as long as a series of processing such as reading processing, decoding processing, storage processing, and moving image display processing can be performed during high-speed playback.
In the embodiment, when performing high-speed playback, only the pictures to be displayed are read from the storage unit 10, but not limited to this, all the pictures are read from the storage unit 10, and the display targets are read from the read pictures. The control unit 30 may select and decode only the pictures that become.
Further, at the time of high-speed playback in the embodiment, each picture is displayed at the same 0.05 second interval as the original generation time interval except for the last picture displayed in one GOP. However, the present invention is not limited to this, and these pictures may be displayed at shorter time intervals.
In the embodiment, a picture to be displayed next is prepared using a period in which a picture to be displayed last is displayed in one GOP. However, when the control unit 30 has sufficient parallel processing capability, the moving image display processing for the pictures included in the preceding GOP and the preparation processing for the pictures included in the subsequent GOP may be performed in parallel.
Of course, the image reproducing apparatus according to the present invention is applied to apparatuses other than the karaoke apparatus exemplified in the embodiment.

It is a figure which shows the structure of the karaoke system to which the image reproduction apparatus which concerns on 1st Embodiment of this invention is applied. (A) a bit stream of MPEG-encoded image data; (b) a timing for displaying a picture based on MPEG-encoded image data during fast-forward playback; and (c) an MPEG-encoded image during fast-forward playback. It is a figure which shows the timing which performs various processes with respect to data. It is a figure which shows the order of the process performed with respect to a picture at the time of (a) fast-forward reproduction | regeneration, and (b) the order of the process performed with respect to a picture at the time of rewind reproduction | regeneration. It is a figure which shows the timing which displays a picture based on the image data by which MPEG encoding was carried out at the time of rewind reproduction | regeneration. It is a figure which shows the order of the process performed with respect to a picture at the time of (a) fast-forward reproduction | regeneration, and (b) the order of the process performed with respect to a picture at the time of rewind reproduction | regeneration. FIG. 6 is a diagram illustrating display timing of each picture in normal playback and display timing of each picture in fast-forward playback at 4 × speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Karaoke system, 101 ... Karaoke apparatus, 102 ... Remote controller, 10 ... Memory | storage part, 30 ... Control part, 70 ... MPEG decoder, 80 ... VRAM, 90. ..Display control unit, 91 ... monitor.

Claims (5)

Coding data obtained by intra-frame coding using only information on a picture to be coded among a plurality of pictures constituting a moving picture, information on a picture to be coded and information on other pictures Normal reproduction means for decoding the encoded data obtained by interframe coding to be used, and displaying each picture obtained by decoding on the display means in their original order and generation time interval;
Of all the pictures constituting the moving picture, all or some of the pictures that are the subject of intra-frame coding are set as playback target independent pictures, and one or a plurality of pictures following each playback target independent picture Processing in which a picture is a non-independent picture to be reproduced, each encoded picture of the independent picture to be reproduced and one or more non-independent pictures to be reproduced subsequent thereto are decoded, and the picture obtained by decoding is displayed on the display means High-speed reproduction means for repeating the above at a time interval shorter than the original generation time interval of each reproduction target independent picture.   When performing fast-forward playback of a moving image, the high-speed playback means causes the display means to display the last playback target non-independent picture among one or more playback target non-independent pictures following one playback target independent picture. 2. The image reproducing apparatus according to claim 1, wherein the last reproduction target non-independent picture is displayed on the display unit until the next reproduction target independent picture is displayed on the display unit.   When performing rewind playback of a moving image, the high-speed playback unit displays one or more playback target non-independent pictures subsequent to one playback target independent picture on the display unit in an order reverse to the original generation order. Until the display unit displays the last one of the reproduction target non-independent pictures following the reproduction target independent picture preceding the reproduction target independent picture on the display unit. The image reproduction apparatus according to claim 1 to be displayed.   The high-speed playback means has each original generation time interval for each picture excluding the picture to be displayed last on the display means among the one playback target independent picture and one or more playback target non-independent pictures following the one playback target independent picture. The image reproducing apparatus according to claim 2, wherein the display unit displays the image at the same time interval.   The high-speed playback means uses a period in which the display means displays the last one of the one playback target independent picture and one or more playback target non-independent pictures subsequent thereto, and then causes the display means to The image reproduction device according to any one of claims 2 to 4, wherein a reproduction target independent picture to be displayed and one or more reproduction target non-independent pictures subsequent thereto are prepared.

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