JP2007082029A - Video server device and its reproduction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video server device for easily and effectively shortening a time to be spent on a preview operation and its reproduction method. <P>SOLUTION: Skip reproduction is executed with GOP as the minimum unit, and at that time, the reproduction length of one second is secured for both the leading section and last section of a stream raw material. Then, any reproduction section other than the leading section and last section is reproduced in m seconds per n seconds. For example, the reproduction time of about one second per three seconds is secured, and the maximum n-m seconds are secured for any section which is not reproduced. Furthermore, the voice of the same part as the reproduction section of a video is reproduced. The skip reproduction by GOP units is operated from a CM image stream based on the rule. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a video server apparatus installed in a broadcasting station or the like and an image reproduction method thereof.

In a video server device installed in a broadcasting station or the like, a special playback function is provided in order to simplify preview work or the like (see, for example, Patent Document 1). If the double speed reproduction function described in this document is used, the time required for the preview work can be shortened as compared with the reproduction in real time. However, it has been pointed out that audio is often distorted and difficult to hear. This is a problem particularly when previewing commercial videos, and some kind of countermeasure is desired.
Japanese Patent Laid-Open No. 10-210419

As described above, in the existing technology, when the reproduction time is to be shortened by the special reproduction function, the sound is distorted.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a video server device capable of easily and effectively shortening the time required for preview work and a reproducing method thereof.

  In order to achieve the above object, according to one aspect of the present invention, a moving image stream material in which image units composed of a plurality of frames are compressed and encoded using intraframe encoding and interframe predictive encoding. The video server device for generating the preview video of the semiconductor storage element storing the moving image stream material, and the moving image stored in the semiconductor storage element in response to the preview reproduction request for the moving image stream material There is provided a video server device comprising image generation means for generating image data for preview reproduction by acquiring and arranging the image units from a stream material based on a prescribed rule.

  In particular, in the present invention, the image generation means acquires an image unit of at least 1 second from the start portion and the end portion of the moving image stream material, and in every portion other than the start portion and the end portion of the moving image stream material, An image unit of m seconds (m <n) is acquired.

  By taking such a means, a preview image in which a plurality of image units are arranged in order in a thin slice is generated. As a result, since several image units are thinned out, the entire reproduction time can be shortened. Moreover, since each image unit is reproduced for the length of time (for example, every second), the sound is not distorted. Furthermore, an image of at least 1 second is arranged at the start and end portions of the preview image. As a result, the present invention can be used particularly favorably for previewing commercial videos.

  According to the present invention, it is possible to provide a video server device capable of easily and effectively shortening the time required for preview work and a reproducing method thereof.

  FIG. 1 is a functional block diagram showing a video server 11 according to an embodiment of the present invention. The video server 11 is used to create a preview image of a commercial (CM) video at a broadcasting station, for example. A plurality of CM images are stored in the large-capacity memory 12 as a CM image stream compressed and encoded by MPEG2.

  The video server 11 is realized by a computer, and includes a CPU 101, a system controller 102, a memory 103, a network interface unit 104, an encoder interface unit 105, and a plurality of decoder interface units 107 and 108 as shown in the figure.

  The CPU 101 is a processor that controls the operation of the video server 11 and executes an operating system and a preview image creation program loaded in the memory 103. The preview image creation program is a program for creating a preview image of a CM image stream.

  A system controller 102 is a bridge device that connects a processor bus of the CPU 101 and a system bus 100 such as a PCI bus, and a memory controller that controls the memory 103 is also incorporated therein. The network interface unit 104 is a communication device that performs communication with the network 10 such as a LAN, and performs communication with the operation terminal 16 on the network 10. The operation terminal 16 transmits a CM image stream accumulation request and reproduction request (normal reproduction request, skip reproduction request) to the video server 11. The skip reproduction request is transmitted from the operation terminal 16 to the video server 11 as necessary.

  The encoder interface unit 105 communicates with the MPEG2 encoder 13 and receives a compressed video stream from the MPEG2 encoder 13. The MPEG2 encoder 13 generates a compression-encoded moving image stream (MPEG2 stream) by compressing and encoding moving image data output from, for example, a VTR using an MPEG2 moving image compression encoding method. In the MPEG2 moving image compression coding system, intraframe coding (intra coding) and interframe prediction coding (intercoding) are used in combination. As described above, the compression-coded moving image stream includes three types of frames: an I picture obtained by intra coding and a P picture and a B picture obtained by inter coding.

  The decoder interface units 107 and 108 are used as transmission channels for moving picture streams, and MPEG2 decoders 14 and 15 are connected to the decoder interface units 107 and 108, respectively. Each of the decoder interface units 107 and 108 is composed of, for example, a SCSI interface.

  Each of the MPEG2 decoders 14 and 15 decodes a compression-coded moving image stream (MPEG2 stream). Each of the MPEG2 decoders 14 and 15 normally executes a process of decoding, reproducing and outputting each frame in the moving picture stream according to the timing specified by the time stamp information embedded in the MPEG2 moving picture stream ( (Hereinafter referred to as the normal mode), each frame included in the moving picture stream can be sequentially decoded and reproduced and output (hereinafter referred to as push mode) regardless of the time stamp information.

  In MPEG2, as time stamp information, for example, PTS (handles display timing), DTS (handles timing for decoding), PCR (represents the time position of a packet in which PCR is embedded in a stream), etc. Is stipulated. These time stamp information is used for reproducing a moving image stream sent from the video server 11 in real time. In the push mode, each of the MPEG2 decoders 14 and 15 performs a decoding operation ignoring the time stamp information (sequentially decodes and reproduces a stream sent by the push type from the video server 11). In this case, each frame included in the moving image stream is sequentially decoded and reproduced and output each time it is received, and video corresponding to the previous frame is continuously output until the next frame is received.

  The moving image data decoded and reproduced and output by each of the MPEG2 decoders 14 and 15 is sent as video data to a program transmission apparatus provided corresponding to each of the MPEG2 decoders 14 and 15. Next, functions provided in the video server 11 for realizing skip reproduction will be described.

FIG. 2 is a conceptual diagram showing a first example of preview image creation. In the following figure, each square represents a minimum unit of an image stream, and a shaded portion is a portion to be reproduced. This minimum image unit is called GOP (Group of Picture) in the MPEG standard and has a reproduction time of 0.5 seconds. In this embodiment, the skip operation is performed in GOP units. In the present embodiment, the following rules are applied when creating a moving image stream for preview reproduction.
(1) The beginning and end of the material must be played for at least 1 second.
(2) The playback part in the middle is played back for m seconds per n seconds. (M <n)
(3) The portion not to be reproduced is a maximum of nm seconds.
(4) Audio is played back at the same part as the video playback part.
FIG. 2 shows a case where a material whose material seconds is 3 (N + 1) seconds (N is an integer equal to or greater than 0) is skip-reproduced. (B) and (c) show the case where the reproduction start position is not the head of the GOP. In FIG. 2A, skip playback is started after a GOP one second after the IN point that is the head position is played. In the skip playback, a pattern of 2 GOP playback → 4 GOP skip → 2 GOP playback →... Is repeated (repeated part). The last playback portion is also played back in GOP units, starting from the GOP start position one second before the OUT point. And the extra length part for 1 GOP remains. 2B and 2C, since the IN point and the OUT point (end point) are set in the middle of the GOP, the start portion becomes longer than 1 second.

  FIG. 3 shows a case where a material whose material seconds is 3 (N + 1) +1 second (N is an integer of 0 or more) is skip-played, and (a) shows a case where the playback start position is the head of the GOP. , (B), (c) show a case where the reproduction start position is not the head of the GOP. In FIG. 3A, after the GOP one second after the IN point that is the head position is reproduced, skip reproduction is started. 3B and 3C, since the IN point and the OUT point (end point) are set in the middle of the GOP, the start portion becomes longer than 1 second.

  FIG. 4 shows a case where a material whose material seconds is 3 (N + 1) +2 seconds (N is an integer of 0 or more) is skip-reproduced, and (a) shows a case where the reproduction start position is the head of the GOP. , (B), (c) show a case where the reproduction start position is not the head of the GOP. In FIG. 4A, after the GOP one second after the IN point that is the head position is reproduced, skip reproduction is started. 4B and 4C, since the IN point and OUT point (end point) are set in the middle of the GOP, the start portion becomes longer than 1 second.

FIG. 5 is a diagram showing a case where a material whose material seconds is 3 seconds is skip-played. In order to maintain a period of at least 1 second at the beginning and the last part of the material, 2 GOPs are required for both parts, and the skip reproduction time is 2.5 seconds in total.
FIG. 6 is a diagram showing a case where a material whose material seconds is 4 seconds is skip-played. In order to maintain a period of at least 1 second at the beginning and the last part of the material, 2 GOPs are required for both parts, and the skip reproduction time is 2.5 seconds in total.
FIG. 7 is a diagram illustrating a case where a material whose material seconds is 15 seconds is skip-played. In order to maintain a period of at least 1 second at the beginning and last part of the material, 2 GOPs are required for both parts. The maximum skip interval is 2 seconds (4 GOP), and the skip playback time is 6.5 seconds in total. As described above, in this embodiment, n = 3 and m = 1, and a playback portion in the middle is played back for 1 second per 3 seconds, and a portion not played back is 2 seconds at maximum.

FIG. 8 is a diagram showing a case of skipping playback of a material whose material seconds is 3 seconds (actual material length is 4 seconds) for each position of the IN point. That is, the case where it overlaps the head of the IN point GOP is compared with the case where it does not overlap. In either case, the playback time is 2.5 seconds.
FIG. 9 is a diagram showing a case where a material whose material seconds is 4 seconds (the actual material length is 5 seconds) is skip-reproduced in comparison with each position of the IN point. In either case, the playback time is 2.5 seconds.
FIG. 10 is a diagram illustrating a case where a material whose material seconds is 5 seconds (actual material length is 6 seconds) is skip-reproduced in comparison with each position of the IN point. In either case, the playback time is 3 seconds.
FIG. 11 is a diagram showing a case where a material having a material number of seconds of 6 seconds (actual material length is 7 seconds) is skip-reproduced for each position of the IN point. In either case, the playback time is 3.5 seconds.
FIG. 12 is a diagram showing a case where a material whose material seconds is 7 seconds (actual material length is 8 seconds) is skip-reproduced in comparison with each position of the IN point. In either case, the playback time is 3.5 seconds.

  FIG. 13A is a diagram showing a case where a material whose material seconds is 8 seconds (actual material length is 9 seconds) is skip-reproduced in comparison with each IN point position. In either case, the playback time is 4 seconds. FIG. 13B is a diagram showing a case where a material whose material seconds is 15 seconds (actual material length is 16 seconds) is skip-reproduced in comparison with each position of the IN point. In either case, the playback time is 6.5 seconds, which is less than half the material length. FIG. 13C is a diagram showing a case where a material whose material seconds is 30 seconds (the actual material length is 31 seconds) is skip-reproduced for each IN point position. In any case, the reproduction time is 11.5 seconds, which is half or less of the material length.

The playback time is generally determined as follows:
Playback time = Int ((Playback material length-Start-end playback time) / (Skip playback time + Skip interval)) + Start-end playback time * Start-end playback time = Skip playback time + Skip playback time + 0.5 (seconds)
Here, Int () is a function that returns an integer part in parentheses.

  As described above, in this embodiment, skip playback is executed with GOP as the minimum unit, and at that time, a playback length of 1 second is ensured in both the head portion and the last portion of the stream material. Then, in the reproduction part other than the head part and the last part, reproduction is performed for m seconds per n seconds. For example, a playback time of about 1 second per 3 seconds is ensured, and a portion not played back is set to a maximum of nm seconds. Furthermore, the sound at the same location as the playback portion of the video is played back. Under such rules, skip reproduction is performed in GOP units from the CM image stream. Since it did in this way, it becomes possible to provide the video server apparatus which can shorten the time concerning preview work easily and effectively, and its reproducing method.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment.

The functional block diagram which shows the video server 11 which concerns on one Embodiment of this invention. The conceptual diagram which shows the 1st example of preview image preparation. The conceptual diagram which shows the 2nd example of preview image preparation. The conceptual diagram which shows the 3rd example of preview image preparation. The conceptual diagram which shows the 4th example of preview image preparation. The conceptual diagram which shows the 5th example of preview image preparation. The conceptual diagram which shows the 6th example of preview image preparation. The conceptual diagram which shows the 7th example of preview image preparation. The conceptual diagram which shows the 8th example of preview image preparation. The conceptual diagram which shows the 9th example of preview image preparation. The conceptual diagram which shows the 10th example of preview image preparation. The conceptual diagram which shows the 11th example of preview image preparation. The conceptual diagram which shows the 12th example of preview image preparation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Video server, 12 ... Mass memory, 13 ... Encoder, 14, 15 ... Decoder, 16 ... Operation terminal, 101 ... CPU, 103 ... Memory, 105 ... Encoder interface unit, 106 ... Disk interface unit, 107, 108 ... Decoder interface unit

Claims (4)

A video server device that generates a preview image of a moving image stream material that is compressed and encoded using intra-frame coding and inter-frame prediction coding, and in which image units composed of a plurality of frames are arranged,
A semiconductor memory element for storing the moving image stream material;
In response to a preview reproduction request for the moving image stream material, image data for preview reproduction is obtained by obtaining and arranging the image units from the moving image stream material stored in the semiconductor memory element based on a prescribed rule. And a video server device. The image generating means includes
Obtaining at least one second image unit from the start and end of the video stream material;
2. The video server device according to claim 1, wherein an image unit of m seconds (m <n) per n seconds is acquired in a portion other than a start portion and an end portion of the moving image stream material. A reproduction method in a video server device that generates a preview image of a moving image stream material that is compression-encoded using intra-frame coding and inter-frame prediction coding, and in which image units composed of a plurality of frames are arranged,
Storing the moving image stream material in a semiconductor storage element;
In response to a preview reproduction request for the moving image stream material, an acquisition step of acquiring the image unit from a moving image stream material stored in the semiconductor storage element based on a prescribed rule;
And a generating step of generating a moving image stream for preview reproduction by arranging the acquired image units in time order. The obtaining step includes
Obtaining at least one second image unit from the start and end of the video stream material;
4. The reproduction method according to claim 3, wherein an image unit of m seconds (m <n) per n seconds is acquired in a portion other than a start portion and an end portion of the moving image stream material.

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