JPH0822061B2 - Video / audio coding data multiplexing device and multiplexing data reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image coding data capable of reading high-speed multiplexed data from a storage medium in a moving image / sound coding and decoding system for storage. The present invention relates to a multiplexing device for voice coded data and a device for reading multiplexed data from a storage medium, and more particularly to a device capable of performing special decoding processing at high speed.

[0002]

2. Description of the Related Art Conventionally, when moving picture coded data and audio coded data are multiplexed for storage media, first, a header is added to a certain unit of image coded data and an image packet is created. To generate. At the same time, a header is added to the voice coded data corresponding to one image coded data unit to generate a voice packet. Next, a header is added to the image packet and the audio packet to generate a multiplexed packet. Here, the unit of packetization is generally a unit corresponding to one frame of image. FIG. 7 is a block diagram of a conventional encoding data multiplexing device in a conventional moving image / audio encoding system for storage media. As shown in FIG. 7, the encoding data multiplexing device includes an image packet generation unit 41 that generates an image packet, an audio packet generation unit 42 that generates an audio packet, and a multiplexing packet that generates a multiplexed packet. It is composed of a generation unit 43.
Further, the multiplexed packet generator 43 comprises a packet combiner 44 and a header adder 45. First, the image packet generator 41 adds a header to the input image coding data for one frame to generate an image packet. Similarly, in the voice packet generator 42,
When the voice coding data for one frame is input, a header is added to this to generate a voice packet. Next, the image packet and the audio packet are separately input to the multiplexing packet generation unit 43. In the multiplexed packet generator 43, the input image packet and audio packet are combined by the packet combining means 44 and transferred to the header adding means 45. The header adding means 45 adds a header to the combined image packet and audio packet to generate a multiplexed packet, which is output to the outside as multiplexed data.

FIG. 8 is a block diagram showing the format of a packet generated by the coded data multiplexer of FIG. First, in the image packet generated by the image packet generator 41 of FIG. 7, a header is added to the image coding data as shown in FIG. Become. This header is an image packet identifier for indicating that this packet is an image packet, and whether or not the image coding data in the packet is intra-frame coded (Intra coded). , An image packet size indicating the size of the packet, and other additional information. Next, the voice packet generated by the voice packet generator 42 of FIG. 7 has a header added to the voice coding data as shown in FIG. 8B, and the right side of the format is the top. Is. This header is composed of a voice packet identifier for indicating that this packet is a voice packet, a voice packet size indicating the size of the packet, and other additional information. Next, in the multiplexed packet generated by the multiplexed packet generator 43 of FIG. 7, as shown in FIG. 8C, a header is added before the image packet and the audio packet, and the right side is the head. is there. This header is composed of a multiplexed packet identifier for indicating that this packet is a multiplexed packet, and other additional information. On the other hand, although not shown, in a system for decoding the multiplexed data recorded on the storage medium, generally, a normal reproduction process for decoding the multiplexed data continuously input along the time axis is performed. In addition, only multiplexed packets (Intra packets) containing intra-frame coded image packets are continuously read from the storage medium and decoded to decode special packets such as picture search or random access. Perform playback processing.

FIG. 9 is a format diagram of multiplexed data described in a conventional storage medium. Also in this case, the right side is the head, and next to the multiplex header, the multiplex data of one frame consisting of the image packet and the audio packet is continuously stored in the medium for a plurality of frames. It When reading Intra packets from storage media,
With respect to the multiplexing data of FIG. 9, a multiplexing packet including an image packet whose intra-frame coding identifier indicates intra-frame coding (Intra) is searched. The storage medium is searched until the above multiplexed packet is found, and the packet is read at the time of detection. When reading Intra packets continuously, the above process is repeated. Regarding multiplexing in such a moving image audio encoding / decoding system for storage media, for example, ISO / IEC-JTC1-DIS-1112 (In
formation technolpgy-Coding of moving pictures
and associated audio for digital storage m
edia up to about 1.5 Mbit / s) or Tomoaki Tanaka, "A study of video storage and transfer device for video handling support" (1991, IEICE Technical Report IE91-
59). By the way, in the decoding system, when performing reproduction processing such as picture search and random access, it is required to decode an image as fast as possible. Therefore, it is necessary to read the multiplexed packet including the Intra packet from the storage medium at high speed.

[0005]

However, in the conventional multiplex packet reading method, since the intra-frame coded identifier of the image packet is searched to find the Intra packet, the storage medium is frequently accessed. Occurs, and the reading speed becomes slow. Therefore, in the conventional system, it is impossible to perform special reproduction processing such as picture search and random access at high speed. As described above, in the conventional multiplexed data coding system, since the multiplexing is not performed in consideration of the reading from the storage medium, there is a problem that the Intra packets cannot be continuously read at high speed. It was An object of the present invention is to solve such conventional problems and provide a video / audio coding data multiplexing device and a multiplexing data reading device capable of reading high-speed Intra packets from a storage medium. Especially.

[0006]

In order to achieve the above object, a video / audio coded data multiplexing apparatus of the present invention includes (a) an image packet containing image coded data and voice coded data. In a data multiplexing device for multiplexing voice packets for storage media, means (6) for calculating the size of the multiplexed packet using the image packet and the voice packet, and the image packet and the voice packet Means to combine into multiplexed packets
(4), a multiplex buffer (11) for storing the multiplex packet, a multiplex buffer control means (12) for controlling the multiplex buffer, and a current multiplex when the multiplex packets are continuously created. Multiplexed packet that contains one past frame of encoded image data from the encoded packet
1 to the backward Intra packet offset memory (9) that stores the offset value up to
Image data encoded in the future
A front Intra packet offset memory (10) for storing the offset value Murrell to multiplexed packet, the multi
A backward Intra packet offset calculating unit (7) for calculating a backward Intra packet value using the multiplexed packet size calculated by the duplicated packet size calculating unit and the contents of the backward Intra packet offset memory, and the multiplexed packet size. And a forward Intra packet offset calculation means (8) for calculating a forward Intra packet value using the contents of the forward Intra packet offset memory.
And above and above Intra packet offset
The offset value calculated by the calculation means is used to multiplex the header
And means (5) for creating a header by including the header . Further, the multiplexed data reading device of the present invention is: (b) a multiplexed data reading device for continuously reading Intra packets from the multiplexed data multiplexed by the video / audio coded data multiplexing device. Means for reading multiplexed packet (32)
A multiplex header analysis means (33) for obtaining the forward and backward Intra packet offsets from the read multiplexed header of the multiplexed packet, and the forward and backward Intra.
It is also characterized by including a read position moving means (34) for moving the read position to the beginning of the preceding and following Intra packets by using the packet offset.

[0007]

According to the present invention, when the image coded packet and the audio coded packet are multiplexed, the offset value from the current multiplexed packet to the past (backward) Intra packet and the current multiplexed packet To the next (forward) Intra packet are calculated, and these offset values are included in the multiplexing header. Also,
From the multiplexed data recorded on the storage medium, I
When continuously reading ntra packets, the offset value is acquired from the multiplex header and the Int that should be read next
ra Skip to the beginning of the packet. In this way, it is possible to read Intra packets continuously and at high speed by calculating the offsets to the forward and backward Intra packets at the time of multiplexing and using the offsets when reading from the storage medium.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of a video / audio coding data multiplexing apparatus showing an embodiment of the present invention. In FIG.
Reference numeral 1 is an image packet generation unit that generates an image packet, 2 is a voice packet generation unit that generates a voice packet, and 3 is a multiplexing packet generation unit that generates a multiplexing packet. Also, in the multiplexed packet generator 3, 4 is a packet combining means for combining an image packet and an audio packet, 5 is a header creating means for creating a multiplexed header, and 6 is a multiplex for calculating the size of the multiplexed packet. Packet size calculating means, 7 is a backward Intra packet offset calculating means for calculating a backward Intra packet offset value, 8 is a forward Intra packet offset calculating means for calculating a forward Intra packet offset value, and 9 is a backward Intra packet offset value. Backward Intra packet offset memory, 10 is a forward Intra packet offset memory that stores a forward Intra packet offset value, 11 is a multiplexing buffer that stores a multiplexed packet, and 12 is a multiplexing buffer control unit that controls the multiplexing buffer 11. . As a result, the video / audio multiplexer of the present embodiment performs the multiplexing process of the video coded data and the voice coded data as follows. First, when the image coding data is input to the image packet generation unit 1, the image packet generation unit 1 receives the input 1
A header is added to the image coding data for the frame to generate an image packet. Similarly, when voice coded data is input to the voice packet generator 2, the voice packet generator 2 adds a header to the input voice encoded data for one frame. Generate a voice packet. Then, the generated image packet and voice packet are input to the multiplexing packet generation unit 3.

FIG. 2 is a format diagram of a multiplexed packet generated by the coded data multiplexer of FIG. 1, and FIG. 3 is a front Intra packet offset value and a rear Intra packet offset of the present invention. It is a figure which shows the concept of a value. As shown in FIG. 2, the header of the multiplexed packet in this embodiment includes a multiplexed packet identifier for indicating that the packet is a multiplexed packet, a forward Intra packet offset value, and a backward Intra packet offset value. ,
It is composed of other additional information. As described above, the reason why the forward Intra packet offset value and the forward Intra packet offset value are added to the header of the multiplexed packet is that the offset values up to the past and future Intra packets are used to perform the multiplexing recorded in the storage medium. Conversion data
This is because the Intra packet is read from the data. That is, as shown in FIG. 3, 1 of the current Intra packet
The offset value up to the future Intra packet and the offset value up to the previous Intra packet of the current Intra packet are described in the header of the multiplexed packet. Therefore, these values are used to speed up the speed of the Intra packet. Can be detected. Specifically, when reading Intra packets consecutively from the multiplexed data recorded in the forward storage medium, first, the offset value is acquired from the multiplexed header, and the beginning of the Intra packet to be read next. You can skip to. As a result, Intra packets can be continuously read from the storage medium at high speed.

4 and 5 are flowcharts of the processing operation of the multiplexed packet generator in FIG. First,
After initializing the backward Intra packet offset memory 9 and the forward Intra packet offset memory 10 (step 201), the multiplexed packet size calculation means 6 calculates the size of the multiplexed packet from the input image packet and voice packet ( Step 202). This multiplexed packet size is input to the header addition means 5, the backward Intra packet offset calculation means 7, and the forward Intra packet offset calculation means 8, respectively. The backward Intra packet offset calculation means 7 adds the input packet size and the contents of the backward Intra packet offset memory 9 and stores the addition result in the backward Intra packet offset memory 9 (step 203). Forward Intra
The packet offset calculating means 8 sets the content of the forward Intra packet offset memory 10 to 0 when the encoded data in the image packet is Intra (step 20).
4) If it is not Intra, the input packet size and the contents of the forward Intra packet offset memory 10 are added, and the addition result is stored in the forward Intra packet offset memory 10 (step 205). The backward Intra packet offset memory 9 and the forward Intra
The contents of the packet offset memory 10 are set to 0 by the initialization processing when the processing of the device is started.

Next, the packet combining means 4 of FIG. 1 combines the image packet and the voice packet (step 20).
6) and input it to the header adding means 5. The header adding means 5 reads the backward Intra packet offset value from the backward Intra packet offset memory 9 (step 207) and creates a multiplexed header including this value (step 208). The created multiplexed packet is Intra
If it is a packet, the header adding means 5 rewrites the contents of the backward Intra packet offset memory 9 with the multiplexed packet size value input from the multiplexed packet size calculation means 6 (step 209). When the created multiplexed packet is an Intra packet, the multiplexing buffer control means 12 further reads the forward Intra packet offset value from the forward Intra packet offset memory 10,
The value is set as the forward Intra packet offset value in the header of the multiplexed packet stored at the beginning in the multiplexing buffer memory 11 (step 210). Next, after all the multiplexed packets in the multiplex buffer memory 11 are discharged (step 211), the multiplex packet output from the header adding means 5 is stored at the head of the multiplex buffer memory 11 (step 212). . On the other hand, when the created multiplexed packet is not Intra, the buffer control means 12 adds the created multiplexed packet to the tail of the data stored in the multiplex buffer memory 11 (step 213). By repeating the above processing, multiplexed data is created.

Next, a method of reading the multiplexed data generated by the coded data multiplexing apparatus of FIG. 1 from the storage medium will be described. FIG. 6 is a block diagram of a multiplexed data reading apparatus showing an embodiment of the present invention. In a moving picture / audio decoding system for storage media, an Intra from the storage media is used by using a multiplexed data reading device.
Continuous reading of data is performed. In FIG. 6, 31 is a multiplexing data reading unit for reading the multiplexing data from the storage medium, 32 is a multiplexing packet acquisition means for obtaining the multiplexing packet from the read multiplexing data, and 33 is the read multiplexing. Forward and backward I from the multiplexed header of the encrypted packet
Multiplexing header analysis means for obtaining the ntra packet offset, and 34 is a read position moving means for moving the read position to the beginning of the preceding and following Intra packets using the forward or backward Intra packet offset. The operation of FIG. 6 will be described below. First, the multiplexed packet reading means 32
As a result, one Intra packet is acquired from the multiplexed data written in the storage medium, and the multiplexed header is transferred to the multiplexed header analysis means 33. The multiplex header analysis means 33 analyzes the multiplex header and forwards and backwards I
Get the ntra packet offset. Then, when the next Intra packet to be read next is in the past,
By inputting the backward Intra packet offset value from the multiplex header analysis means 33 to the read position moving means 34, the read position moving means 34 moves the read position of the storage medium backward by that value. Further, when the Intra packet to be read next is a future one, by inputting the forward Intra packet offset value from the multiplex header analysis means 33 to the read position moving means 34, the read position moving means 34 stores the value of the value. Only move the reading position of the storage media forward. By repeating this process, Intra packets can be continuously read.

As described above, in the method for multiplexing the image coding data and the audio coding data in this embodiment, the offset values to the past and future Intra packets are calculated at the time of multiplexing. And add it to the multiplexing header.
In the multiplexed data reading method of this embodiment, the offset values up to the past and future Intra packets described in the multiplexed header are used to record the multiplexed data recorded in the storage medium. The Intra packet is read from. This makes it possible to read Intra packets continuously and at high speed from the storage medium. The format of the multiplexed packet generated according to the present invention is not limited to the format shown in FIG. 2 and may have another format configuration.

[0014]

As described above, according to the present invention,
When multiplexing image coded data and audio coded data, the multiplexed data considering reading from the storage medium
Data can be created, and when decrypting,
Since Intra packets can be continuously read at high speed from the storage medium, special reproduction processing such as picture search and random access can be performed at high speed in the decoding system.

[Brief description of drawings]

FIG. 1 is a block diagram of a video / audio coding data multiplexing apparatus showing an embodiment of the present invention.

FIG. 2 is a format configuration diagram of a multiplexed packet generated in FIG.

FIG. 3 is a diagram showing the concept of forward and backward Intra packet offset values calculated by a multiplexing packet generation unit in FIG.

FIG. 4 is a part of an operation flowchart of a multiplexed packet generation unit in FIG.

FIG. 5 is another part of the operation flow chart of the multiplexing packet generator.

FIG. 6 is a block diagram of a multiplexed data reading device showing an embodiment of the present invention.

FIG. 7 is a block diagram of a conventional video / audio coding data multiplexing device.

FIG. 8 is a format configuration diagram of a packet generated by the device in FIG.

FIG. 9 is a format configuration diagram of multiplexed data generated by the device in FIG.

[Explanation of symbols]

 1 Image Packet Generator 2 Voice Packet Generator 3 Multiplexed Packet Generator 4 Packet Combiner 5 Header Adder 6 Multiplexed Packet Size Calculator 7 Rear Intra Packet Offset Calculator 8 Front Intra Packet Offset Calculator 9 Rear Intra Packet Offset Memory 10 Forward Intra packet offset memory 11 Multiplexing buffer memory 12 Multiplexing buffer control means 31 Multiplexing data reading section 32 Multiplexing packet acquisition means 33 Multiplexing header analyzing means 34 Reading position moving means 41 Image packet generating section 42 Audio Packet generating unit 43 Multiplexing packet generating unit 44 Packet combining unit 45 Header adding unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04L 12/56 H04N 7/15

Claims (2)

[Claims] 1. A data multiplexing device for multiplexing an image packet containing image coded data and a voice packet containing voice coded data for a storage medium, wherein the image packet and the voice packet are used. Means for calculating the size of the multiplexed packet and combining the image packet and the audio packet for multiplexing
A packetizing means, a multiplexing buffer for storing the multiplexed packet, a multiplexing buffer control means for controlling the multiplexing buffer, and one of the current multiplexed packets when the multiplexed packets are continuously created. A backward Intra packet offset memory that stores an offset value up to a multiplexed packet that includes image encoded data that has been encoded in the past frame, and one intra-frame encoding in the future from the current multiplexed packet
Forward Intra packet offset memory for storing the offset value up to the multiplexed packet including the encoded image data , the multiplexed packet size calculated by the multiplexed packet size calculation means , and the backward Intra packet A backward Intra packet offset calculating means for calculating a backward Intra packet value by using the contents of the offset memory, and a forward Intra for calculating a forward Intra packet value by using the multiplexed packet size and the contents of the forward Intra packet offset memory. Packet offset calculation means and the above-mentioned forward and backward Intra packet offset calculation
The offset value calculated by the method is included in the multiplexing header.
A video / audio coded data multiplexing device comprising: a means for creating a header . 2. A multiplexed packet reading device for continuously reading Intra packets from the multiplexed data multiplexed by the audio-video coded data multiplexing device according to claim 1, for reading multiplexed packets. Means, a multiplex header analysis means for acquiring the forward and backward Intra packet offsets from the multiplexed header of the read multiplexed packet, and the forward and backward Intra packet offsets, by using the forward and backward Intra packets at the beginning of the read position. A multiplexed data reading apparatus, comprising: a moving reading position moving means.