JPH07321668A - High efficiency data transmission storage device - Google Patents

Abstract

PURPOSE:To send/store data efficiently by eliminating and decreasing stuffing bits inserted in coded data such as a video image and an audio signal. CONSTITUTION:A video coder 1 and an audio coder 2 encode a video image and an audio signal to provide the output of coded data and when the data to be coded run short or are decreased in the quantity, stuffing bits are inserted into coded data and the result is outputted to match the data rate with a prescribed data rate. A user data coder 3 codes user data generated in a burst way and provides an output. Video and audio data stuffing bit detectors 4, 5 detect the inserting state of stuffing bits in the coded data. When a data multiplexer 7 multiplexes the coded data of video and audio signal, the multiplexer 7 replaces the stuffing bits with user data based on the information from the detectors 4, 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for efficiently transmitting or storing data such as video and audio.

[0002]

2. Description of the Related Art Conventionally, when data such as video and audio is coded and transmitted or stored at a constant rate, when the data to be transmitted or stored is exhausted or reduced, the coder has a stuffing bit (for example, zero bit). ), The decoder removes the stuffing bit on the side that receives or reads data by adjusting the rate to a constant rate.

[0003]

In the above prior art, meaningless stuffing bits are inserted in the significant data to be transmitted or stored, and the transmission line or the storage medium is efficiently used. There was a problem in terms.
In particular, when there is no data to be transmitted or stored, or when the amount of data to be stored becomes extremely small, most of the transmitted or stored data is occupied by stuffing bits.

It is an object of the present invention to adjust the data such as video and audio at a constant rate when the data to be transmitted or stored becomes less or less, or to match the constant rate. An object of the present invention is to provide an efficient data transmission / storage device by eliminating or reducing the stuffing bit to be inserted.

[0005]

SUMMARY OF THE INVENTION According to the present invention, when transmitting and accumulating data such as video and audio at a constant rate, the transmission rate is kept constant when there is no or little data to be transmitted or accumulated. To detect the stuffing bit detector, which detects the stuffing state such as the position and length of the stuffing bit inserted in the encoded data, and the detected stuffing state when multiplexing data such as video and audio. Based on the above, by providing a data multiplexer that replaces the stuffing bit inserted in the encoded data such as video and audio with the user data etc., the stuffing bit is not transmitted, stored or reduced. Is the most important feature.

[0006]

In high-efficiency coded video / audio data, etc., the nature of the information source fluctuates with time, so when performing coding control to obtain a constant coding rate, these coded data The rate is not always constant but fluctuates. Therefore, generally, the upper limit value of the rate is set and the data rate is controlled so as not to exceed it. Since it is usually encoded at a predetermined data rate or less,
Stuffing bits (eg, zero bits) are inserted at the data encoder to match a constant data rate.

In the present invention, there is provided a data multiplexer for multiplexing a plurality of data strings (of course, one data string may be inserted) in which the stuffing bits are inserted into one.
When a data string with stuffing bits inserted is received, the stuffing bits need not be always transmitted or stored in burst users, based on the information from the stuffing detector that detects the stuffing bit insertion state. Replace with data and send. on the other hand,
The side receiving the data string in which the stuffing bit is replaced with valid data extracts the user data and processes it as if the stuffing bit was not inserted from the beginning.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is a video encoder for highly efficient coding of video signals, and 2 is a video encoder.
Is a voice encoder for highly efficient encoding of a voice signal, 3 is a user data encoder for encoding user data such as fax and telop, and 4 is a stuffing bit inserted in encoded video data. Video data stuffing bit detector for detecting whether or not there is an audio data stuffing bit detector for detecting whether or not a stuffing bit is inserted in encoded audio data, and 6 for video data, audio Data and
A data multiplexer 7 which replaces the user data and multiplexes it when there is a stuffing bit among them, and 7 is a transmission line or a storage medium for transmitting or storing the multiplexed bit stream.

The video encoder 1 encodes a video signal with high efficiency, adds a video head and sequentially outputs the data, and in order to match the data bit stream to a constant rate, the video data is encoded in the encoded video data. , Insert stuffing bits as needed and output. Similarly, the audio encoder 2 also performs high-performance encoding of an audio signal, adds an audio header, and sequentially outputs it, but it is necessary in the encoded audio data in order to adjust the output bit stream to a constant rate. Stuffing bits are inserted according to the required amount and output. The user data encoder 3 encodes user data such as fax and telop that occur in bursts, adds a user data header, and outputs the header.

Video data stuffing bit detector 4
Then, the video data bit stream output from the video encoder 1 is input to detect whether or not the stuffing bit is inserted. When the insertion of the stuffing bit is detected, the position and length of the stuffing bit are detected. Notify the data multiplexer 6 (may be the amount).
At the same time, the video data stuffing bit detector 4
Sends the video data bit stream from the video encoder 1 to the data multiplexer 6 as it is. When the voice data stuffing bit detector 5 also inputs the voice data bit stream output from the voice encoder 2 and detects that the stuffing bit is inserted,
The stuffed position and length are notified to the data multiplexer 6, and at the same time, the audio data bit stream is sent to the data multiplexer 6.

The data multiplexer 6 multiplexes the video data bit stream from the video encoder 1 and the audio data bit stream from the audio encoder 2, and further, if necessary, from the user data encoder 3. User data is also multiplexed and sent to the transmission path or the storage medium 7. At this time, the data multiplexer 6 determines whether the video and / or audio data bit stream is based on the stuffing position and length (stuffing state) from the video and / or audio data stuffing bit detectors 4, 5. The user data from the user data encoder 3 is inserted into the stuffing bit position, and a code indicating the user data is added to the user data. If the number of stuffing bits in the video and / or audio data bit stream is smaller than that of the user data, the user data is inserted in multiple times.

Next, the operations of the video data stuffing bit detector 4, the audio data stuffing bit detector 5, and the data multiplexer 6 will be specifically described.

The output data bit streams of the video encoder 1 and the audio encoder 2 are shown in FIGS. 2 and 3, respectively.
Further, the output user data stream of the user data encoder 3 is shown in FIG. The audio and video data bit stream is composed of a header, data, and stuffing bits. The bit stream of user data is composed of a header and data. The required amount of stuffing bits is inserted as needed. The stuffing bit has a value of 0
Is a bit string of. Here, the lengths of the header, data, and stuffing bit are all 8 bits. A specific code indicating the type of data is inserted at the beginning of the header of video, audio, and user data. For example, the voice is “0000 0000 0000 0000 0000.
0001 ", video is" 0000 0000 0000 0 "
000 0000 0010 ”, user data is“ 000
0 0000 0000 0000 0000 0100 "
Is a code unique to the bitstream (hereinafter referred to as sync byte). The stuffing bit is inserted after the audio or video data and before the next header. Therefore, the stuffing bit detectors 4 and 5
Can detect the position and length (quantity) of the stuffing bit by detecting the boundary between audio or video data and the stuffing bit and the unique code of the header. Since all data is in units of 8 bits, as shown in FIG. 5, a boundary between video data and 0 bytes (data in which eight 0s are continuous) can be detected. If the first detected 0 byte is the first byte of the sync byte, it is determined that there was no stuffing bit in the meantime. If the detected 0 byte is not the first byte of the sync byte, the data from the first detected 0 byte to the sync byte is all stuffing bits. The stuffing bit detectors 4 and 5 output a pulse signal, which is 0 during the stuffing bit period and 1 during the other period, to the data multiplexer 6 together with the input bit stream as stuffing state information.

The data multiplexer 6 multiplexes a plurality of bit streams into one bit stream. FIG. 6 shows a multiplexed stream (conventional example) when the stuffing bits are not replaced. FIG. 7 shows a multiplexed bit stream when the stuffing bits are replaced with user data. The data multiplexer 6 multiplexes the user data together with the user data header to the corresponding position during the period in which the pulse indicating the stuffing bit period is 0.
This is indicated by the periods A and 3 in FIG. Note that FIG.
Is an example in which the stuffing bit in the audio data is replaced with the user data, but the stuffing bit in the video data may be targeted, or both the audio data may be targeted by the projection color.

As described above, in the embodiment shown in FIG. 1, when stuffing bits are output from the video encoder 1 and the audio encoder 2, user data is inserted instead of transmitting and accumulating these stuffing bits. can do. On the side that receives the data bitstream in which the stuffing bits are replaced with the user data (for example, FIG. 7), the data bitstream is separated according to the header type, and the data bitstream is separated into the video decoder, audio decoder, and data decoder, respectively. Since it is output, the conventional video, audio, and data decoder can be used without any change.

In the embodiment of FIG. 1, the video encoder 1 and the audio encoder 2 send the video and audio data bit streams to the video stuffing bit detector 4 and the audio stuffing bit detector 5, respectively. At the same time, the data may be sent to the data multiplexer 6. In this case, the stuffing bit detectors 5 and 6 need only notify the data multiplexer 6 of the stuffing detection result.

In the embodiment of FIG. 1, the target coded data for replacing the stuffing bit with the user data is two kinds of video and audio data. However, the target coded data is not limited to this, and generally one or more kinds may be used. .

[0019]

As described above, according to the present invention, the meaningless stuffing bit inserted in the coded data is replaced with other valid data such as user data, so that it is efficient. Various data transmission and storage can be performed. Also, by adding a code for identifying the valid data to the replaced valid data, the valid data can be separated / extracted based on the code on the side receiving the data string. It can be used without any changes to the container.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing output data of a video encoder.

FIG. 3 is a diagram showing output data of a speech encoder.

FIG. 4 is a diagram showing output data of a user data encoder.

FIG. 5 is a diagram showing boundaries between significant data and stuffing bits.

FIG. 6 is a diagram showing an output example of a conventional data multiplexer.

FIG. 7 is a diagram showing an output example of a data multiplexer according to the present invention.

[Explanation of symbols]

 1 Video Encoder 2 Audio Encoder 3 User Data Encoder 4 Video Data Stuffing Bit Detector 5 Audio Data Stuffing Bit Detector 6 Data Multiplexer 7 Transmission Line or Storage Medium

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Claims (2)

[Claims] 1. Means for inserting stuffing bits into encoded data to encode the data and to match a constant data rate; and inserting stuffing bits into the encoded data. A means for detecting the state in which the stuffing bit is inserted, based on the detection result of the state in which the stuffing bit is inserted, a means for replacing the stuffing bit in the encoded data with another valid data and outputting the data. A high-efficiency data transmission / accumulation device having: 2. The high-efficiency data transmission / accumulation device according to claim 1, wherein the means for replacing the stuffing bit in the encoded data with another valid data and outputting the stuffing bit is the valid data. A high-efficiency data transmission / accumulation device characterized in that a code for identifying data is added and output.