JPH10224404A - Device and method for signal transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve resistance to the transmission line errors even against a transmission line of large length or the coexistence of different transmission lines by adding a means which generates a packet from the program stream signals to a program stream signal transmitting device and transmitting the program stream signals as a packet. SOLUTION: In this signal transmission method, a pseudo transport stream (TS) packet is generated from program stream (PS) signals and transmitted. A pseudo TS packet generation circuit 10 is added to a PS signal transmitting device. A PS header detection part 11 of the circuit 10 detects a PS header out of the PS data, and a buffer memory part 12 stores the PS data and reads them out in response to a read clock CLK. A 188-byte frame generation part 13 generates the read clock CLK.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a signal transmission device and a signal transmission method in an MPEG system, and more particularly, to a PS signal transmission device and a signal transmission method for transmitting a PS (Program Stream) signal in an MPEG2 system.

[0002]

2. Description of the Related Art MPEG (Moving Picture) is an international standard for coding moving pictures, especially moving pictures for storage media.
Expert Group).

[0003] MPEG is MPEG1, MPEG2, M
Draft standards for PEG4 at three levels are under study. MPE
G1 aims at compressing a moving image that can be transmitted through a 1.5 Mbps communication line, and is considered to be mainly used for videophones, videoconferencing, and the like. In MPEG1, the current NTSC video image is 320 × 240.
Treat as pixel resolution and make up one frame 2
Data of only one of the fields is used.
MPEG2 aims at compression that can be transmitted over a communication line exceeding 10 Mbps, and targets moving picture transmission and digital video by ISDN or the like. MPEG4 is intended for low bit rates.

When the present invention is applied to an actual application including an encoded stream (bit string) of MPEG video or MPEG audio and other encoded streams, the encoded streams including synchronization are multiplexed and integrated. In addition to the unification, it is necessary to convert the stream into a data format suitable for a unique physical format or protocol of a storage medium or a network.

[0005] In the MPEG2 system, a program stream (MPEG2-PS, PS: Program Stream) constituting one program and a transport stream (MPEG2-TS, TS: TS: Transport Stream).

[0006] The MPEG stream is a byte stream in which many 1-bit flags are arranged, but byte-aligned for each unit such as a header. As a structure common to the entire MPEG system, information indicating the length is placed before the data portion that is not fixed length, and when unnecessary, the portion is skipped, and the head of the next data group is checked and reliable. It has a data structure that enables highly-separable separation processing.

Generally, a program stream (hereinafter, referred to as a program stream)
PS) is transmitted to the other party as it is, and no particular consideration is given to constructing a frame.

[0008]

However, in the conventional MPEG2 system, when the transmission path is long-distance or when several kinds of transmission paths (for example, terrestrial line, satellite line) are mixed, In addition, there is a problem that the influence of a transmission path error caused by noise or the like is large, and there is a high possibility that PS data cannot be transmitted correctly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a signal transmission apparatus and a signal transmission method capable of improving the tolerance against transmission path errors even when the transmission paths are long distances or mixed transmission paths. .

[0010]

A signal transmission apparatus according to the present invention is a signal transmission apparatus for transmitting a PS (Program Stream) signal, comprising packet generation means for generating a packet from a PS signal, and converting the PS signal into a packet. It is characterized by transmission.

[0011] The packet generation means frames the PS signal into a predetermined byte length, and generates a pseudo TS (Transport St.).
ream) It may generate a packet.

[0012] The packet may have a pseudo-TS packet configuration of 188 bytes including a 1-byte TS header and 187 bytes of PS data, and the PS signal may be a MPEG (Moving Picture Expert Group) 2 coding scheme. May be used.

Further, the signal transmission apparatus may include an error correction processing means for performing error correction processing on the packet.

In the signal transmission method according to the present invention, in the signal transmission method for transmitting a PS signal, first, a pseudo TS (Transport Stream) packet is generated from the PS signal, and the generated pseudo TS packet is transmitted. It is characterized by having done.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A signal transmission device and a signal transmission method according to the present invention can be applied to a PS signal transmission device for transmitting a PS signal in an MPEG2 system.

FIG. 1 is a block diagram showing a configuration of a signal transmission device according to an embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a pseudo TS (Transport Stream) packet generation circuit installed in the PS signal transmission device. The pseudo TS packet generation circuit 10 includes a PS header detection unit 11, a buffer memory unit 12, and 188 bytes. It comprises a frame generator 13, a TS header generator 14, and an OR gate 15.

The PS header detector 11 detects a PS header from PS data.

The buffer memory unit 12 accumulates PS data and reads the data according to the read clock from the 188 byte frame generation unit 13.

The 188-byte frame generation unit 13
It consists of an 188 byte counter and generates a clock CLK for generating a pseudo TS packet.

The TS header generator 14 generates a TS header to be added to the generated pseudo TS packet.

As described above, the pseudo TS packet generation circuit 1
Numeral 0 is a circuit for converting the PS signal into a frame and transmitting the PS signal to the other party as a pseudo TS frame (byte length 188). The PS signal is transmitted by the pseudo TS packet generation circuit 10 as a pseudo TS packet.

Next, the operation of the pseudo TS packet generation circuit 10 configured as described above will be described.

The PS data to be transmitted is input to the PS header detection unit 11 and the buffer memory unit 12, and is temporarily stored in the PS header detection unit 11. PS header detector 11
Then, the PS header is detected from the input PS data,
The detected PS header is sent to the 188-byte frame generator 13 and the TS header generator 14 as a trigger of the 188-byte counter.

The 188-byte frame generation unit 13 counts 188 bytes when a trigger is input, generates a 188-byte packet, and reads 187 bytes of the read clock C of the 188-byte packet.
Generate LK.

The buffer memory section 12 receives the read clock CLK from the 188-byte frame generation section 13 and reads 187-byte PS data from the accumulated PS data from the buffer memory section 12 in accordance with the read clock CLK.

The TS header generator 14 generates a TS header when a trigger is input, and outputs a TS header in the 188-byte packet generated by the 188-byte frame generator 13.
A TS header is assigned to one byte excluding the S data.

1 read from the buffer memory unit 12
The OR data of the 87-byte PS data and the 1-byte TS header generated by the TS header generator 14 are output by the OR gate 15 and output as a pseudo TS packet.

As described above, a packet structure is generated in which one byte of the TS header and 187 bytes of the remaining one of the 188 bytes of the TS packet are separated. This packet configuration is called a pseudo TS packet and is as shown in FIG.

Here, in the buffer memory unit 12, since the speed of the PS data on the storage side is faster than the pseudo TS packet on the reading side, it is necessary to transmit a flag so as not to cause overflow.

As described above, the signal transmission device according to the present embodiment converts PS data into a frame,
Since the pseudo TS packet generation circuit 10 for transmitting to the other side as an S frame (byte length 188) is provided,
Data can be transmitted as pseudo TS packets,
Reed-Solomon error correction code, CRC (cyclic redun
Error correction processing such as dancy check (cyclic redundancy check code), scrambling, and convolutional interleaving can be easily realized. If the pseudo TS packet is transmitted after performing the above-described error correction processing, the transmission is performed when the transmission path is long-distance or when several types of transmission paths (for example, terrestrial line and satellite line) are mixed. It is possible to improve the tolerance against transmission errors at the time. Also, pseudo TS
By using packets, TS multiplexing can be easily realized.

In the above embodiment, the MPEG
Although the present invention is applied to a PS signal transmission apparatus for transmitting a PS signal in two systems, it is needless to say that the present invention is not limited to the MPEG2 system, but can be applied to other signal transmission apparatuses, for example, MPEG1.

Also, in the present embodiment, 18
Although a pseudo TS (Transport Stream) packet having a length of 8 bytes is generated, any packet length and stream format may be used as long as the packet is generated and transmitted from the PS signal.

Further, in the present embodiment, the MPEG system can be executed by, for example, a computer.
The present invention can be applied to all moving picture coding apparatuses based on the MPEG algorithm. For example, as a necessary environment for realizing this method, a dedicated machine in which a PEG decoder or the like is externally attached in addition to a workstation or a personal computer may be used.

Further, it goes without saying that the number and types of circuits and members constituting the pseudo TS packet generation circuit of the signal transmission device are not limited to the above-described embodiment, and may be realized by software.

[0036]

According to the signal transmission device and the signal transmission method of the present invention, the packet transmission means for generating a packet from the PS signal is configured to transmit the PS signal as a packet. Even in the case where the transmission line is mixed, the tolerance to the transmission path error can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a pseudo TS packet generation circuit of a signal transmission device according to an embodiment to which the present invention has been applied.

FIG. 2 is a diagram showing a configuration of PS data and a pseudo TS packet of the signal transmission device.

[Explanation of symbols]

Reference Signs List 10 pseudo TS packet generation circuit, 11 PS header detection unit, 12 buffer memory unit, 13 188 byte frame generation unit, 14 TS header generation unit, 15 OR gate

Claims (6)

[Claims] 1. A signal transmission apparatus for transmitting a PS (Program Stream) signal, comprising: packet generation means for generating a packet from the PS signal, wherein the signal transmission apparatus transmits the PS signal as a packet. 2. The method according to claim 1, wherein the packet generation unit converts the PS signal into a frame having a predetermined byte length,
2. The signal transmission device according to claim 1, wherein the signal transmission device generates a (Transport Stream) packet. 3. The packet according to claim 1, wherein the packet is a pseudo-TS packet of 188 bytes including a 1-byte TS header and 187 bytes of PS data.
Or the signal transmission device according to any one of 2. 4. The PS signal is an MPEG (Moving Pic)
3. The signal transmission device according to claim 1, wherein the signal is a signal conforming to a coding expert group (2) coding scheme. 5. The signal transmission device according to claim 1, further comprising: an error correction processing unit that performs an error correction process on the packet. Signal transmission device. 6. A signal transmission method for transmitting a PS (Program Stream) signal, comprising: first, a pseudo TS (Transport Stream) from a PS signal;
A signal transmission method, comprising: generating a packet; and transmitting the generated pseudo TS packet.