JP2007027812A - Video stream processing apparatus, integrated circuit device, and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video stream processing apparatus capable of combining transmitted TS packets in a segmented state without the need for using uniquely attached information. <P>SOLUTION: A communication processing section 32 receives an IP packet storing transmitted IS packets in a segmented state and a control section 43 of a stream processing section 41 buffers the segmented TS packets being a payload of the IP packet to a buffer memory every time acquiring the IP packet, extracts buffered data by each size of the TS packets and outputs the data to a decoder 33. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a video stream processing apparatus and the like, and more particularly, to a technique for processing a video stream that is composed of a sequence of fixed-length packets and that is transmitted after being divided into transmission units different from the packets.

  In recent years, digital broadcasting is rapidly spreading. In digital broadcasting, broadcast data including video and audio is transmitted using a stream. For example, in digital broadcasting performed through terrestrial and satellite waves, so-called radio broadcasting, broadcast data is transmitted using MPEG (Moving Picture Expert Group) -2 TS (Transport Stream) composed of a sequence of 188-byte fixed-length packets. Is done. In addition to such radio wave broadcasting, digital broadcasting is also performed as so-called Internet broadcasting through a network.

  FIG. 1 is a functional block diagram schematically showing a configuration example of a transmission system that performs radio wave broadcasting and network broadcasting. In radio broadcasting, the broadcasting station 10 sends out 188-byte fixed-length packet sequences TS1, TS2, and TS3 representing broadcast data, the tuner unit 31 in the receiving device 30 receives the packet sequence, and the decoder 33 receives it. Play video and audio from packet sequence.

  On the other hand, in network broadcasting, the video distribution server 20 stores and sends out 188-byte fixed-length packet sequences TS1, TS2, and TS3 representing video and audio in a transmission unit suitable for the external network 25. One typical example of the external network 25 is the Internet. In this case, the transmission unit is an IP (Internet Protocol) packet. When some TS packets are stored in an IP packet, they are divided, for example, TS2 shown in the lower part of FIG.

  In the receiving device 30, the communication processing unit 32 receives an IP packet having a TS packet as a payload, extracts the TS packet from the received IP packet, and outputs the TS packet to the decoder 33. This TS packet is generally divided.

  However, there are decoders that cannot normally decode when a TS packet is divided and given, such as a decoder that presupposes radio broadcast in which an undivided TS packet is acquired. An apparatus for supplying an unbroken TS packet to such a decoder is known (see, for example, Patent Document 1).

  FIG. 2 is a functional block diagram showing a configuration example of a transmission system obtained by adding the packet stream dividing device 21 and the packet stream combining device 26 disclosed in Patent Document 1 to the configuration related to the network broadcasting shown in FIG. is there.

The serial number assigning means 22 in the packet stream dividing device 21 allocates serial numbers to the TS packets, stores the TS packets in transmission units, and transmits them to the external network 25. The serial number extraction means 27 in the packet stream combiner 26 extracts the serial number from the data received from the external network 25, and the buffer means 28 combines the TS packet fragments whose extracted serial numbers match to combine the original complete TS packet. Get.
JP 2000-299702 A

  However, according to the above-described conventional technique, it is necessary to deal with a unique method that does not exist in standard standards such as MPEG, in which serial numbers are handled on both the transmission side and the reception side. Another problem is that traffic increases because serial numbers are transmitted.

  The present invention has been made in view of the above problems, and can divide and transmit TS packets that are divided and transmitted without using additional information unique to the prior art. An object is to provide a video stream processing apparatus.

  In order to solve the above problems, a video stream processing apparatus according to the present invention is a video stream processing apparatus that processes a video stream that is composed of a fixed-length packet sequence and is transmitted in a transmission unit different from the packet. A buffer memory and control means for acquiring the video stream and buffering it in the buffer memory, and outputting the buffered video stream to the outside for each fixed length.

  According to this configuration, the buffered data is buffered once, and then the buffered data is taken out for each fixed length that is the original length of the packet, so that the fragmentation can be performed without using any additional information unique to the packet. Can be combined to obtain the original individual packets.

  Further, it is defined that the video stream includes a delimiter having a predetermined value for each of the fixed lengths, and the control unit includes the delimiter in a predetermined part of the video stream recently acquired. A synchronization detection unit that determines whether or not each fixed length is included may include canceling at least one of the buffering and the output when a negative determination is made by the synchronization detection unit.

  The synchronization detection unit acquires the video stream and makes the determination, and outputs the acquired video stream when an affirmative determination is made, and outputs the acquired video stream when a negative determination is made. The control means further includes: an input control unit that buffers the video stream output from the synchronization detection unit in the buffer memory; and the buffered video stream to the outside for each fixed length. You may have an output control part to output.

  In addition, the control means further acquires the video stream, buffers the acquired video stream in the buffer memory, and outputs the buffered video stream to the synchronization detection unit. An output control unit, and the synchronization detection unit performs the determination based on the video stream supplied from the output control unit, and when an affirmative determination is made, the synchronization detection unit externally outputs the supplied video stream for each fixed length. When a negative determination is made, the given video stream may be discarded without being output to the outside.

  According to this configuration, it is possible to stop the output of the buffered data by knowing that the transmission unit has been lost because the delimiter cannot be obtained for each fixed length. Can avoid the inconvenience that data including a plurality of packet fragments is output to the outside.

  Further, the video stream processing device includes a communication processing unit that receives the video stream from an external network for each transmission unit, and outputs the received video stream to the control unit. A video stream may be acquired from the communication processing means.

  According to this configuration, it is possible to obtain a highly convenient video stream processing apparatus that has both a reception function of a transmission unit and a function of combining divided packets to obtain original individual packets.

  Further, the present invention can be realized not only as such a video stream processing apparatus, but also as a video stream processing method including steps executed by characteristic means included in such a video stream processing apparatus. It can also be realized as an integrated circuit device for video stream processing.

  According to the video stream processing apparatus of the present invention, the buffered data is once buffered and then the buffered data is taken out for each original length of the packet, so that the original additional information is not used at all. Therefore, the original packets can be obtained by combining the divided packets more simply than in the past.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 3 is a functional block diagram showing a configuration example of the receiving apparatus according to the first embodiment of the present invention. The receiving device 40 is a device that receives a video stream distributed by Internet broadcasting and decodes it into video and audio, and includes a communication processing unit 32, a stream processing unit 41, and a decoder 33. Here, the stream processing unit 41 corresponds to the video stream processing apparatus in the first embodiment.

  In this net broadcasting, broadcast data including video and audio is represented in the MPEG-2 TS described in the section of the prior art, and is distributed from a video distribution server (not shown) to the receiving device 40 via the external network 25. And The external network 25 is the Internet as an example, and TS packets are stored and transmitted in IP packets serving as transmission units. As described in the problem section, the TS packet can be divided during the storage.

  The communication processing unit 32 is a conventional network adapter, and takes out a TS packet that is a payload every time an IP packet is acquired from the external network 25, that is, for each transmission unit, and outputs the TS packet to the stream processing unit 41. Some TS packets are output to the stream processing unit 41 in a divided state like TS2 shown in this example.

  Under the control of the control unit 43, the stream processing unit 41 sequentially buffers the TS packets provided from the communication processing unit 32 in the buffer memory 42, and converts the buffered data into TS packets every 188 bytes as a decoder 33. Output to. The control unit 43 does not output data when the amount of buffered data is less than 188 bytes.

  The stream processing unit 41 can be realized as, for example, a semiconductor integrated circuit device. In this case, the control unit 43 and the buffer memory 42 correspond to circuit blocks that perform the respective functions.

  The decoder 33 decodes the TS packet given from the stream processing unit 41 into video and audio.

  FIG. 4A is a diagram illustrating an example of the operation of the stream processing unit 41. TS packets that arrive after being stored in IP packets are buffered in the buffer memory 42 in the order of arrival, and the buffered data is transferred to the decoder 33 for each TS packet length.

  In this way, even when the TS packet is divided and arrives, the stream processing unit 41 correctly combines the TS packets and delivers them to the decoder 33. Moreover, since this process does not require any additional information of its own, if the transmission side simply stores the TS packet in the IP packet and sends it out, the TS packet that was divided at the time of storage is very simple at the reception side. And it becomes possible to couple | bond correctly.

<Problems caused by packet loss>
So far, according to the video stream processing apparatus according to the first embodiment, it has been described that the divided TS packets can be combined extremely simply and accurately. However, when an IP packet is lost, the following problem occurs.

  FIG. 4B is a diagram showing another example of the operation of the stream processing unit 41, and shows an example in which one IP packet is lost in, for example, an external network. In this case, data having the same size as that of a TS packet including a plurality of TS packet fragments is transferred to the decoder 33 instead of individual TS packets that are correctly combined.

  The following describes a video stream processing apparatus that can cope with this problem.

<Second Embodiment>
FIG. 5 is a functional block diagram showing a configuration example of the stream processing unit 41a according to the second embodiment of the present invention. The stream processing unit 41a is a processing unit in which a function of detecting a loss of an IP packet and stopping data buffering is added to the above-described stream processing unit 41, and includes a synchronization detection unit 44, an input control unit 45, a buffer memory 42 and an output control unit 46. Here, the synchronization detection unit 44, the input control unit 45, and the output control unit 46 are the details of the control unit 43 shown in FIG.

  The second embodiment uses the fact that the first byte of the MPEG-2 TS packet is defined as 0x47. This 0x47 data is an example of a delimiter included in a video stream composed of a fixed-length packet sequence for each packet length.

  The stream processing unit 41a operates in one of the detection state, which is the initial state, and the transfer state. The operation state is managed by the synchronization detection unit 44.

  In the detection state, the synchronization detection unit 44 analyzes the data provided from the communication processing unit 32, and the data provided until the 0x47 data is detected continuously for the number of times indicated in the detection reference number register 43a every 188 bytes. Is discarded without being output to the input control unit 45. And if a detection is made, it will transfer to a transfer state. In the detection reference number register 43a, when the stream processing unit 41a starts operation, for example, a CPU (Central Processing Unit) (not shown) sets a detection reference number (for example, three times). To do.

  In the transfer state, the synchronization detection unit 44 analyzes the data provided from the communication processing unit 32 and outputs it to the input control unit 45. When the detection is lost, that is, 0x47 data is not detected even once every 188 bytes. If it is detected, the input controller 45 is notified of the detection failure and shifts to the detection state.

  The input control unit 45 sequentially buffers the data provided from the synchronization detection unit 44 in the buffer memory 42. When a notification of detection failure is received from the synchronization detection unit 44, the last buffered data for 188 bytes or all buffered data is deleted.

  The output control unit 46 outputs the data buffered in the buffer memory 42 in units of 188 bytes. If the buffered data amount is less than 188 bytes, no data is output.

  FIG. 6 is a flowchart showing the operation of the stream processing unit 41a, and shows an example in which a value indicating 3 is set in the detection reference number register 43a.

  The stream processing unit 41a repeatedly executes steps S02 to S07 until an instruction to terminate the process is given from the outside such as a CPU (S01).

  The synchronization detection unit 44 operates as a detection state until it detects 0x47 data three times every 188 bytes in the data given from the communication processing unit 32, and continues to discard the given data (S02 to S03). . In this state, new data is not buffered, and as a result, no data is output from the output control unit 46 to the decoder 33.

  When the synchronization detection unit 44 detects 0x47 data three times continuously for every 188 bytes in the given data, the synchronization detection unit 44 shifts to a transfer state and transfers the data from the communication processing unit 32 via the input control unit 45 to the buffer memory 42. Starts buffering (S04). While 0x47 data continues to be detected every 188 bytes, it operates as a transfer state (S05), and the output control unit 46 outputs the buffered data to the decoder 33 every 188 bytes (S06).

  When the detection is lost, the synchronization detection unit 44 notifies the input control unit 45 of the detection failure and shifts to a detection state (S07). The input control unit 45 receives a notification of detection failure and erases part or all of the buffered data.

  As described above, the stream processing unit 41a detects packet loss due to the fact that 0x47 data is not obtained every 188 bytes, stops buffering new data, and erases buffered data. Therefore, a situation in which data having the same size as a TS packet including a plurality of TS packet fragments is transferred to the decoder 33 is avoided.

  Here, the number of times of continuous detection of 0x47 data is determined in order to reduce the possibility of misidentifying 0x47 data included in main broadcast data as a delimiter. The number of times is not limited to three, and a preferable number according to the design may be appropriately set in the detection reference number register 43a.

<Third Embodiment>
FIG. 7 is a functional block diagram showing a configuration example of the stream processing unit 41b according to the third embodiment of the present invention. The stream processing unit 41b is a processing unit to which the function of detecting the loss of an IP packet and stopping the output of data is added to the above-described stream processing unit 41, and includes an input control unit 47, a buffer memory 42, and an output control unit 48. , And a synchronization detector 49. Here, the input control unit 47, the output control unit 48, and the synchronization detection unit 49 are the details of the control unit 43 shown in FIG.

  In the third embodiment, as in the second embodiment, the fact that the first byte of the MPEG-2 TS packet is defined as 0x47 is used.

  The stream processing unit 41b operates in one of the detection state and the transfer state, which is an initial state. The operation state is managed by the synchronization detection unit 49.

  The input control unit 47 sequentially buffers the data provided from the communication processing unit 32 in the buffer memory 42.

  The output control unit 48 shifts to a detection state when a detection error is input from the synchronization detection unit 49, and shifts to a transfer state when a detection start is input. The output control unit 48 outputs the data buffered in the buffer memory 42 to the synchronization detection unit 49 sequentially in the detection state and in units of 188 bytes in the transfer state. If the buffered data amount is less than 188 bytes, no data is output.

  In the detection state, the synchronization detection unit 49 analyzes the data supplied from the output control unit 48, and until the 0x47 data is detected continuously for the number of times indicated in the detection reference number register 43a every 188 bytes, the supplied data Are discarded without being output to the decoder 33. When the detection is made, the output control unit 48 is notified of the start of detection, and shifts to the transfer state. In the detection reference number register 43a, when the stream processing unit 41a starts operation, for example, a CPU (Central Processing Unit) (not shown) sets a detection reference number (for example, three times). To do.

  In the transfer state, the synchronization detection unit 49 analyzes the data supplied from the output control unit 48 and outputs it to the decoder 33. When the detection is lost, that is, 0x47 data is not detected even once every 188 bytes, for example. In such a case, the output control unit 48 is notified of the detection failure and shifts to the detection state.

  FIG. 8 is a flowchart showing the operation of the stream processing unit 41b, and shows an example in which a value indicating 3 is set in the detection reference number register 43a.

  The stream processing unit 41b repeats steps S12 to S18 until it is instructed from the outside to end the processing (S11).

  In the detection state, the output control unit 48 sequentially outputs the data in the buffer memory to the synchronization detection unit 49 (S12). The synchronization detecting unit 49 operates as a detection state until it continuously detects 0x47 data every 188 bytes in the data given from the output control unit 48, and continues to discard the given data (S13 to S14). .

  When the synchronization detection unit 49 detects 0x47 data three times continuously for every 188 bytes in the given data, the synchronization detection unit 49 notifies the output control unit 48 of the start of detection, shifts to the transfer state, and the output control unit 48 In response to the detection start input, the state shifts to the transfer state, and the data in the buffer memory is output to the synchronization detection unit 49 in units of 188 bytes (S15). Then, while 0x47 data is continuously detected every 188 bytes, it operates as a transfer state (S16), and the synchronization detector 49 outputs the data given every 188 bytes from the output controller 48 to the decoder 33 (S17). .

  When the detection is lost, the synchronization detection unit 49 notifies the output control unit 48 of the detection failure and shifts to a detection state (S18).

  As described above, the stream processing unit 41b detects a packet loss because 0x47 data is not obtained every 188 bytes, and stops outputting buffered data to the decoder. A situation in which data having the same size as a TS packet including packet fragments is transferred to the decoder 33 is avoided.

<Modification>
In the second and third embodiments, the continuous detection number of the delimiter can be set to be changeable in the detection reference number register 43a. However, the value of the delimiter (0x47 in the example of the embodiment) or It is also conceivable to provide a register that can change the packet length (188 bytes in the embodiment).

  In the second and third embodiments, the packet length is set by the CPU. However, the present invention is not limited to this. For example, the data provided from the communication processing unit 32 is analyzed and the delimiter set by the CPU is analyzed. The data length from when a value is detected until it is next detected may be measured, and the data length may be set as the packet length when detected for the same data length continuously for the detection reference number.

  Further, in the second and third embodiments, the condition until the process is terminated is described as a condition for shifting to the process termination. However, the present invention is not limited to this. For example, data is transmitted from the communication processing unit 32 for a predetermined time. May be shifted to the end state, and it is conceivable to provide a register whose setting can be changed from the outside such as a CPU for the predetermined time.

  In the embodiment, it has been described that the stream processing unit 41 can be realized as a semiconductor integrated circuit. However, the communication processing unit 32 and the stream processing unit 41 may be realized in one semiconductor integrated circuit. Since such a semiconductor integrated circuit has both the conventional network adapter function and the TS packet combining function of the present invention, it is a highly convenient semiconductor that performs from IP packet communication processing to TS packet combining on a single chip. Integrated circuit.

  It is also conceivable to create a circuit block according to the video stream processing apparatus of the present invention in a semiconductor integrated circuit for a decoder. In that case, a decoder that can correctly decode even if the divided TS packet is supplied is realized.

<Summary>
As described above, according to the video stream processing apparatus of the present invention, a fragmented TS packet stored and transmitted in an IP packet is combined extremely simply and accurately without using any additional information of its own. Thus, it is possible to obtain original individual TS packets.

  Furthermore, by detecting the packet loss using the delimiter included in each TS packet, even if there is a bucket loss, data of the same size as the TS packet containing multiple TS packet fragments is output to the outside The situation where it is done can be avoided.

  The present invention can be applied to a video stream processing device, a network adapter, a decoder and the like used in a digital broadcast receiving device.

It is a functional block diagram which shows the structural example of the transmission system which performs the conventional radio wave broadcasting and network broadcasting. It is a functional block diagram which shows the structural example of the internet broadcasting system corresponding to the conventional packet parting. It is a block diagram which shows an example of a functional structure of the receiver which concerns on 1st Embodiment. (A) It is a figure which shows an example of operation | movement of a stream process part. (B) It is a figure which shows another example of operation | movement of a stream process part. It is a functional block diagram which shows the structural example of the stream process part which concerns on 2nd Embodiment. It is a flowchart showing operation | movement of the stream process part which concerns on 2nd Embodiment. It is a functional block diagram which shows the structural example of the stream process part which concerns on 3rd Embodiment. It is a flowchart showing operation | movement of the stream process part which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Broadcasting station 20 Video distribution server 21 Packet stream dividing device 22 Number assigning means 25 External network 26 Packet stream combining device 27 Number extracting means 28 Buffer means 30 Receiving device 31 Tuner unit 32 Communication processing unit 33 Decoder 40 Receiving device 41, 41a, 41b Stream processing unit 42 Buffer memory 43 Control unit 43a Detection reference number register 44 Synchronization detection unit 45 Input control unit 46 Output control unit 47 Input control unit 48 Output control unit 49 Synchronization detection unit

Claims (7)

A video stream processing apparatus configured to process a video stream that is composed of a fixed-length packet sequence and is transmitted by being divided into transmission units different from the packet,
Buffer memory,
A video stream processing apparatus comprising: control means for acquiring the video stream and buffering it in the buffer memory, and outputting the buffered video stream to the outside for each fixed length. The video stream is defined to include a delimiter of a predetermined value for each fixed length,
The control means includes
A synchronization detection unit for determining whether or not the delimiter is included for each fixed length in a predetermined part of the video stream recently acquired;
The video stream processing apparatus according to claim 1, wherein when a negative determination is made by the synchronization detection unit, at least one of the buffering and the output is canceled. The synchronization detection unit obtains the video stream and performs the determination, and outputs the acquired video stream when an affirmative determination is made, and outputs the acquired video stream when a negative determination is made. Destroy,
The control means further includes
An input control unit for buffering the video stream output from the synchronization detection unit in the buffer memory;
The video stream processing apparatus according to claim 2, further comprising: an output control unit that outputs the buffered video stream to the outside for each fixed length. The control means further includes
An input control unit for acquiring the video stream and buffering the acquired video stream in the buffer memory;
An output controller that outputs the buffered video stream to the synchronization detector;
The synchronization detection unit makes the determination based on the video stream supplied from the output control unit, and outputs a given video stream to the outside for each fixed length when an affirmative determination is made. The video stream processing apparatus according to claim 2, wherein the given video stream is discarded without being output to the outside. Furthermore, it comprises a communication processing means for receiving the video stream from the external network for each transmission unit, and outputting the received video stream to the control means,
The video stream processing apparatus according to claim 1, wherein the control unit acquires the video stream from the communication processing unit. An integrated circuit device for video stream processing configured to process a video stream composed of a fixed-length packet sequence and transmitted by being divided into transmission units different from the packet,
Buffer memory,
An integrated circuit device, comprising: a control circuit that acquires the video stream and buffers the video stream in the buffer memory, and outputs the buffered video stream to the outside for each fixed length. A video stream processing method that processes a video stream that is composed of a sequence of fixed-length packets and is transmitted by being divided into transmission units different from the packets,
A buffer step for sequentially buffering a given video stream;
An output step of outputting a buffered video stream for each packet length.

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