KR20070066833A - Digital broadcasting transmission apparatus and processing method for turbo stream thereof and digital broadcasting system - Google Patents

Abstract

A digital broadcasting transmitting apparatus, a turbo stream processing method of the digital broadcasting transmitting apparatus, and a digital broadcasting system including the transmitting apparatus are provided to respectively compress a normal stream and a turbo stream which constitute a dual TS(Transport Stream) by using different compression methods to improve compression performance and picture quality. A digital broadcasting transmitting apparatus includes a first compression unit(10), a second compression unit(20), a TS constitution unit(100), and a TS processor. The first compression unit compresses predetermined audio and video signals according to a first compression method to form a normal stream. The second compression unit compresses predetermined audio and video signals according to a second compression method to form a turbo stream. The TS constitution unit multiplexes the normal stream and the turbo stream to constitute a dual TS. The TS processor robustly processes the dual TS.

Description

Digital broadcasting transmission apparatus and its turbo stream processing method and a digital broadcasting system comprising the same

1 is a block diagram of a digital broadcast transmission apparatus according to a preferred embodiment of the present invention;

2 is a block diagram of a first and a second compression unit and a TS component;

3A to 3B are diagrams illustrating a packet constituted by the TS component shown in FIG. 2;

4 is a flowchart illustrating a turbo stream processing method of a digital broadcast transmission device according to the present invention.

5 is a block diagram of a digital broadcast receiving apparatus according to a preferred embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: TS configuration section 110: H.264 compression section

120: RS Encoder 130: Place Holder Maker

140: Interleaver 150: TS mux

The present invention relates to a digital broadcast transmission apparatus, a method for processing a turbo stream thereof, and a digital broadcast system including the same. More particularly, the present invention relates to a digital broadcast transmission apparatus for processing a turbo stream and a normal stream compressed by different methods. A stream processing method and a digital broadcasting system including the same.

Digital broadcasting standards include the US ATSC (Advanced Television System Committee) and the European DVB-H (Digital Video Broadcasting-Handheld).

Among these, the US transmission method is based on the NTSC frequency band, and has advantages in terms of ease and economics of transceiver implementation. The US transmission method is a single carrier amplitude modulated residual band (VSB), which can transmit high quality video, audio, and auxiliary data in a single 6 MHz bandwidth.

In the American transmission method, video signals are compressed to Moving Picture Experts Group-2 (MPEG-2), and audio and audio signals are compressed to AC-3 (Digital Audio Compression). Vestigial Side Band technology.

The reason for compressing the video signal to MPEG-2 and for compressing the audio and audio signals to AC-3 is to reduce the bit rate of the video, audio, and digital auxiliary data streams.

MPEG-2, which is used for the compression of video signals in the US-type transmission method, was developed for cases in which channel bandwidth, storage media capacity, etc. are limited and an efficient transmission structure is needed, and is designed to interoperate with ATM transmission structure. That's the way.

Recently, the trend has been changed from the conventional method of using only a normal stream to a method of applying a dual transport stream in which a turbo stream with enhanced coding is added to the normal stream.

In this case, a turbo stream compressed by MPEG-2, which is a conventional compression method, exhibits a phenomenon in which compression performance and image quality are considerably degraded. Accordingly, there is a problem that the burden on the transmission system and the operating cost of the broadcaster increases.

Accordingly, an object of the present invention is to provide a digital broadcast transmission apparatus and a turbo stream processing method thereof capable of improving compression performance and image quality by compressing a normal stream and a turbo stream constituting a dual transport stream by different compression methods, and the same. It is to provide a digital broadcasting system.

According to an aspect of the present invention, there is provided a digital broadcast transmission apparatus comprising: a first compression unit configured to compress a predetermined audio signal and a video signal by a first compression method to form a normal stream, a predetermined audio signal, and A second compression unit that compresses a video signal by a second compression method to form a turbo stream, a TS component that forms a dual transport stream by multiplexing a normal stream and a turbo stream, and a TS And a TS processor for robustly processing the dual transport stream transmitted from the component.

Preferably, the first compression scheme may be Moving Picture Experts Group-2 (MPEG-2), and the second compression scheme may be H.264.

Also preferably, the TS component may include an RS encoder for RS encoding the configured turbo stream, a place holder maker for adding a parity insertion region to the RS encoded turbo stream, an interleaver for interleaving the turbo stream with the parity insertion region, and the interleaved turbo. And a TS mux for multiplexing the stream and the configured normal stream.

On the other hand, the turbo stream processing method of the digital broadcast transmission apparatus according to the preferred embodiment of the present invention comprises the steps of configuring a normal stream by compressing a predetermined audio signal and a video signal by a first compression method, a predetermined audio signal and video signal Compressing by a second compression method to form a turbo stream, multiplexing the normal stream and the turbo stream to configure a dual transport stream and the robust processing of the configured dual transport stream.

Preferably, the first compression scheme may be Moving Picture Experts Group-2 (MPEG-2), and the second compression scheme may be H.264.

Also preferably, configuring the dual transport stream includes: RS encoding the configured turbo stream, adding a parity insertion region to the RS encoded turbo stream, interleaving the turbo stream with the parity insertion region added, and interleaving. Multiplexing the configured turbo stream and the configured normal stream.

In addition, the digital broadcasting system according to the preferred embodiment of the present invention configures a dual transport stream by multiplexing the normal stream compressed by the first compression method and the turbo stream compressed by the second compression method, and the dual transport stream is robust. And a receiving device for receiving and processing the outputted dual output stream, and decoding and restoring the normal stream and the turbo stream, respectively.

Preferably, the first compression scheme may be Moving Picture Experts Group-2 (MPEG-2), and the second compression scheme may be H.264.

Also preferably, the transmission apparatus compresses a predetermined audio signal and a video signal by a first compression method to form a normal stream, compresses the predetermined audio signal and a video signal by a second compression method, and turbos. The second compression unit constituting the stream may include a TS component configured to configure a dual transport stream by multiplexing the normal stream and the turbo stream, and a TS processor configured to robustly process the dual transport stream transmitted from the TS component. .

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a block diagram of a digital broadcast transmission apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 1, the digital broadcast transmission apparatus 1000 according to the preferred embodiment of the present invention includes a TS component 100 and a TS processor 200.

The TS component 100 configures a dual transport stream by multiplexing a turbo stream and a normal stream. The TS component 100 will be described in more detail later with reference to FIG. 2.

The TS processing unit 200 robustly processes the dual transport stream transmitted from the TS configuration unit 100 and transmits it to the receiving device. The TS processing unit 200 includes a randomization unit 201, an RS encoder (Reed-Solomon encoder) 203, a data interleaver 205, a turbo processing unit 207, a trellis encoder 209, a mux (MUX) 211. ), A pilot inserter 213, a modulator 215, and an RF converter 217.

The randomization unit 201 randomizes the dual transport stream. The operation of randomizing the dual transport stream by the randomization unit 201 is to increase the utilization of the allocated channel space.

The RS encoder 203 RS encodes the dual transport stream randomized by the randomization unit 201. The RS encoder 203 may be in the form of a concatenated coder that adds parity to the transport stream to correct errors that may occur due to channel characteristics in the transmission process.

The data interleaver 205 interleaves the RS-encoded dual transport stream by the RS encoder 203. Here, data interleaving refers to changing their position within a frame of data, rather than changing the data.

In this embodiment, the data interleaver 205 is illustrated as being located between the RS encoder 203 and the turbo processing unit 207, but this is not necessarily limited thereto. For example, the data interleaver 205 may be located between the turbo processor 207 and the trellis encoder 209.

The turbo processing unit 207 robustly processes the dual transport stream interleaved by the data interleaver 205. More specifically, the turbo processor 207 separates the dual transmission stream into a normal stream and a turbo stream, passes the normal stream as it is, turbo codes only the turbo stream, and then multiplexes the normal stream and the turbo coded turbo stream. To print.

The trellis encoder 209 trellis encodes the dual transport stream that has been robustly processed by the turbo processor 207. The trellis encoder 209 converts the dual transport stream into a symbol and performs symbol mapping through trellis coding at a predetermined rate.

The mux 211 multiplexes the segment sync signal and the field sync signal to the trellis encoded dual transport stream by the trellis encoder 209.

The pilot inserting unit 213 adds a pilot signal to the transport stream to which the field sync signal and the segment sync signal are added by the mux 211. Here, the pilot signal has a slight DC shift applied to the 8-VSB baseband just before modulation, and a slight residual carrier appears at the zero frequency point of the modulated spectrum, regardless of the transmitted signal. It is a signal that plays a role in synchronizing.

The modulator 215 performs pulse shaping on the transport stream to which the pilot signal is added by the pilot inserter 213, and performs VSB modulation on the intermediate frequency carrier to modulate amplitude.

The RF converter 217 RF-converts and amplifies the VSB modulated transport stream by the modulator 215 and transmits the amplified band through a channel allocated to a predetermined band.

2 is a block diagram of a first and a second compression unit and a TS component.

Referring to FIG. 2, the first compression unit 10 and the second compression unit 20 are configured at the front end of the TS component 100 according to the present invention, and the TS component 100 is an RS encoder 120. , A place holder maker 130, an interleaver 140, and a TS mux 150.

The first compressor 10 compresses a predetermined audio signal and a video signal by a first compression method to form a normal stream, and the normal stream that is compressed by the first compressor 10 is the TS component 100. ) Is entered. Here, the first compression scheme is preferably Moving Picture Experts Group-2 (MPEG-2).

The second compressor 20 compresses a predetermined audio signal and a video signal by a second compression method to form a turbo stream, and the turbo stream compressed by the first compressor 20 is the TS component 100. ) Is entered. Here, the second compression method is preferably H.264.

H.264, also known as Advanced Video Coding, is a standard for the coded representation of visual information, emphasizing efficiency and reliability. In addition, the H.264 method has a compression efficiency of approximately 2 times (about 50%) and MPEG times 1.5 times (about 35%) than the MPEG-2 method. In real-time compression such as broadcasting, the performance difference is somewhat reduced, but shows 30-40% better efficiency compared to MPEG-2.

For example, to implement SD quality, MPEG-2 requires 4Mbps (4 million bits per second) bit rate (digital signal transmission rate), but H.264, half of 2Mbps is sufficient. In addition, to implement HD quality image quality, 9Mbps should be sent by MPEG-2 method, but 5Mbps should be sufficient by H.264 method.

Good compression efficiency means less image quality loss even with higher compression ratios. Increasing the compression rate reduces the capacity, so if the compression performance is good, it is possible to achieve a good resolution even when transmitting a small capacity digital signal.

In addition, being able to implement a good resolution even with a small capacity means that fewer frequencies corresponding to the transmission path are used. In a limited frequency resource, the H.264 scheme may have a small capacity in the same frequency band, thus providing a margin in frequency. Accordingly, more channel services are possible when using the H.264 method.

The RS encoder 120 encodes by adding parity to the turbo stream compressed by the second compression unit 20 in the H.264 manner.

The place holder maker 130 generates an area for inserting the parity to be added by the turbo processing unit 207 of the TS processing unit 200 to the turbo stream to which parity is added by the RS encoder 120. For example, two bytes can be generated by configuring one byte of eight bits, which is a structural unit of a turbo stream, with one byte of four bits.

The interleaver 140 interleaves the turbo stream in which a region for inserting parity is generated. The interleaver 140 may be omitted if necessary and may be replaced with another one. However, when the RS encoder 120 is included in the TS component 100, the interleaver 140 may also be included.

The TS mux 150 multiplexes the normal stream inputted to the TS configuration unit 100 and the turbo stream interleaved by the interleaver 140 to form a dual transport stream, and outputs the configured dual transport stream.

3A to 3B are diagrams illustrating a packet configured in the TS configuration unit shown in FIG.

In general, a packet applied to digital broadcasting is composed of a sync signal of 1 byte, a header of 3 bytes, and a payload of 184 bytes, and the header of the packet includes a packet identifier (PID). Include. Here, the normal stream and the turbo stream are classified according to the type of data included in the payload portion.

FIG. 3A illustrates an example of a turbo stream input to the TS component 100, and includes turbo data in a payload part and is compressed in an H.264 manner by the second compression unit 20. The turbo stream is processed by the RS encoder 120, the place holder maker 130, and the interleaver 140 in the TS component 100 and then input to the TS mux 150.

3B illustrates an example of a normal stream input to the TS component 100. The payload portion includes normal data, but includes an adaptation field into which turbo data is inserted in consideration of combining with the turbo stream. Adaptation field). The adaptation field includes two bytes of AF header and N bytes of null data space.

The turbo stream shown in (a) of FIG. 3A and the normal stream shown in (b) of FIG. 3A are multiplexed in the TS mux 150, and are composed of dual transport streams as shown in (c) of FIG. 3A. .

3B shows another combination of a turbo stream and a normal stream, in which one entire packet includes turbo data or normal data, and in the TS mux 140, the turbo stream and the normal stream are in a ratio of 1: 3. To place. Here, although the turbo stream and the normal stream are arranged at a ratio of 1: 3, this is not necessarily limited thereto.

The dual transport streams shown in FIGS. 3A and 3B are similar to the dual transport streams compressed by the conventional MPEG-2 method, but the turbo streams are compressed by the H.264 method, thereby providing superior efficiency compared to the normal stream. Indicates.

4 is a flowchart illustrating a turbo stream processing method of a digital broadcast transmission device according to the present invention.

Here, a turbo stream processing method of a digital broadcast transmitting apparatus according to the present invention will be described with reference to FIGS. 1 to 4.

The first compression unit 10 compresses the audio signal and the video signal by the first compression method to form a normal stream (S300), and the second compression unit 20 compresses the audio signal and the video signal to the second compression method. Compression to form a turbo stream (S310).

The turbo stream compressed by the second compression method in the second compression unit 20 is RS encoded with parity added by the RS encoder 120 (S320), and in the TS processor 200 in the place holder maker 130. An area to which parity is added is generated (S330).

The turbo stream having the region to which the parity is added is interleaved by the interleaver 140 (S340) and input to the TS mux 150. The TS mux 150 configures a dual transport stream by multiplexing a normal stream and a turbo stream (S350).

Thereafter, the dual transport stream is input to the TS processing unit 200 and subjected to randomization, RS encoding, interleaving, turbo coding, trellis encoding, multiplexing, pilot insertion, VSB modulation, and RF conversion. Is sent through.

5 is a block diagram of a digital broadcast receiving apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 5, the digital broadcast receiver 2000 according to an exemplary embodiment of the present invention includes a demodulator 410, an equalizer 420, a first processor 430, and a second processor 440. .

The demodulator 410 detects and demodulates synchronization according to the synchronization signal added to the baseband signal of the dual transport stream received from the digital broadcast transmission apparatus 1000.

The equalizer 420 equalizes the demodulated dual transport stream to compensate for channel distortion due to multipath of the channel. The dual transport stream equalized by the equalizer 420 is provided to the first processor 430 and the second processor 440.

The first processor 430 restores normal stream data by processing a normal stream of the dual transport stream. The first processor 430 includes a Viterbi decoder 431, a first deinterleaver 432, an RS decoder 433, and a first derandomizer 434.

The Viterbi decoder 431 performs error correction on the normal stream of the equalized dual transport stream and decodes the error-corrected symbol to output a symbol packet.

The first deinterleaver 432 deinterleaves the decoded packet to reorder the distributed packets.

The RS decoder 433 corrects the error by resolving the deinterleaved normal stream packet.

The first derandomizer 434 derandomizes the ReedSolomon decoded normal stream packet to restore normal stream data.

Meanwhile, the second processor 440 recovers turbo stream data by processing a turbo stream of the dual transport stream. According to FIG. 3, the second processor 440 includes a turbo decoder 441, a second deinterleaver 442, a parity remover 443, a second reverse randomizer 444, a turbo demux 445, and the like. Laser decoder 446.

The turbo decoder 441 performs turbo decoding only on the turbo stream of the equalized dual transport stream. The turbo decoder 441 reconstructs the dual transport stream by inserting the turbo stream back into the dual transport stream when turbo decoding is completed.

The second deinterleaver 442 deinterleaves the reconstructed dual transport stream and rearranges the packets.

The parity remover 443 removes parity existing in the deinterleaved dual transport stream.

The second reverse randomizer 444 derandomizes the dual transport stream from which parity is removed.

Turbo DE-MUX 350 restores turbo stream data by demultiplexing the derandomized dual transport stream.

The erasure decoder 360 performs erasure decoding on the reconstructed turbo stream data. The transmitter 1000 generates an dual transport stream by inserting a turbo stream into a normal stream after performing erasure encoding for noise reduction. Accordingly, the erasure decoder 195 may improve the reception performance by removing noise of the turbo stream by performing erasure on the erase encoded turbo stream.

5 illustrates a digital broadcast receiver 2000 according to a preferred embodiment, and the structure of the receiver 2000 is not limited to this embodiment. For example, the second processor 440 may include only the turbo decoder 441, and may be configured to process the normal stream and the turbo stream in the first processor 430, respectively.

As described above, according to the present invention, a digital broadcast transmission apparatus, a turbo stream processing method thereof, and a digital broadcast system including the same according to the present invention are obtained by compressing a normal stream by MPEG-2 and a turbo stream by H.264. Turbo streams can be used more efficiently in current A-VSB systems.

That is, a similar level of quality broadcasting can be achieved at a smaller transmission rate, a better quality broadcasting can be achieved at the same rate as that of the conventional MPEG-2 method, and broadcast of similar quality on multiple channels can be realized. As a result, it is possible to expect the effect of reducing the operating costs of the broadcaster and maximizing profits.

While the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, it is usually in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications may be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (12)

A first compression unit configured to compress a predetermined audio signal and a video signal by a first compression method to form a normal stream; A second compression unit configured to compress a predetermined audio signal and a video signal by a second compression method to form a turbo stream; A TS component configured to multiplex the normal stream and the turbo stream to form a dual transport stream; And And a TS processor for robustly processing the dual transport stream transmitted from the TS configuration unit. The method of claim 1, The first compression scheme is a moving picture expert group group (MPEG-2). The method of claim 1, And the second compression method is H.264. The method of claim 1, The TS component, An RS encoder for RS encoding the configured turbo stream; A place holder maker for adding a parity insertion region to the RS encoded turbo stream; An interleaver for interleaving the turbo stream to which the parity insertion region is added; And And a TS mux for multiplexing the interleaved turbo stream and the configured normal stream. Compressing a predetermined audio signal and a video signal by a first compression method to construct a normal stream; Compressing a predetermined audio signal and a video signal by a second compression method to construct a turbo stream; Multiplexing the normal stream and the turbo stream to form a dual transport stream; And Robustly processing the configured dual transport stream; Turbo stream processing method of a digital broadcast transmission device comprising a. The method of claim 5, And the first compression method is MPEG-2. The method of claim 5, The second compression method is H.264 turbo stream processing method, characterized in that. The method of claim 5, Comprising the dual transport stream, RS encoding the configured turbo stream; Adding a parity insertion region to the RS encoded turbo stream; Interleaving the turbo stream to which the parity insertion region is added; And And multiplexing the interleaved turbo stream and the configured normal stream. A transmission device configured to multiplex the normal stream compressed by the first compression method and the turbo stream compressed by the second compression method to form a dual transport stream, and to process and output the dual transport stream with robustness; And And a receiving device which receives the output dual transport stream and decodes and restores the normal stream and the turbo stream, respectively. The method of claim 9, The first compression scheme is a moving picture expert group group (MPEG-2). The method of claim 9, And the second compression scheme is H.264. The method of claim 9, The transmitting device, A first compression unit for compressing a predetermined audio signal and a video signal by the first compression method to configure the normal stream; A second compression unit configured to form a turbo stream by compressing a predetermined audio signal and a video signal by the second compression method; A TS component configured to multiplex the normal stream and the turbo stream to form a dual transport stream; And And a TS processor for robustly processing the dual transport stream transmitted from the TS configuration unit.

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