KR20020058983A - Beat stream transferring method of a MPEG-4 CODEC - Google Patents

Abstract

PURPOSE: A method of transmitting an external bit stream of an MPEG-4 codec is provided to mount an MPEG-4 data bit stream having a low bit rate on a high-speed IEEE 1394 bus, thereby increasing a transmission speed per frame. CONSTITUTION: An IEEE 1394 protocol is composed of a serial bus management layer(1), an application layer(2), an SBP-2 layer(3), a transaction layer(4), an IEC 61883 layer(5), a link layer(6), and a physical layer(7). The link layer includes cycle control, packet transmission, and packet reception. The physical layer includes encoding/decoding, mediation, media, and an interface. A data bit stream of an MPEG-4 codec is loaded into the IEEE 1394 bus. The data bit stream is transmitted. A serial bus permits communication between nodes at a speed of 100Mbps to 400Mbps through shared physical media.

Description

Beat stream transferring method of a MPEG-4 CODEC

The present invention relates to a method for transmitting an external bit stream of an MPEG-4 codec. More specifically, an MPEG-4 standard data bit stream having a low bit rate of about 128 Kbps is mounted on a high-speed IEEE 1394 bus having a speed of 400 Mbps or more. The present invention relates to a method of transmitting an external bit stream of the MPEG-4 codec, which can increase the transmission rate per frame.

Stream generator output as an external data bit stream from a codec that conforms to the MPEG-4 standard of the Moving Picture Expert Group (MPEG), an international standardization organization for video signal encoding, which is under the auspices of the International Organization for Standardization and the International Electrotechnical Commission. The bit rate of Producer (SP) is currently defined as a low data rate of 128 Kbps.

This low bit rate with a bit rate of about 128 Kbps is suitable for video mobile phones. This is because the video mobile phone does not require high resolution and does not require a wide bandwidth. Therefore, a codec mounted in an IMT2000 video mobile phone transmits an external bit stream having a low data rate as described above.

1 is a state diagram related to VOP generation of an external bit stream of a conventional MPEG-4 codec, and FIG. 2 is a state diagram related to MB generation of an external bit stream of a conventional MPEG-4 codec, and the external data bits of the encoder part. It shows the process until the stream is created.

As shown in FIG. 1 and FIG. 2, the output value from the previous stage DCT / Q passes through VLC, and most of the bit stream for VOP or MB is output to SRAM. In addition, in case of data division in MPEG-4 standard, data is divided into DC, AC, or MV separately according to I-VOP or P-VP, not MB at once. Is output from the stream to the outside. Through this case, the value of the last generation stream is outputted serially by one bit to the outside, or in parallel by 8 bits or 16 bits.

However, these conventional low bit rate data bit streams are suitable for video mobile phones that do not require high resolution and do not require wide bandwidth, but are suitable for applications requiring high resolution and high sound quality such as digital cameras and HDTVs. There is an unsuitable problem.

An object of the present invention is to solve such a conventional problem, and by installing a data bit stream of MPEG-4 standard having a low bit rate of about 128 Kbps on a high speed IEEE 1394 bus having a speed of 400 Mbps or more, The present invention provides a method for transmitting an external bit stream of an MPEG-4 codec that can be enhanced.

1 is a state diagram related to VOP generation of an external bit stream of a conventional MPEG-4 codec.

2 is a state diagram related to MB generation of an external bit stream of a conventional MPEG-4 codec.

3 is a block diagram showing a protocol standard of the IEEE 1394 bus according to an embodiment of the present invention.

As a means for achieving the above object, the configuration of the present invention includes a serial bus management layer, an application layer, an SBP-2 layer, a transaction layer, an IEC 61883 layer, cycle control, packet transmission, and packet reception. In the protocol of the IEEE 1394 bus composed of a link layer and a physical layer for encoding and decoding, mediation, media, and interface, the method includes transmitting a data bit stream of MPEG-4 codec on the IEEE 1394 bus. Is done.

Hereinafter, the most preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the present invention. . Other objects, features, and operational advantages, including the object, operation, and effect of the present invention will become more apparent from the description of the preferred embodiment.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred examples to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment. However, various changes and modifications are possible within the scope without departing from the technical spirit of the present invention, as well as other equivalent embodiments.

As shown in FIG. 3, the configuration of a method for transmitting an external bit stream of an MPEG-4 codec according to an embodiment of the present invention includes a serial bus management layer 1, an application layer 2, and an SBP-2 layer ( 3) the transaction layer (4) and the IEC 61883 layer (5) and the link layer (6) for cycle control, packet transmission and packet reception, and the physical layer (7) for encoding and decoding, mediation, media and interfaces. In the protocol of the IEEE 1394 bus, the data bit stream of the MPEG-4 codec is carried on the IEEE 1394 bus and transmitted.

With the above configuration, the operation of the external bit stream transmission method of the MPEG-4 codec according to the embodiment of the present invention is as follows.

If you can have a wide bandwidth of about HDTV as well as the resolution required by a video mobile phone, if you output a low bit rate data bit stream of MPEG-4 standard on a high speed IEEE 1394 bus and output it, It can be improved by a few hundred times.

The present invention thus uses the IEEE 1394 bus to be used between the PC and the PC or between the PC and the HDTV. The IEEE 1394 bus is a bus mainly used for home networking, and if a data bit stream of an MPEG-4 standard codec is loaded on this bus, a system having a high data rate can be realized.

Of course, the low bit rate resolution required by video mobile phones currently requires an external bit rate of 128 Kbps in the MPEG-4 standard, but other applications such as digital cameras and HDTVs require high resolution and broadband in the MPEG-4 standard. By embedding the data bit stream into the IEEE 1394 bus, it is possible to provide a system having a high data rate. Accordingly, the data bit stream corresponding to MB or VOP as the contents of the data bit stream of the MPEG-4 standard is loaded on the data of the IEEE 1394 bus in serial or parallel, and high-speed data transmission is performed to a device requesting transmission.

As described above, when the MPEG-4 standard low bit rate data bit stream is loaded on a high speed IEEE 1394 bus and outputted, the following advantages can be obtained.

First, if multiple audio and video-related device systems are stuck on the IEEE 1394 bus, hot plugging supports that 1394 nodes can be connected to and disconnected from the IEEE 1394 bus without powering down when a new 1394 node is added. It is possible to configure a free topology using chains and branches. It is also advantageous that the termination required on a bus such as SCSI (SCSI) is unnecessary.

Secondly, high transmission rates can be provided. The IEEE 1394 bus is a hardware and software standard interface supporting 100 Mbps, 200 Mbps, and 400 Mbps per second to ensure bandwidth for real-time transmission of various high-definition and high-quality data.

Third, interoperability is possible between devices with different transmission rates, which facilitates overall system expansion. The IEEE 1394 bus is suitable for a network, which supports up to 63 node connections, which can be further extended by using bridges between the bus.

Fourthly, since the isochronous transmission method and the asynchronous transmission method are supported, the data transmission can be stably transmitted even under the load of multimedia data.

Among the features of the IEEE 1394 bus to be used in the present invention, the transmission speed and the IP over IEEE 1394 standard, which is currently an issue. The data bit stream corresponding to the MPEG-4 standard is loaded on the IEEE 1394 bus to adopt a method of transmitting data. The above standard for IP over IEEE 1394 specifies how to use the IEEE 1394 standard, a standard for high performance serial buses, for the transmission of datagrams of Internet Protocol version 4. That is, the method, data structure and code necessary for the above-mentioned purpose are defined, and additionally, a method for address resolution protocol and a multicast channel assignment protocol is defined.

Both are unique to serial buses. The IEEE 1394 standard is an interconnect bus conforming to ISO / IEC 13213: 1994, Control State Register (CSR) architecture. Serial buses now allow communication between nodes over shared physical media at speeds of 100 Mbps to 400 Mbps. Consumer electronics applications such as digital VCRs, stereo systems, televisions, and camcorders, and general desktop computer applications such as mass storage, printers, and tapes, all adopt the IEEE 1394 standard. Serial buses are unique in the connection to both the consumer and computer domains, and are expected to combine both sides of the device to form the basis of a home or small business network.

The Control Status Register (CSR) architecture is described as a memory-map address space that allows the serial bus to operate on a 64-bit fixed address scheme. 10 bits are allocated to the bus ID in the address area, and 6 bits are allocated for the physical ID of the node. On the other hand, the remaining 48 bytes of offset represent 256 terabytes of node address space. Conventionally, the structure of the control state register (CSR) divides the node's address space into two regions with different operating characteristics. OxFFFF F0000 The lower part, not including 0000, above it is expected to act as memory in response to read and write transactions. The upper part is the same as the traditional IO space. Control state registers have FIFO behavior that is customarily operated within this region. Within a 64-bit address, the 16-bit node ID (bus ID and physical ID) is similar to the network hardware address, but the IEEE 1394 node IDs vary and are reassigned when one or more nodes are added to or removed from the bus. The bus is activated.

As described above, in the embodiment of the present invention, an MPEG-4 standard data bit stream having a low bit rate of about 128 Kbps is mounted on a high speed IEEE 1394 bus having a speed of 400 Mbps or more, thereby increasing the transmission rate per frame. It is possible to provide a method for transmitting an external bit stream of an MPEG-4 codec having Such an effect of the present invention can be applied to various applications within the scope of the technical spirit of the present invention in the field of bit stream transmission.

Claims (2)

For serial bus management layer, application layer, SBP-2 layer, transaction layer, IEC 61883 layer, link layer for cycle control, packet transmission, packet reception, encoding and decoding, mediation, media and interface In the protocol of the IEEE 1394 bus composed of a physical layer, And transmitting a data bit stream of an MPEG-4 codec on the IEEE 1394 bus. The method of claim 1, The serial bus is a method of transmitting an external bit stream of an MPEG-4 codec, which allows communication between nodes at a speed of 100 Mbps to 400 Mbps through a shared physical media.