JPH0955934A - Picture/sound compression device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the whole number of chips and the number of parts in a camera and VTR with built-in CODEC, and to make a picture/sound compression device small in size and light in weight by providing a memory controller for picture compression and a memory controller for a communication function on the same semiconductor substrate of CODEC-LSI. SOLUTION: A video signal from a camera part 101 is inputted to a memory chip 103 via the memory controller 102 constituted in CODEC-LSI100. The information is returned to CODEC-LSI100 at appropriate time, is encoded by a compression processing circuit 104 and is inputted to MPU 107 via a system bus 106. In MPU 107, data is stored in a recording medium at the time of recording, and the signal is returned to CODEC-LSI100 after a prescribed processing is added in the case of transmission. The signal is converted by a parallel/serial converter 112 provided for a communication part 109 and is outputted via a FIFO memory 111 controlled by the memory controller 110.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device having an image compression function, and more particularly to an image compression device having a function of converting compressed image information into a bit stream and outputting the bit stream.

[0002]

2. Description of the Related Art Due to the progress of image compression technology and LSI technology, the H.264 standard recommended by ITU_T. H.261, MPEG I, II, etc. standard image information compression / expansion device (encoder /
Decoders) are becoming popular.

Generally, these image information compression / decompression devices are CO
DEC and signal processing LSI for this purpose are codec
_LSI is being promoted as one of multimedia key devices to reduce the size and cost of CODEC_LSI.

The information compressed by the CODEC is stored in a storage medium such as an optical disk in the form of a bit stream of compressed data, or is stored in an ISDN line or ATM.
It is considered to be transmitted and used by using a communication network or the like. Therefore, in ITU_T, H.221 recommendation and M
Part 1 of the PEG II Recommendation provides for storage or transmission. Especially, regarding the latter, Vol.
9 No. 5 (April 1995 issue) pp. 480-489 Yoshimura et al.

[0005]

When the above-mentioned CODEC is built in an AV device such as a camera or a VTR, the compressed information is used for the processing such as the exchange and movement of the video and audio information which is conventionally performed by transmitting and receiving an analog signal. It is natural to do this by bitstream communication.

Therefore, the AV device having the CODEC function outputs the compressed video information to another CODEC device together with the compression / expansion function of the image information, and conversely, the bit stream input from the other CODEC device. It is desirable to have a communication function so that the video and audio information can be expanded and reproduced.

By the way, the bit stream used for the communication between such devices is other than the information necessary for the CODEC processing of the image / audio information as shown in the conventional example, depending on the type of the transmission path, the reliability, the connection form and the like. Of the sending end,
In most cases, the address information of the receiving end is added and transmitted, and of course, these must be managed separately from the information necessary for CODEC processing.
Therefore, the CODEC device having a communication function with the outside of the device has (1) a CODEC part, (2) a part for generating and interpreting a bitstream input / output to / from the device, and (3) a communication part for actually inputting / outputting a bitstream. Three parts are required, but conventionally each of these parts, especially (2)
In contrast to (3), (1) is configured independently, and sufficient consideration has not been given to size reduction and weight reduction.

[0008]

In the above-mentioned CODEC device, that is, in the CODEC_LSI incorporated therein, a memory and a memory controller used for orthogonal transformation of image data are essential. Also in the communication function,
A memory and a memory controller are also required for real-time communication at a bit rate different from the bit rate of the bit stream generated by CODEC, and to cope with the jitter generated on the transmission path for some reason. It is realized by a similar semiconductor process.

Therefore, in the present invention, any one or more of the following means are used.

(1) Both a memory controller for image compression and a memory controller for communication function are provided on the same semiconductor substrate of CODEC_LSI.

(2) On the same semiconductor substrate of CODEC_LSI, both a memory for image compression and a memory for communication function are generated.

(3) A part of the address of the memory chip connected to the CODEC_LSI is used for compression, and the other part is used for communication.

(4) A memory controller for image compression, a memory controller for communication function, and a memory for communication function are generated on the same semiconductor substrate of CODEC_LSI.

[0014]

If any one or more of the above means are used, it is not necessary to separately configure the compression section and the communication section.
It is possible to reduce the total number of chips of AV devices such as cameras and VTRs with a built-in EC, and achieve size and weight reduction. Further, if the compression unit and the communication unit are driven by the clock pulse generated by the common oscillator in the above configuration, it is not necessary to provide an independent oscillator, and the size and weight can be reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In this embodiment, an example will be described in which the image compression device has a serial signal transmission / reception function.

First, the process of compressing image information and transmitting the compressed information to the outside of the apparatus will be described with reference to FIG.

The video signal output from the camera unit 101 is input to the memory chip 103 via the memory controller 102 included in the CODEC_LSI 100 (A). This information will be returned to CODEC_ at the appropriate time.
After being returned to the LSI (B) and encoded (compressed) by the compression processing circuit 104, M is passed through the system bus 105.
It is input to the PU 106 (C). When recording this, the MPU adds information necessary for recording, such as recording time, and stores it in the recording medium 107 (D). When transmitting this, for example, a communication packet of a certain length is transmitted. After generating and adding processing such as dividing and inserting the encoded signal into the data part, the signal is sent to the CO via the system bus.
Return to DEC_LSI (E). In the CODEC_LSI, the parallel-serial converter 1 provided in the communication unit 109
After P / S conversion by 12, the data is output via the FIFO memory 111 controlled by the memory controller 110.

Next, the process of receiving the compressed image information and decompressing (decoding) it will be described with reference to FIG.

In the case of reception, on the contrary, the FIFO buffer 11
After inputting at 1, it is converted to serial-parallel and input to the MPU via the system bus (F). The MPU interprets this received signal and, for example, if it is received information including compressed video signal information, inputs the portion related to this to the memory chip 103 via the system bus and memory controller (H)
After that, it is also returned to the CODEC_LSI at an appropriate timing via the memory controller (I) and decoded by the expansion processing circuit 105.

With the above processing, the control of the memory chip and the control of the communication FIFO memory are controlled by CODEC_.
Each memory controller 10 configured in the LSI
2 and 110, both are driven by the clock pulse generated from the oscillator 103 connected to the CODEC_LSI.

With this configuration, it is not necessary to separately provide the communication memory, its controller, and the like, separately from the CODEC_LSI, and it is not necessary to install an independent oscillator. Therefore, it is not necessary to install a CODEC in an AV such as a camera or a VTR.
It is possible to reduce the total number of chips and parts of the device, and achieve size and weight reduction.

As described above, in this example, the communication FIF is used.
Although the O memory is configured in CODEC_LSI and the compression processing memory is a separate chip, this configuration is used for communication FI.
The FO memory is generally of the order of kilobits, whereas the memory for compression processing needs to be on the order of megabits. To CODEC_L
It is also possible to configure on SI.

Further, when packetized bitstream information is transmitted at high speed, C is added at the final position of the packet.
It is generally performed to insert and transmit error detection information such as RC (Cyclic Redunduncy Check) bits,
A circuit for this may be provided in the communication section of the CODEC_LSI. For example, the CRC error detection circuit can be realized by a simple feedback shift register and an exclusive OR circuit as is generally known.

Another embodiment of the present invention will be described above with reference to FIG. The process of compressing image information and transmitting the compressed information to the outside of the apparatus will be described with reference to FIG.

In this embodiment, a part of the address of the memory chip connected to the CODEC_LSI is used for compression and the other part is used for communication.

In the above embodiment, an example of constructing the communication FIFO memory on the CODEC_LSI has been described. In this embodiment, a part of the memory address of the chip different from the CODEC_LSI is used for compression / expansion, The other part is used for communication.

The video signal output from the camera unit 201 is input to the memory chip 203 via the memory controller 202 formed in the CODEC_LSI 200. Here, the memory chip has an address area X for compression / expansion in advance. Is provided, and input is performed in this area (A). This information will be returned to CO at the appropriate time.
The data is returned to DEC_LSI (B), encoded (compressed), and then input to the MPU 207 via the system bus 206. When recording this, the MPU adds information necessary for recording such as recording time and stores it in the recording medium 208, and when transmitting this, for example, generates a communication packet of a certain length, After adding processing such as dividing and inserting the encoded signal to the data portion, the signal is returned to the CODEC_LSI via the system bus again. In the CODEC_LSI, the signal is written again to the communication address area Y of the memory chip 203, which is predetermined and does not match the compression / expansion area, via the memory controller 202, and then read at a frequency suitable for communication.

[0028]

According to the present invention, the compression / expansion memory, the communication memory, and their controllers are provided in the CODEC.
It is not necessary to provide it separately from _LSI, and the total number of chips of AV equipment such as cameras and VTRs with built-in CODEC,
The number of parts can be reduced and the size and weight can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image compression / decompression device according to an embodiment of the present invention.

FIG. 2 is a block diagram of an image compression / decompression device according to another embodiment of the present invention.

[Explanation of symbols]

 100: CODEC-LSI, 101: camera unit, 102: memory controller, 103: memory, 104: compression processing circuit, 105: decompression processing circuit, 106: system bus, 107: MPU, 108: storage medium, 109: communication unit Reference numeral 110: memory controller 111: FIFO memory 112: parallel-serial converter 113: oscillator

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Chiba 1410 Inada, Hitachinaka City, Ibaraki Prefecture, Hitachi, Ltd., Personal Media Equipment Division (72) Inventor Hiroyasu Otsubo 1410 Inada, Hitachinaka City, Ibaraki Hitachi, Ltd. Personal Media Equipment Division (72) Inventor Yoshimichi Kudo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Multimedia System Development Headquarters

Claims (3)

[Claims] 1. An image-sound compression apparatus having a function of compressing or expanding image or sound information, and a function of communicating the compressed image or sound information with the outside of the apparatus. An image / sound compression apparatus comprising a control circuit for communication with the outside of the apparatus or a communication buffer memory on the same semiconductor substrate as an LSI for decompression. 2. An image and sound compression system according to claim 1, wherein the information communication circuit, the transmission error detection or error correction circuit related to the information communication, and the image and sound data compression or expansion circuit are formed on the same semiconductor substrate. apparatus. 3. A CO for compressing and expanding image or audio information.
In a video / audio compression apparatus equipped with a circuit for realizing a DEC function and a circuit for realizing a function capable of communicating compressed image or audio information with the outside of the apparatus, at least a communication circuit for communicating with the outside of the apparatus is at least 1 A clock pulse supplied to a part and a clock pulse supplied to at least a part of a circuit for realizing the CODEC function,
A video / audio compression device characterized in that it is a clock pulse generated from a common transmitter.