JP3060939B2 - Heterogeneous video system compatible encoding device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image encoding / decoding apparatus. 2. Description of the Related Art FIG. 4 is a block diagram showing a configuration of a transmission side and a reception side in a conventional image coding transmission apparatus for the same video system. In the figure, reference numeral 2 denotes an A / D converter for converting an input video signal 1 into a digital image signal 3, and reference numeral 4 denotes a Y / C separator for separating a Y component of a luminance signal and a C component of a chrominance signal. Signal 5 is sent. Reference numeral 6 denotes a transmitting side encoding / decoding circuit which performs encoding / transmission processing on an image signal, and sends out encoded information 7. 8 is a digital transmission line,
Reference numeral 9 denotes a receiving side encoding / decoding circuit which reproduces an image signal from the encoded information 7, and sends out an image reproduction signal 10. 11
Is a Y / C combiner that combines the luminance signal Y component and the color difference signal C component, and sends out a Y / C combined signal 12. Reference numeral 13 denotes a D / A converter that converts the Y / C combined signal 12 into an analog output signal 14. [0003] Next, the operation of the conventional image encoding and transmitting apparatus shown in FIG. 4 will be described. Now, in the input video signal 1 on the transmission side, 30 frames per second in the NTSC system, 525 horizontal scanning lines per frame, 525 horizontal scanning lines per frame in the PAL or SECAM system, 625 horizontal scanning lines per frame It is. The same applies to the analog output signal 14 on the receiving side. First, on the transmission side, an input video signal 1 is converted by an A / D converter 2 into a digital image signal 3 excluding the horizontal synchronization and vertical synchronization parts.
The luminance signal Y component and the color difference signal C component are separated by the Y / C separator 4. Next, in the transmitting side encoding / decoding circuit 6,
Image encoding is performed on horizontal (M is a positive integer) pixels and vertical (L is a positive integer) pixels in the horizontal and vertical directions (L is a positive integer) as the encoding target range of the Y / C separated signal 5 by the Y / C separator 4. Then, the encoded information 7 is sent to the digital transmission line 8. At this time, for the L pixels in the vertical direction, only one field in one frame is to be coded, and the number of pixels to be coded is limited by sampling lines at equal intervals. The same applies to the M pixels in the horizontal direction. On the other hand, on the receiving side, the number of M pixels in the horizontal direction and the number of L pixels in the vertical direction are obtained from the encoded information 7 received from the digital transmission path 8 by the encoding / decoding circuit 9 on the receiving side.
An image reproduction signal 10 having the number of pixels is generated, and a Y / C synthesizer 11
Then, the luminance signal Y component and the color difference signal C component are combined while performing linear interpolation in the horizontal and vertical directions, and the Y / C combined signal 12 is converted by the D / A converter 13 to output an analog output signal 14. . It should be noted that a frame that is lost due to dropped frames repeatedly outputs the immediately preceding image reproduction signal. [0004] Since the above-mentioned conventional image coding and transmitting apparatus is configured as described above, when the video system is different between the transmitting side and the receiving side, the image on the transmitting side and the receiving side are transmitted. Since the ratio of the image portion to the entire screen in the vertical direction differs from that of the image, the reproduced image is distorted, so that the transmission side or the reception side requires a new video format conversion device. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a video coding system compatible with different video systems capable of performing video communication between different video systems without adding the video system conversion device to the outside. The purpose is to: According to the present invention, there is provided an encoding apparatus compatible with different types of video systems , wherein one frame has five horizontal scanning lines.
25 transmission using NTSC video system
From the side, unlike the NTSC system, one frame of horizontal
PAL or SECAM video with 625 scanning lines
To perform image coding transmission to the receiving side using the image method
A different video format compatible encoding apparatus,
The side converts the NTSC image signal into a predetermined format
First format conversion means for converting the first format
Predetermined format converted by format converter
Encoding processing for the image signal of
For transmitting an image signal of the predetermined format
Wherein the receiving side transmits from the transmitting side.
The encoded image signal of the predetermined format
Decoding means for receiving and decoding, and the decoding means
The image signal of the predetermined format decoded by
Convert to AL or SECAM video signal
Second format conversion means.
You. On the contrary, the horizontal scanning line of one frame has six lines.
Use 25 PAL or SECAM video system
From the transmitting side, the PAL or SECAM method
Is different from NT in which one frame has 525 horizontal scanning lines.
Image encoding transmission to the receiving side using the SC video system
This is a heterogeneous video system compatible encoding device that performs
Therefore, the transmitting side transmits the PAL or SECAM image.
A first format for converting an image signal into a predetermined format;
Conversion means and the first format converter.
The encoding process is performed on the converted image signal of the predetermined format.
The predetermined format encoded to the receiving side.
Encoding means for transmitting the image signal of
Side transmits the coded predetermined information transmitted from the transmitting side.
Decoding means for receiving and decoding an image signal of a format
And the predetermined format decoded by the decoding means.
The image signal of the mat is converted to an image of the NTSC video system.
And second format conversion means for converting the signal into a signal.
Things. FIG. 1 is a block diagram showing a configuration of a transmitting side and a receiving side in a heterogeneous video system compatible coding apparatus according to an embodiment of the present invention. This is the same as that of the conventional example shown in FIG. In the figure,
Reference numeral 15 denotes a transmitting-side format converter, which sends out a format-converted signal 16. Reference numeral 17 denotes a transmission-side frame memory, which transmits a frame signal 18 to be encoded. 1
Reference numeral 9 denotes a receiving-side frame memory that stores the image reproduction signal 10 and sends out the image reproduction signal 20. Reference numeral 21 denotes a receiving-side format converter, and a format-converted signal 22
Is sent. FIG. 2 is an explanatory diagram showing an example of transmission-side format conversion when the transmission-side video system in the heterogeneous video system compatible encoding apparatus of FIG. 1 is the PAL or SECAM system;
FIG. 3 is an explanatory diagram showing an example of the receiving-side format conversion in the case where the receiving-side video system in the heterogeneous video system compatible encoding apparatus of FIG. 1 is the PAL or SECAM system. [0008] In this heterogeneous video system compatible coding apparatus, as a format converter, when the video system is the PAL or SECAM system, the sampling on the vertical line is coarser than in the case of the NTSC system on the transmission side. By increasing the number of line interpolations in the vertical direction in the case of the PAL or SECAM system on the receiving side as compared with the case of the NTSC system, the ratio of the image to the entire screen in the vertical direction on the transmitting side and the receiving side is matched. To Next, the operation of the encoding apparatus compatible with different video systems according to the embodiment of the present invention shown in FIG. 1 will be described. For the Y / C separated signal 5 on the transmitting side, the input side video signal 1
In the case of the SC system, starting from a predetermined line, simply sample L lines from n × L (n, L are positive integers and n × L is smaller than 525) lines of the image portion. On the other hand, in the case of the PAL or SECAM method, the number of horizontal scanning lines in one frame is 625, which is larger than that in the NTSC method. Generate a book line.
FIG. 2 shows an embodiment of the format conversion on the transmission side when the input video signal 1 is in the PAL or SECAM system. After the format-converted signal 16 is once stored in the transmission-side frame memory 17, it is read out as the encoding target frame signal 18 in accordance with the encoding processing timing of the transmission-side encoding / decoding circuit 6. The encoded information 7 sent from the transmitting-side encoding / decoding circuit 6 is transmitted to a digital transmission line 8. On the other hand, the image reproduction signal 10 reproduced by the reception-side encoding / decoding circuit 9 is stored in the reception-side frame memory 19 and then read out as an image reproduction signal 20 for each frame cycle of the reception-side video system. At this time, the frame dropped by the transmission side encoding process or the transmission side
For a frame that is missing when the receiving side is the NTSC system in the case of the L or SECAM system, the immediately preceding image reproduction signal 20 is repeatedly read. Next, when the receiving-side video system is the NTSC system, the receiving-side format converter 21 performs linear interpolation on the L lines of the image reproduction signal 20 to generate the n × L lines, PA
In the case of the L or SECAM method, in addition to the above linear interpolation, an interpolation is further performed at a ratio of one to five to obtain n × L × 1.2
(N × L × 1.2 is a positive integer) lines are generated.
FIG. 3 shows an embodiment of the format conversion on the receiving side when the receiving side video system is the PAL or SECAM system. The format-converted signal 22 that has been format-converted by the receiving-side format converter 21 is output to the Y / C combiner 11, and the D / A converter 11 performs D / A conversion after combining the luminance signal Y component and the color difference signal C component. Then, the analog output signal 14 is output in the receiving side video system. In the above embodiment, the case where the number of pixels to be encoded in the encoding / decoding circuit is fixed has been described, but the number and range of the pixels to be encoded can be switched by the format converter. According to the present invention, as described above , NTS
Video format between C system and PAL or SECAM system
Different types of video that send image signals from the sender to the receiver with different formulas
In a system compatible encoding device, the transmitting
A first method for converting an image signal of an image system into a predetermined format
Format conversion means and image signal of predetermined format
Encoding means for performing encoding processing on the
On the receiving side, an image in a predetermined format from the transmitting side
Decoding means for receiving and decoding the signal, and the decoded
The image signal of the predetermined format is converted into the image of the video system on the receiving side.
A second format converter for converting the signal into a signal;
Code for a given format image signal.
Encoding and decoding means for encoding and decoding
If one type of encoding / decoding circuit having functions is prepared, transmission
Both the receiver and the receiver can use the encoding / decoding circuit,
This is an excellent effect that an apparatus can be configured at low cost, and an extremely versatile video-compatible coding apparatus that can perform video communication between different video schemes can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a transmission side and a reception side in a heterogeneous video system compatible encoding apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing an example of transmission-side format conversion when the transmission-side video system in the heterogeneous video system compatible encoding apparatus in FIG. 1 is the PAL or SECAM system. FIG. 3 is an explanatory diagram showing an example of receiving-side format conversion when the receiving-side video system in the heterogeneous video system compatible encoding apparatus in FIG. 1 is the PAL or SECAM system. FIG. 4 is a block diagram showing a configuration of a transmission side and a reception side in a conventional image encoding transmission apparatus between the same video systems. [Explanation of Code] 1 Input video signal 2 A / D converter 3 Digital image signal 4 Y / C separator 5 Y / C separated signal 6 Transmission side coding / decoding circuit 7 Coded information 8 Digital transmission path 9 Reception Side encoding / decoding circuit 10, 20 Image reproduction signal 11 Y / C combiner 12 Y / C combined signal 13 D / A converter 14 Analog output signal 15 Transmission side format converter 16, 22 Format converted signal 17 Transmission Side frame memory 18 Encoding target frame signal 19 Receiving side frame memory 21 Receiving side format converter.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N ^7/ 00-7/01

Claims (1)

(57) [Claims] NTSC with 525 horizontal scanning lines per frame
From the transmitting side using the video system, the NTSC
Unlike the method, one frame has 625 horizontal scanning lines.
Receiving using a PAL or SECAM video system
Different video systems that perform image coding transmission to the receiving side
A transcoding device, wherein the transmitting side converts the NTSC image signal into a predetermined format.
A first format converter for converting the data and a predetermined format converted by the first format converter.
After encoding the image signal in the
And sends the encoded image signal of the predetermined format to the receiving side.
Has encoding means for signal, the said receiving side, the predetermined Four coded transmitted from the transmitting side
Decoding means for receiving and decoding the image signal of the mat; and the predetermined format decoded by the decoding means.
Video signal of the above PAL or SECAM system
Format conversion means for converting the image signal into an image signal
And a heterogeneous video system compatible encoding apparatus characterized by having
Place. 2. PAL or 625 horizontal scanning lines per frame
From the sender using the SECAM video system,
Unlike the PAL or SECAM method, one frame
NTSC video system with 525 horizontal scanning lines
The difference is that image encoding transmission is performed to the receiving side
A transmitting device, wherein the transmitting side converts the image signal of the PAL or SECAM system into a predetermined format.
First format conversion means for converting the data into a format, and a predetermined format converted by the first format converter.
After encoding the image signal in the
And sends the encoded image signal of the predetermined format to the receiving side.
Has encoding means for signal, the said receiving side, the predetermined Four coded transmitted from the transmitting side
Decoding means for receiving and decoding the image signal of the mat; and the predetermined format decoded by the decoding means.
Image signal of the NTSC video system
And a second format conversion means for converting to a different video format compatible encoding device.
Place.