JP2009071526A - Video transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video transmission device capable of eliminating a delay difference between an HD output from an HD input and an HD output after upconversion from an SD input, and also reducing hardware. <P>SOLUTION: The video transmission device 1 includes an HD video input part 11. The frame delay of an HD video signal and an exchanger are eliminated, thereby using a frame buffer 13 previously arranged in the video transmission device 1 as a substitute for a frame delay function. Besides, an HD video output part 15 is used in place of the exchanger 25. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a video transmission apparatus which is used in, for example, a broadcasting station and handles a video signal of HD (High Definition) format and a video signal of SD (Standard Definition) format.

  In the terrestrial broadcasting system, digital broadcasting has been started. In this digital broadcasting, 1125-line high-definition television broadcasting (hereinafter referred to as HD) and multi-channel NTSC (525-line) television are used. Mixed broadcasting with John Broadcasting (hereinafter referred to as SD) is possible.

In this HD / SD mixed broadcasting, SD input → SD output and HD input → HD output are in a one-to-one relationship, which is expensive in terms of facility expansion. Therefore, from the viewpoint of facility reduction, a sending apparatus that converts an SD format video signal into an HD format video signal and sends it out has also been proposed (for example, Patent Document 1).
JP 2006-203821 A.

  By the way, in the above transmission apparatus, a delay difference of 1 frame occurs between HD input → HD output and SD input → up-conversion → HD output, and a frame delay is required for phase adjustment.

  Accordingly, an object of the present invention is to eliminate the delay difference between the first system video input → first system video output and the second system video input → up-conversion → first system video output, and also to reduce hardware. It is to provide a video transmission device to obtain.

  In order to achieve the above object, a video transmission apparatus according to the present invention includes a first input unit for inputting a video signal of a first system having a frame structure, and a second input having a frame structure and different from the first system. A second input unit for inputting a video signal of the system, and a second system for temporarily storing the video signal of the first system input by the first input unit and input by the second input unit. A frame buffer that temporarily holds a video signal; an output unit that outputs a first type video signal; and a second type video signal that is input from the second input unit to the frame buffer. When the second format video signal of the frame is read out, converted to the first format video format and input to the output unit, the first format video signal is input from the first input unit to the frame buffer. Thailand From the frame buffer after a delay time required from ring to the format conversion process is obtained by such a control unit for inputting the output unit reads the video signal of the first type.

  According to this configuration, the first input unit is provided in the apparatus, and the frame delay function of the video signal of the first method is shared by the already provided frame buffer. Accordingly, there is no need to provide a separate frame delay unit or switch, and the frame delay unit is shared with the frame buffer already provided in the apparatus. It is possible to provide a video transmission device capable of eliminating the delay difference between the system video output and the second system video input → up-conversion → first system video output.

  As described above in detail, according to the present invention, the delay difference between the first system video input → first system video output and the second system video input → up-conversion → first system video output is eliminated, and hardware Can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of an embodiment of a video transmission apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a video transmission device, which includes an HD video input unit 11, an SD video input unit 12, a frame buffer 13, a conversion unit 14, and an HD video output unit 15.

  The HD video input unit 11 is an interface for inputting an HD format video signal (hereinafter referred to as an HD video signal). The SD video input unit 12 is an interface for inputting an SD format video signal (hereinafter referred to as an SD video signal).

  The HD video signal input to the HD video input unit 11 is sent to the frame buffer 13 and stored in the frame buffer 13. The HD video signal stored in the frame buffer 13 is read by the conversion unit 14 after a delay time corresponding to one frame from the time of input to the frame buffer 13 and sent to the HD video output unit 15. The HD video output unit 15 is an interface for outputting an HD video signal.

  The SD video signal input to the SD video input unit 12 is sent to the conversion unit 14 and stored in the frame buffer 13 by the conversion unit 14. The conversion unit 14 reads out one frame of the SD video signal stored in the frame buffer 13, reads out and refers to the SD video signal of the frame before and after the frame, and converts the SD video signal into the HD video based on the reference result. The signal is converted into a signal and output to the HD video output unit 15.

  By the way, in this embodiment, the HD video input unit 11 is provided with the gate unit 111, and the SD video input unit 12 is provided with the gate unit 121. The gate unit 111 prohibits the output of the HD video signal to the frame buffer 13 when an SD video selection instruction signal is sent from a higher-level device (not shown).

  Further, the gate unit 121 prohibits the output of the SD video signal to the conversion unit 14 when an HD video selection instruction signal is sent from the host device.

The operation of the above configuration will be described below with a specific example.
As shown in FIG. 2, in the image conversion apparatus 20 that converts an SD video signal into an HD video signal, it is necessary to refer to the images of the frames before and after the image in the calculation, so the video data of the past frames is stored. The frame buffer 21 to be used is necessary, and the calculation causes a delay of one frame between the SD video input unit 22-the conversion unit 23-the HD video output unit 24.

  Therefore, in a mixed HD / SD broadcasting system, a delay difference of one frame is generated between the output of HD video input as it is and the output of HD video output after up-converting the SD video input. 25 and adjusting the phases of the two, it is necessary to provide a switch 26 in the subsequent stage to unify the HD video output.

  Thus, in the present embodiment, the HD video input unit 11 is provided in the video transmission device 1 corresponding to the previous image conversion device 20, and the frame buffer 13 used for up-conversion calculation is used as a frame delay when HD video is input. Used to generate a delay of one frame between HD video input → HD video output. As a result, there is no delay difference between the output for outputting the HD video as it is and the output for up-converting the SD video input to output the HD video.

  Accordingly, the frame delay 25 that has been conventionally required is not necessary, and the HD video output can be unified in the video transmission device 1.

  As described above, in the above-described embodiment, the video transmission device 1 is provided with the HD video input unit 11, the frame delay 25 of the HD video signal and the switch 25 are deleted, and the frame delay function is already provided in the video transmission device 1. The frame buffer 13 is used as a substitute. The switch 25 is also replaced by the HD video output unit 15.

  Accordingly, it is not necessary to separately provide the frame delay 25 and the switch 26, and the frame delay 25 is shared by the frame buffer 13 already provided in the video transmission device 1, so that the video transmission device 1 is relatively A simple and small configuration can be achieved, and a delay difference between HD video input → HD video output and SD video input → up-conversion → SD video output can be eliminated.

  Further, in the above-described embodiment, the present invention can be similarly implemented when handling video signals other than HD and SD formats.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The block diagram which shows the structure of one Embodiment of the video transmission apparatus which concerns on this invention. The block diagram which shows the structure of the image conversion apparatus considered before.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Video transmission apparatus, 11 ... HD video input part, 12, 22 ... HD video input part, 13, 21 ... Frame buffer, 14, 23 ... Conversion part, 15, 24 ... HD video output part, 20 ... Image conversion apparatus , 25 ... frame delay, 26 ... switch, 111, 121 ... gate part.

Claims (3)

A first input unit for inputting a video signal of a first method having a frame structure;
A second input unit for inputting a video signal of a second system different from the first system in a frame structure;
A frame buffer that temporarily holds a first-type video signal input from the first input unit and temporarily holds a second-type video signal input from the second input unit;
An output unit for outputting a video signal of the first method;
When a second format video signal is input from the second input unit to the frame buffer, a plurality of frames of the second format video signal are read from the frame buffer and converted into a first format video format. When the first format video signal is input from the first input section to the frame buffer, the first format is output from the frame buffer after the delay time required for the format conversion processing from this input timing. And a control unit that reads the video signal and inputs the video signal to the output unit. The first input unit includes gate means for stopping output of the video signal of the first system to the frame buffer when the input of the video signal of the second system is selected.
2. The second input unit includes gate means for stopping output of the video signal of the second format to the frame buffer when the video signal of the first format is selected as input. Video transmission device. The video signal of the first system is a video signal of 1125 line system (HD (High Definition) format), and the video signal of the second system is a video signal of 525 line system (SD (Standard Definition) format). The video transmission device according to claim 1.

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