[UVC] Data sequence for YUY2 format

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HuYa_4249091
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Hi, I want to check data sequence for YUY2 format by UVC on Windows. Is it same as the following sequence which I found ?

YUV422.JPG

Any help will be highly appreciated!

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JayakrishnaT_76
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Hello,

UVC supports both of the following data sequences for 4:2:2 formats:

1. U0, Y0, V0, Y1,...

2. Y0, Y0, Y1, V0,...

Please refer to the Section 4:2:2 formats, 16 bits per pixel of the following document which already mentions this:

https://docs.microsoft.com/en-us/windows/win32/medfound/recommended-8-bit-yuv-formats-for-video-rend...

Best Regards,
Jayakrishna

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4 Replies
JayakrishnaT_76
Moderator
Moderator
Moderator
First question asked 1000 replies posted 750 replies posted

Hello,

UVC supports both of the following data sequences for 4:2:2 formats:

1. U0, Y0, V0, Y1,...

2. Y0, Y0, Y1, V0,...

Please refer to the Section 4:2:2 formats, 16 bits per pixel of the following document which already mentions this:

https://docs.microsoft.com/en-us/windows/win32/medfound/recommended-8-bit-yuv-formats-for-video-rend...

Best Regards,
Jayakrishna

Dear Jayakrishna:

Thanks for your professional reply!

I want to check the sequence for NV12 further. According to the link you provided:

NV12-2.JPG
Q1: What is the meaning for "even number"? Does it only mean: if the image resolution is 1920 * 1080, 1080 is the "total lines", and the "total lines" is even number?

Q2: If image resolution is 6 * 4, the sequence data shall be the following description for Windows?

NV12 example.JPG

Thanks!

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JayakrishnaT_76
Moderator
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First question asked 1000 replies posted 750 replies posted

Hello,

As you might be knowing, FX3 acts as a bridge between the image senor and the host. It just forwards the data received from the image sensor to the host. FX3 does not perform any format conversions. Any format conversion should be done by adding an FPGA between FX3 and the image sensor.

Please find my comments to your questions below:

1. We could not find any information on what exactly is meant by "even number" in the NV12 section of the link shared before. Can you please try to get the comments from Microsoft regarding this statement?

2. Yes, the sequence shown is correct. In the NV12 case the intensity (Y) data is stored as 8 bit samples, and the colour (Cr, Cb) information as 2x2 subsampled image, this is otherwise known as 4:2:0. The Y data is stored in one plane, the Cr and Cb channels are  interleaved in another plane.

Best Regards,
Jayakrishna


Dear Jayakrishna:


As you might be knowing, FX3 acts as a bridge between the image senor and the host. It just forwards the data received from the image sensor to the host. FX3 does not perform any format conversions. Any format conversion should be done by adding an FPGA between FX3 and the image sensor.

Thank you for your reminder. I knew that!


1. We could not find any information on what exactly is meant by "even number" in the NV12 section of the link shared before. Can you please try to get the comments from Microsoft regarding this statement?


I've posted the question to MS. If I get any reply, I'm going to share here.

Thanks a lot for your professional help!
Hughes

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