RGB video as H.264/AVC's input

[krao]

Hi all,

I have used H.264/AVC for my research work before but with only YUV sequences as input. I am now in a situation where the input (intermediate result of my research) is in RGB format. I do not know how to use H.264/AVC to compress this.

Specifically, in my C program I do some processing and get results in an RGB format. I am not supposed convert this to YUV because of some research-related restrictions (comparison of results, etc).

1. So how do I create a RGB video file?
2. Is there a fixed format that H.264/AVC wants? Or can I just create a file using "fwrite" in C that contains RGB similar to how I would create a YUV 4:4:4 file?
3. Should the extension be .rgb for such a file?

Any help in this regards would be greatly appreciated ! Thank you!

[jagabo]

Most AVC encoders will use YUV with 4:2:0 subsampling (YV12) internally, and expect that as input. You can't just write out raw digital video without some kind of container organization*. Even if your encoder supports RGB as input you'll need a container. AVI is probably easiest if your source is constant frame rate.

http://fourcc.org/yuv.php#YV12

*Actually, you can write raw frames without a container but you'll need special handling to get that into the encoder.

[krao]

Thanks jagabo.

I think what I'll do is to use OpenCV to write the RGB arrays into an AVI file and then invoke the JM reference H.264/AVC encoder to compress it. The frame rate or processing is not of concern at this stage of my work -- currently I am only interested in the compression ratio and quantization effects owing to the nature of my input data.

Thanks !