h264 lossless coding

Question

Is it possible to do completely lossless encoding in h264? By lossless, I mean that if I feed it a series of frames and encode them, and then if I extract all the frames fro

Answer 1

I don't know your requirements for compression and decompression, but a general purpose archiver (like 7-zip with LZMA2) should be able to compress about as small or, in some cases, even significantly smaller than a lossless video codec. And it is much simpler and safer than a whole video processing chain. The downside is the much slower speed, and that you have to extract before seeing it. But for images, I think you should try it.

There is also lossless image formats, like .png.

For encoding lossless RGB with x264, you should use the command line version of x264 (you can't trust GUIs in this edge case, they will probably mess-up) r2020 or newer, with something like that:

x264 --qp 0 --preset fast --input-csp rgb --output-csp rgb --colormatrix GBR --output "the_lossless_output.mkv" "someinput.avs"

Any losses/differences between the input and output should be from some colour space conversion (either before encoding, or at playback), wrong settings or some header/meta-data that was lost. x264 don't supports RGBA, but RGB is ok. YUV 4:4:4 compression is more efficient, but you will lose some data in colour space conversion as your input is RGB. YV12/i420 is much smaller, and by far the most common colour space in video, but you have less chroma resolution.

More information on x264 settings: http://mewiki.project357.com/wiki/X264_Settings

Also, avoid lagarith. It uses x87 floating point... and there are better alternatives. http://codecs.multimedia.cx/?p=303 http://mod16.org/hurfdurf/?p=142

EDIT: I don't know why I was donwvoted. Please leave a comment when you do that.