Lossless ffmpeg conversion/encoding

Question

I'm looking for the best in quality when converting videos.

I only want to use lossless audio and video encoders and a good container.

How do I enable lossless x264 vcodec for ffmpeg?

I currently use ffmpeg -i "inputvideo" -s 1280x720 -ar 48000 -threads 4 -vcodec libx264 -acodec copy -dsur_mode 2 -ac 6 "outputvideo720p.mkv"

I plan on using flac for the acodec by am unsure because I don't want to use quality if it switches to 16-bit instead of 24-bit

Solution

You can use x264 in lossless manner I think. As in here and here use these flags for ffmpeg:

ffmpeg -i input.avi -c:v libx264 -qp 0 output.mkv

In case you couldn't load libx264, remove ffmpeg and install from source with x264 enabled. Here is how to.

Comments

[Marc Brown]

I'm currently using ffmpeg's FFV1 loss-less codec. Even though it has a 40mbit bit-rate, it's the closest I can get to true loss-less conversions without presets.

[MoDJ]

Best answer is here: stackoverflow.com/questions/6701805/h264-lossless-coding/…

[Hamed Tabatabaei]

I see what he adds is pixel_format:444. Although it will be theoretically more lossless to have it, but in 99.9% of cases the input itself is already chroma-subsampled to 4:2:0. So practically no advantage in that. All a person needs is "-qp 0".

[Валерий Заподовников]

Hamed, that is not tur for 10 bit, because only high444 supports lossless, high 10 is not lossless.