[Libav-user] Encoding with no compression with OpenH264

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Mar 8 21:36:11 CET 2016

Arthur Muller <muller at ...> writes:

> ffmpeg -framerate 10 -i image%02d.png -c:v h264 output.mp4
> ffmpeg version 3.0 Copyright (c) 2000-2016 the FFmpeg developers

Still not recommended.
All releases contain more bugs and less features than 
current FFmpeg git head, in a few days you can use 
newer libopenh264 with current FFmpeg which may (or may 
not) improve quality.

>     Stream #0:0: Video: png, rgb24(pc), 1536x856, 
> 10 fps, 10 tbr, 10 tbn, 10 tbc

Note that there is an unavoidable quality loss if you 
compress rgb input with (baseline) h264 which implies 
yuv420p. If quality is really relevant, use qtrle (or 
keep png which can also be put into mov).

>     Stream #0:0: Video: h264 (libopenh264) ([33][0][0][0] / 0x0021), 
> yuv420p, 1536x856, q=2-31, 200 kb/s,

If you want to keep this (known to be bad quality) 
encoder, you have to use a very high bitrate if you 
want the best possible quality.
Test with something like -b:v 20k

Carl Eugen

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