[FFmpeg-devel] CNG (consistent noise generation) idea

Jonathan Campbell jonathan at impactstudiopro.com
Tue Aug 30 22:12:39 EEST 2016

I have some spare time again, I'd like to reimplement the "consistent 
noise generation" patch I made awhile back.

To clarify what that is, some codecs use pseudo-random noise generation 
in the decoding process (noise bands). The idea is to enable seeding 
that pseudo-random generator with the bytes of the audio frame so that 
the decoded output is always the same given the same compressed audio 
data. I'm not concerned with noise generation given silent audio blocks 
since silent audio blocks have no sound anyway. Software that needs 
consistent decoding (like NLE editing software) can enable this option.

Last time my patch was rejected because it used the flags field of the 
AVContext. I understand that the FFMPEG project would rather have it an 
option given through the av options dictionary instead, correct? I'm 
thinking the avoption should be named "cng" as a boolean set to 0 or 1, 
off by default.

Any suggestions?

Jonathan Campbell

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