Re: normalize-audio and video files

[Emanuel Berg <embe8573@student.uu.se>]

Nicolas George <george@nsup.org> writes:

> At both steps, you are transcoding. That means you
> are paying the MP3 toll twice, including CPU time
> and quality loss.
>
> I do not know how normalize-audio operates. It is
> theoretically possible to adjust the volume without
> transcoding, but I suppose this is tricky, and I do
> not know if normalize-audio implements it.
>
> If normalize-audio can do it, then using "-c copy"
> to avoid transcoding is the correct solution. If it
> can not, then use a raw PCM format as intermediate
> format; the obvious choice is WAVE.
>
> Also, you say that normalize-audio is lightning
> fast, this is bad sign, because computing the volume
> of a clip accurately is expensive.

normalize-audio is fast with audio files - it doesn't
work *at all* with movies. If normalized-audio worked
with mp4 movies, I would already have my tool.

You mean, I should use `-c copy' for both
ffmpeg calls?

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