[FFmpeg-user] Convert RAW AVI file to lossless ffvhuff and produce JPG images
krueger at lesspain.de
Thu Aug 8 20:40:01 CEST 2013
On Thu, Aug 8, 2013 at 8:08 PM, James Board <jpboard2 at yahoo.com> wrote:
>>it actually is but admittedly a bit hidden in 5.4 "Main Options"
>>(output,per-stream)’‘-qscale[:stream_specifier] q (output,per-stream)’
>>Use fixed quality scale (VBR). The meaning of q is codec-dependent.
> I'm looking at the "documentation" right now and still don't see how
> the "documentation" even remotely implies "-q:v 1" sets the quality
> of the jpeg image generation. As far as I can tell, there's only '-q 1'
> in the "documentation", and it merely selects a stream for whatever reason.
the stream specifier selects which stream the option applies to (e.g.
q:v sets the video stream and q:a the audio stream quality). It's a
general concept (see
http://ffmpeg.org/ffmpeg.html#Stream-specifiers-1) and yes, nobody
blames you for not finding the information you were looking for in
that piece of text ;-). "Use fixed quality scale (VBR). The meaning of
q is codec-dependent." does not tell you that in the case of the mjpeg
codec (which is used for writing JPEG images) 1 is the highest
quality. It's simply suboptimal/incomplete. It's done by volunteers in
their spare time and help in improving the docs is definitely greatly
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