[FFmpeg-user] Convert RAW AVI file to lossless ffvhuff and produce JPG images

[Robert Krüger]

On Thu, Aug 8, 2013 at 6:44 PM, James Board <jpboard2 at yahoo.com> wrote:
>>ah, sorry. responded to the other thread before reading this. Did you
>>try adding "-q:v 1 " to your command line to set the jpg quality?
>
> No, haven't tried it yet.  Will do.  Thanks (assuming it works).
>
> BTW, how do you know these things?  I'd like to answer these
> questions on my own, but -q:v isn't in the the ffmpeg documentation
> anywhere.  And the image2 muxer section doesn't mention how to
> set the JPEG image quality anywhere.

it actually is but admittedly a bit hidden in 5.4 "Main Options"

‘-q[:stream_specifier] q
(output,per-stream)’‘-qscale[:stream_specifier] q (output,per-stream)’

Use fixed quality scale (VBR). The meaning of q is codec-dependent.

This is something that would probably be best documented for new users
in a kind of how-to document because it is one of the more important
ones to know but as always, someone must volunteer to write and
maintain such a document. But I would guess that it is in one of the
documents that you find when googling around. Problem with those is
that many of them are outdated or plain wrong :-(. ffmpeg is such a
powerful and fast-evolving tool that writing and maintaining
comprehensive docs is a lot of work but documentation has improved _a
lot_ in the past 2 years.