[Ffmpeg-devel] Capturing every keyframe from a DVD

[Michael Niedermayer]

Hi

On Monday 13 June 2005 21:21, Rich Felker wrote:
> On Mon, Jun 13, 2005 at 04:50:06PM +0200, M?ns Rullg?rd wrote:
> > Clayton Brown <clayton.brown at digitalrum.com> writes:
> > > Does anyone know how to save every keyframe from a DVD into a format
> > > such as JPG/TIFF etc.
> >
> > Extract the video stream, and send it through an AVParser.  Discard
> > any non-I frames, and decode the I frames using libavcodec as usual.
> > Save the decoded frames to separate images using your favorite library
> > for your format of choice (libavcodec/libavformat handles some of
> > them).
>
> Actually there should be a way to convert mpeg1(/2/4?) keyframes into
> jpeg files losslessly without decoding and reencoding, shouldn't
> there? :)

no, not really, unless you use lossless jpeg or accept the differences from 
different quantization & colorspace

[...]
-- 
Michael