[FFmpeg-devel] [PATCH/RFC] set qscale_type for MPEG-4

Michael Niedermayer michaelni
Wed Feb 3 03:38:29 CET 2010

On Wed, Feb 03, 2010 at 01:16:02AM +0100, Michael Niedermayer wrote:
> On Tue, Feb 02, 2010 at 11:54:26PM +0100, Reimar D?ffinger wrote:
> > Hello,
> > I have no idea if this actually makes sense, but MPlayer's -vf fspp seems to
> > look a lot better with it for me - no idea if MPEG-4 qscale is more similar
> > to MPEG-2 or MPEG-1.
> mpeg4 has 2 quantizer types, one matches h263 one mpeg2 with a factor of 2
> difference in qscale
> mpeg1 and 2 depend on the used quant matrixes as well, thus make tripple sure
> your test files use the default matrixes and mpeg4 uses h263 style
> or you will have to analyze the matrixes to
> adjust qscale. Also the reference is spp not fspp

an alternative to analyzing the matrixes would be to change spp so it uses
them in the quantization


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
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