[MEncoder-users] avi to h264 crashing itunes
sebastian_ml at gmx.net
Fri Sep 12 19:18:18 CEST 2008
Am Freitag, den 12.09.2008, 11:52 -0400 schrieb Christian Ebert:
> * Guillaume POIRIER on Friday, September 12, 2008 at 17:25:32 +0200
> > On Tue, Sep 9, 2008 at 7:26 PM, Sebastian Kemper <sebastian_ml at gmx.net> wrote:
> >> Am Montag, den 08.09.2008, 20:44 -0500 schrieb Philip Brodd:
> >>> $ mencoder input.avi \
> >>> -of lavf -lavfopts format=mp4 -vf dsize=560:-2,harddup \
> >>> -ovc x264 -x264encopts bitrate=800:me=hex:pass=2:turbo=1 \
> >>> -oac faac -faacopts mpeg=4:object=2:br=96 -channels 2 -srate 48000 \
> >>> -o output2.mp4
> >> Hi Philip,
> >> "nocabac:level_idc=30" is needed ("B" frames are disabled per default).
> >> Btw "trellis" needs CABAC from what I read so you can just let it go.
> > I'm pretty confident that this isn't correct.
> Well, from my experiences with ffmpeg nocabac *is* needed;
> level_idc can be either 30 (I use it for vga size 640:480) or 13
> (my preference for qvga 320:240).
> However I believe that trellis works.
And I quote:
1: enabled only on the final encode of a MB
2: enabled on all mode decisions
The main decision made in quantization is which coefficients to round up
and which to round down. Trellis chooses the optimal rounding choices
for the maximum rate-distortion score, to maximize PSNR relative to
bitrate. This generally increases quality relative to bitrate by about
5% for a somewhat small speed cost. It should generally be enabled. Note
that trellis requires CABAC."
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