Here's the description I'll add to the mplayer man page:
---
Causes frames with higher quantizers to be more likely to trigger a
scene change detection and make libavcodec use an I-frame (default: 1).
1-16 is a sane range.
Values between 2 and 6 may yield increasing PSNR (up to approximately
0.04 dB) and better placement of I-frames in high-motion scenes.
Higher values than 6 may give very slightly better PSNR (approximately
0.01 dB more than sc_factor=6), but noticably worse visual quality.
---
Original idea from Michael; patch by me.
Originally committed as revision 4883 to svn://svn.ffmpeg.org/ffmpeg/trunk
anyway, this change decreases bitrate and increase PSNR by ~1.00 on my test file, other files also benefit significantly
Originally committed as revision 4771 to svn://svn.ffmpeg.org/ffmpeg/trunk
different intra block coding (previous was just an ugly hack)
1.8% bitrate reduction -0.01PSNR (foreman@352x288 qscale=8)
1.5% bitrate reduction +0.05PSNR (foreman@352x288 qscale=1)
Originally committed as revision 3416 to svn://svn.ffmpeg.org/ffmpeg/trunk
wavelet based compare functions
make epzs_motion_search() more flexible so it can be used for a wider range of block sizes
make get_penalty_factor() independant of MpegEncContext
Originally committed as revision 3410 to svn://svn.ffmpeg.org/ffmpeg/trunk
be somewhat more tollerant on invalid input
return INT_MAX instead of -1 for unuseable mv/mb types as that ensures nicely that they arent used
initalize limits earlier for b frames
a few more asserts to check for out of picture vectors
Originally committed as revision 3213 to svn://svn.ffmpeg.org/ffmpeg/trunk
finetune bit/distortion weighting factor used in motion estimation, the old coeffs where finetuned relative to incorrect mv_penalty tables which where then fixed later but the coeffs where not
this _may_ fix the long standing blocking artifacts, but may also introduce mudding artefacts theoretically, so please tell us if u stumble across any so we can either fix them or export this variable so the user can change it
Originally committed as revision 3189 to svn://svn.ffmpeg.org/ffmpeg/trunk
currently works only with mpeg1/2 source or some luck
may need -sync 0 as otherwise framedrops could lead to extreemly long b frame sequences
Originally committed as revision 3042 to svn://svn.ffmpeg.org/ffmpeg/trunk
replace ugly macros by always_inline functions, that way its much more readable and flexible as always_inline can simply be removed while the macros couldnt be
about 0.5 % speedup with default parameters
Originally committed as revision 3037 to svn://svn.ffmpeg.org/ffmpeg/trunk
multithreaded/SMP encoding for MPEG1/MPEG2/MPEG4/H263
all pthread specific code is in pthread.c
to try it, run configure --enable-pthreads and ffmpeg ... -threads <num>
the internal thread API is a simple AVCodecContext.execute() callback which executes a given function pointer with different arguments and returns after finishing all, that way no mutexes or other thread-mess is needed outside pthread.c
Originally committed as revision 2772 to svn://svn.ffmpeg.org/ffmpeg/trunk
bug was introduced in version 1.75 (2003-12-30)
this may have lead to a small drop in quality of the 4mv mode, but should have only affected the mbd=0 case
Originally committed as revision 2698 to svn://svn.ffmpeg.org/ffmpeg/trunk
function moved to dspcontext
mmx&mmx2 optimized
change SSE -> SAD as default (better quality)
vbv buffer size command line option in kbyte
Originally committed as revision 2669 to svn://svn.ffmpeg.org/ffmpeg/trunk
interlaced mpeg2 encoding
P & B frames
rate distored interlaced mb decission
alternate scantable support
4mv encoding fixes (thats also why the regression tests change)
passing height to most dsp functions
interlaced mpeg4 encoding (no direct mode MBs yet)
various related cleanups
disabled old motion estimaton algorithms (log, full, ...) they will either be fixed or removed
Originally committed as revision 2638 to svn://svn.ffmpeg.org/ffmpeg/trunk
Steve L'Homme
Corey Hickey
Diego Biurrun
Loren Merritt
Michael Niedermayer
Måns Rullgård
Mike Melanson
Falk Hüffner
Wolfgang Hesseler