Converting by commandline produces poor quality

[bog_]

I'm trying to convert and AVI to h264 but the resulting mp4 file is painfully ugly. I'd like resulting file to match the video bitrate of the source, however, -sameq doesnt seem to work.

What am I doing wrong?


~/desktop Brian$ "/Applications/ffmpegX.app/Contents/Resources/ffmpeg" -i lo.avi -vcodec h264 -acodec aac -ab 128 -sameq lo.mp4

FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
Mac OSX universal build for ffmpegX
configuration: --enable-memalign-hack --enable-mp3lame --enable-gpl --disable-vhook --disable-ffplay --disable-ffserver --enable-a52 --enable-xvid --enable-faac --enable-faad --enable-amr_nb --enable-amr_wb --enable-pthreads --enable-x264
libavutil version: 49.0.0
libavcodec version: 51.9.0
libavformat version: 50.4.0
built on Apr 15 2006 04:58:19, gcc: 4.0.1 (Apple Computer, Inc. build 5250)
Input #0, avi, from 'lo.avi':
Duration: 00:41:32.5, start: 0.000000, bitrate: 1180 kb/s
Stream #0.0, 23.98 fps(r): Video: mpeg4, yuv420p, 624x352
Stream #0.1: Audio: mp3, 48000 Hz, stereo, 128 kb/s
File 'lo.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'lo.mp4':
Stream #0.0, 23.98 fps(c): Video: h264, yuv420p, 624x352, q=2-31, 200 kb/s
Stream #0.1: Audio: aac, 48000 Hz, stereo, 128 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
[h264 @ 0x54340c]no need for a SAR
[h264 @ 0x54340c]using cpu capabilities MMX MMXEXT SSE SSE2
Press [q] to stop encoding
frame= 2029 q=29.0 Lsize= 6848kB time=84.5 bitrate= 663.6kbits/s
video:5479kB audio:1320kB global headers:0kB muxing overhead 0.710814%
[h264 @ 0x54340c]slice I:170 Avg QP:26.20 size: 9253
[h264 @ 0x54340c]slice P:1859 Avg QP:28.28 size: 2172
[h264 @ 0x54340c]mb I I16..4: 53.6% 0.0% 46.4%
[h264 @ 0x54340c]mb P I16..4: 9.2% 0.0% 0.0% P16..4: 36.5% 0.0% 0.0% 0.0% 0.0% skip:54.3%
[h264 @ 0x54340c]final ratefactor: 34.07
[h264 @ 0x54340c]kb/s:530.5
~/desktop Brian$

[Case]

If "-sameq" does what I think it does (same quantizer value) then that won't work as regular MPEG-4 (DivX, XviD, etc.) and H.264 use different quantizer scales. The first goes 1-31, the latter 2 to 51 on a logarithmic scale.

Why not just set the target average bitrate to 617 kbps, per the GUI's advice for mentioned framerate and size? That should give a very decent output.