[FFmpeg-trac] #48(FFmpeg:new): lowres quality degradation

[FFmpeg]

#48: lowres quality degradation
--------------------------+------------------------
  Reporter:  ami_stuff    |      Owner:  michael
      Type:  defect       |     Status:  new
  Priority:  normal       |  Component:  FFmpeg
   Version:  unspecified  |   Keywords:  regression
Blocked By:               |   Blocking:
Reproduced:  0            |   Analyzed:  0
--------------------------+------------------------
 Lowres option generates worse quality output than in the past. This is
 most likely x86-related bug (regression), beause I'm unable to reproduce
 the problem under m68k emulation.

 svn-r26325 - ok
 svn-r26359 - bad

 I uploaded the file to "incoming".

 ffplay -lowres 1 lowres_bug.avi

 --------

 C:\>ffmpeg -i C:\lowres_bug.avi
 FFmpeg version git-N-28799-gf354396, Copyright (c) 2000-2011 the FFmpeg
 develope
 rs
   built on Apr  2 2011 21:57:21 with gcc 4.5.2
   configuration: --enable-gpl --enable-version3 --enable-memalign-hack
 --arch=i6
 86 --target-os=mingw32 --cross-prefix=i686-w64-mingw32- --enable-avisynth
 --enab
 le-bzlib --enable-frei0r --enable-libopencore-amrnb --enable-libopencore-
 amrwb -
 -enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-
 libopenjpeg --e
 nable-librtmp --enable-libschroedinger --enable-libspeex --enable-
 libtheora --en
 able-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-
 libxvi
 d --enable-zlib --extra-cflags=-I/home/kyle/software/ffmpeg/external-
 libs/32-bit
 /include --extra-ldflags=-L/home/kyle/software/ffmpeg/external-
 libs/32-bit/lib -
 -pkg-config=pkg-config
   libavutil    50. 40. 0 / 50. 40. 0
   libavcodec   52.117. 0 / 52.117. 0
   libavformat  52.104. 0 / 52.104. 0
   libavdevice  52.  4. 0 / 52.  4. 0
   libavfilter   1. 76. 0 /  1. 76. 0
   libswscale    0. 13. 0 /  0. 13. 0
 [mp3 @ 02368F70] Header missing
 [mpeg4 @ 02360470] Invalid and inefficient vfw-avi packed B frames
 detected
 Input #0, avi, from 'C:\lowres_bug.avi':
   Duration: 00:00:12.64, start: 0.000000, bitrate: 395 kb/s
     Stream #0.0: Video: mpeg4, yuv420p, 320x240 [PAR 1:1 DAR 4:3], 23.97
 tbr, 23
 .97 tbn, 23.97 tbc
     Stream #0.1: Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s
 At least one output file must be specified

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/48>
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