Opened 13 years ago

Closed 13 years ago

#48 closed defect (fixed)

lowres quality degradation

Reported by: ami_stuff Owned by: Michael Niedermayer
Priority: normal Component: ffmpeg
Version: unspecified Keywords: regression
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

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

Change History (2)

comment:1 by ami_stuff, 13 years ago

This bug seems to be fixed (tested with git-N-29131-gf4bc923).

comment:2 by Carl Eugen Hoyos, 13 years ago

Resolution: fixed
Status: newclosed
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