Opened 12 years ago
Closed 11 years ago
#1346 closed defect (fixed)
-aq makes only a minimal output file size difference for aac
Reported by: | Carl Eugen Hoyos | Owned by: | |
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Priority: | normal | Component: | avcodec |
Version: | git-master | Keywords: | aac |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
The native aac encoder source code contains hints that global_quality is respected, but setting -aq makes only a minimal output file size difference.
This used to work before release 0.6.
$ ffmpeg -i fate-suite/lossless-audio/luckynight-partial.tta -strict experimental -q:a 0.001 -t 8 out.aac ffmpeg version N-40960-ge15f128 Copyright (c) 2000-2012 the FFmpeg developers built on May 23 2012 13:44:40 with gcc 4.3.2 configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl --enable-libopenjpeg --enable-libvorbis --enable-libspeex --enable-libmp3lame --enable-libtheora --extra-ldflags=-lm libavutil 51. 53.100 / 51. 53.100 libavcodec 54. 23.100 / 54. 23.100 libavformat 54. 6.100 / 54. 6.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 76.100 / 2. 76.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 Input #0, tta, from 'fate-suite/lossless-audio/luckynight-partial.tta': Duration: 00:01:00.48, start: 0.000000, bitrate: 138 kb/s Stream #0:0: Audio: tta, 44100 Hz, stereo, s16 [aformat @ 0x8f14200] auto-inserting filter 'auto-inserted resampler 0' between the filter 'src' and the filter 'aformat' [aresample @ 0x8f0b920] r:44100Hz -> r:44100Hz Output #0, adts, to 'out.aac': Metadata: encoder : Lavf54.6.100 Stream #0:0: Audio: aac, 44100 Hz, stereo, flt, 128 kb/s Stream mapping: Stream #0:0 -> #0:0 (tta -> aac) Press [q] to stop, [?] for help size= 137kB time=00:00:08.35 bitrate= 134.6kbits/s video:0kB audio:135kB global headers:0kB muxing overhead 1.826173%
$ ffmpeg -i fate-suite/lossless-audio/luckynight-partial.tta -strict experimental -q:a 100000 -t 8 out.aac ffmpeg version N-40960-ge15f128 Copyright (c) 2000-2012 the FFmpeg developers built on May 23 2012 13:44:40 with gcc 4.3.2 configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl --enable-libopenjpeg --enable-libvorbis --enable-libspeex --enable-libmp3lame --enable-libtheora --extra-ldflags=-lm libavutil 51. 53.100 / 51. 53.100 libavcodec 54. 23.100 / 54. 23.100 libavformat 54. 6.100 / 54. 6.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 76.100 / 2. 76.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 Input #0, tta, from 'fate-suite/lossless-audio/luckynight-partial.tta': Duration: 00:01:00.48, start: 0.000000, bitrate: 138 kb/s Stream #0:0: Audio: tta, 44100 Hz, stereo, s16 [aformat @ 0x8f14200] auto-inserting filter 'auto-inserted resampler 0' between the filter 'src' and the filter 'aformat' [aresample @ 0x8f0b920] r:44100Hz -> r:44100Hz Output #0, adts, to 'out.aac': Metadata: encoder : Lavf54.6.100 Stream #0:0: Audio: aac, 44100 Hz, stereo, flt, 128 kb/s Stream mapping: Stream #0:0 -> #0:0 (tta -> aac) Press [q] to stop, [?] for help size= 144kB time=00:00:08.35 bitrate= 140.9kbits/s video:0kB audio:141kB global headers:0kB muxing overhead 1.742700%
Change History (3)
comment:1 by , 12 years ago
Summary: | q:a for -acodec aac → -aq makes only a minimal output file size difference for aac |
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comment:2 by , 11 years ago
comment:3 by , 11 years ago
Resolution: | → fixed |
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Status: | new → closed |
Considering this fixed as varying -aq values now make significant differences in output file size and quality, but I did not attempt to find responsible commits.
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The behavior has changed, but I am unsure of which commits are responsible:
Ticket #2686 may introduce more changes.