[FFmpeg-trac] #431(undetermined:open): When converting audio to an MP3 using CBR, result is reported VBR
FFmpeg
trac at avcodec.org
Tue Nov 15 21:04:24 CET 2011
#431: When converting audio to an MP3 using CBR, result is reported VBR
-------------------------------------+-------------------------------------
Reporter: schtorch | Owner: michael
Type: defect | Status: open
Priority: normal | Component:
Version: git-master | undetermined
Keywords: CBR mp3 | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
-------------------------------------+-------------------------------------
Comment (by schtorch):
This is fixed indeed!
Test CBR:
{{{
$ ffmpeg -i test.mp4 -ab 128k test.mp3
ffmpeg version N-34877-g53cb0de, Copyright (c) 2000-2011 the FFmpeg
developers
built on Nov 15 2011 16:26:55 with gcc 4.5.1 20101208 [gcc-4_5-branch
revision 167585]
configuration: --enable-gpl --enable-version3 --enable-shared --enable-
nonfree --enable-postproc --enable-libfaac --enable-libmp3lame --enable-
libopencore-amrnb --enable-libopencore-amrwb --enable-libvorbis --enable-
libtheora --enable-libvpx --enable-libspeex --enable-libxvid --enable-
libx264 --disable-network --disable-stripping --enable-libschroedinger
--enable-libdirac --enable-libgsm --enable-avfilter --enable-pthreads
--disable-doc --disable-ffplay --disable-ffserver --extra-
cflags=-I/usr/local/include --extra-ldflags=-L/usr/local/lib
libavutil 51. 25. 0 / 51. 25. 0
libavcodec 53. 34. 0 / 53. 34. 0
libavformat 53. 20. 0 / 53. 20. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 48. 1 / 2. 48. 1
libswscale 2. 1. 0 / 2. 1. 0
libpostproc 51. 2. 0 / 51. 2. 0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.87.1
Duration: 00:00:55.28, start: 0.000000, bitrate: 618 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
400x222, 485 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
s16, 127 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name :
File 'test.mp3' already exists. Overwrite ? [y/N] y
Output #0, mp3, to 'test.mp3':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
TDEN : 1970-01-01 00:00:00
TSSE : Lavf53.20.0
Stream #0:0(und): Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name :
Stream mapping:
Stream #0:1 -> #0:0 (aac -> libmp3lame)
Press [q] to stop, [?] for help
size= 864kB time=00:00:55.24 bitrate= 128.1kbits/s
video:0kB audio:863kB global headers:0kB muxing overhead 0.066065%
}}}
Result CBR:
{{{
mediainfo test.mp3
General
Complete name : test.mp3
Format : MPEG Audio
File size : 864 KiB
Duration : 55s 275ms
Overall bit rate : 128 Kbps
Encoded date : UTC 1970-01- 1 00:00:00
Writing library : LAME3.99
Encoding settings : Lavf53.20.0
major_brand : isom
minor_version : 512
compatible_brands : isomiso2avc1mp41
Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Mode : Joint stereo
Mode extension : MS Stereo
Duration : 55s 275ms
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 2 channels
Sampling rate : 44.1 KHz
Stream size : 864 KiB (100%)
Writing library : LAME3.99
}}}
Test VBR:
{{{
$ ffmpeg -i test.mp4 -qscale 1 test.mp3
ffmpeg version N-34877-g53cb0de, Copyright (c) 2000-2011 the FFmpeg
developers
built on Nov 15 2011 16:26:55 with gcc 4.5.1 20101208 [gcc-4_5-branch
revision 167585]
configuration: --enable-gpl --enable-version3 --enable-shared --enable-
nonfree --enable-postproc --enable-libfaac --enable-libmp3lame --enable-
libopencore-amrnb --enable-libopencore-amrwb --enable-libvorbis --enable-
libtheora --enable-libvpx --enable-libspeex --enable-libxvid --enable-
libx264 --disable-network --disable-stripping --enable-libschroedinger
--enable-libdirac --enable-libgsm --enable-avfilter --enable-pthreads
--disable-doc --disable-ffplay --disable-ffserver --extra-
cflags=-I/usr/local/include --extra-ldflags=-L/usr/local/lib
libavutil 51. 25. 0 / 51. 25. 0
libavcodec 53. 34. 0 / 53. 34. 0
libavformat 53. 20. 0 / 53. 20. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 48. 1 / 2. 48. 1
libswscale 2. 1. 0 / 2. 1. 0
libpostproc 51. 2. 0 / 51. 2. 0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 1970-01-01 00:00:00
encoder : Lavf52.87.1
Duration: 00:00:55.28, start: 0.000000, bitrate: 618 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
400x222, 485 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo,
s16, 127 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name :
File 'test.mp3' already exists. Overwrite ? [y/N] y
Output #0, mp3, to 'test.mp3':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
TDEN : 1970-01-01 00:00:00
TSSE : Lavf53.20.0
Stream #0:0(und): Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s
Metadata:
creation_time : 1970-01-01 00:00:00
handler_name :
Stream mapping:
Stream #0:1 -> #0:0 (aac -> libmp3lame)
Press [q] to stop, [?] for help
size= 1849kB time=00:00:55.24 bitrate= 274.2kbits/s
video:0kB audio:1849kB global headers:0kB muxing overhead 0.030847%
}}}
Result VBR:
{{{
mediainfo test.mp3
General
Complete name : test.mp3
Format : MPEG Audio
File size : 1.81 MiB
Encoded date : UTC 1970-01- 1 00:00:00
Writing library : LAME3.99
Encoding settings : Lavf53.20.0
major_brand : isom
minor_version : 512
compatible_brands : isomiso2avc1mp41
Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Mode : Joint stereo
Mode extension : MS Stereo
Bit rate mode : Variable
Channel(s) : 2 channels
Sampling rate : 44.1 KHz
Stream size : 1.81 MiB (100%)
Writing library : LAME3.99
}}}
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/431#comment:16>
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