[FFmpeg-trac] #2484(avfilter:closed): atempo - low accuracy

FFmpeg trac at avcodec.org
Thu Apr 25 15:50:15 CEST 2013


#2484: atempo - low accuracy
------------------------------------+-------------------------------------
             Reporter:  bars        |                    Owner:  pkoshevoy
                 Type:  defect      |                   Status:  closed
             Priority:  normal      |                Component:  avfilter
              Version:  git-master  |               Resolution:  fixed
             Keywords:  atempo      |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |
------------------------------------+-------------------------------------

Comment (by bars):

 Replying to [comment:8 cehoyos]:
 > Fixed
 Not yet fully

 For a test file from the first post:
 been: 00:40:44.864 => 00:42:29.407 (407ms) (atempo=24000/25025)
 it is now: 00:40:44.864 => 00:42:29.2'''57''' (257ms) (atempo=24000/25025)

 When atempo=24000/25025(0.959040959041) correct length must be at
 00:42:29.2'''80''' ('''280ms'''!)

 My test file, link: http://www.sendspace.com/file/oa1org
 link(mirror): http://sendfile.su/801269

 {{{
 $ ffmpeg -i Real_Sound(=2444.864).wav -af "atempo=24000/25025"
 out_Real_Sound.wav

 ffmpeg version N-52458-gaa96439 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Apr 24 2013 22:24:12 with gcc 4.8.0 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
 --enable-gnutls --enable-iconv --enable-libass --enable-libbluray
 --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc
 --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-
 libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
 --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs
 --enable-libxvid --enable-zlib
   libavutil      52. 27.101 / 52. 27.101
   libavcodec     55.  6.100 / 55.  6.100
   libavformat    55.  3.100 / 55.  3.100
   libavdevice    55.  0.100 / 55.  0.100
   libavfilter     3. 60.101 /  3. 60.101
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 [wav @ 000000000031b5e0] max_analyze_duration 5000000 reached at 5034667
 microseconds
 Guessed Channel Layout for  Input Stream #0.0 : mono
 Input #0, wav, from 'Real_Sound(=2444.864).wav':
   Metadata:
     encoder         : Lavf55.3.100
   Duration: 00:40:44.86, bitrate: 768 kb/s
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono,
 s16, 768 kb/s
 Output #0, wav, to 'out_Real_Sound.wav':
   Metadata:
     ISFT            : Lavf55.3.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono,
 s16, 768 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le -> pcm_s16le)
 Press [q] to stop, [?] for help
 size=   14153kB time=00:02:30.96 bitrate= 768.0kbits/s
 size=   28214kB time=00:05:00.94 bitrate= 768.0kbits/s
 size=   42475kB time=00:07:33.06 bitrate= 768.0kbits/s
 size=   56673kB time=00:10:04.51 bitrate= 768.0kbits/s
 size=   70780kB time=00:12:34.98 bitrate= 768.0kbits/s
 size=   85096kB time=00:15:07.68 bitrate= 768.0kbits/s
 size=   99353kB time=00:17:39.76 bitrate= 768.0kbits/s
 size=  113576kB time=00:20:11.47 bitrate= 768.0kbits/s
 size=  127875kB time=00:22:43.99 bitrate= 768.0kbits/s
 size=  142136kB time=00:25:16.11 bitrate= 768.0kbits/s
 size=  156406kB time=00:27:48.32 bitrate= 768.0kbits/s
 size=  170708kB time=00:30:20.88 bitrate= 768.0kbits/s
 size=  184961kB time=00:32:52.91 bitrate= 768.0kbits/s
 size=  199143kB time=00:35:24.19 bitrate= 768.0kbits/s
 size=  213275kB time=00:37:54.93 bitrate= 768.0kbits/s
 size=  227332kB time=00:40:24.87 bitrate= 768.0kbits/s
 size=  238993kB time=00:42:29.25 bitrate= 768.0kbits/s

 video:0kB audio:238993kB subtitle:0 global headers:0kB muxing overhead
 0.000033%
 }}}

 To create a file with a duration 00:40:44.864 - tempo is working correct
 00:42:29.2'''79''' (nearly 280ms):
 {{{
 $ ffmpeg -f lavfi -i "aevalsrc=sin(2*PI*t*440):d=2444.864:s=48k"
 2444.864.wav

 ffmpeg version N-52458-gaa96439 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Apr 24 2013 22:24:12 with gcc 4.8.0 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
 --enable-gnutls --enable-iconv --enable-libass --enable-libbluray
 --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc
 --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-
 libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
 --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs
 --enable-libxvid --enable-zlib
   libavutil      52. 27.101 / 52. 27.101
   libavcodec     55.  6.100 / 55.  6.100
   libavformat    55.  3.100 / 55.  3.100
   libavdevice    55.  0.100 / 55.  0.100
   libavfilter     3. 60.101 /  3. 60.101
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, lavfi, from 'aevalsrc=sin(2*PI*t*440):d=2444.864:s=48k':
   Duration: N/A, start: 0.000000, bitrate: 3072 kb/s
     Stream #0:0: Audio: pcm_f64le, 48000 Hz, mono, dbl, 3072 kb/s
 Output #0, wav, to '2444.864.wav':
   Metadata:
     ISFT            : Lavf55.3.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono,
 s16, 768 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_f64le -> pcm_s16le)
 Press [q] to stop, [?] for help
 size=    7070kB time=00:01:15.41 bitrate= 768.0kbits/s
 size=   14170kB time=00:02:31.14 bitrate= 768.0kbits/s
 size=   21234kB time=00:03:46.49 bitrate= 768.0kbits/s
 size=   28354kB time=00:05:02.44 bitrate= 768.0kbits/s
 size=   35470kB time=00:06:18.34 bitrate= 768.0kbits/s
 size=   42594kB time=00:07:34.33 bitrate= 768.0kbits/s
 size=   49738kB time=00:08:50.53 bitrate= 768.0kbits/s
 size=   56842kB time=00:10:06.31 bitrate= 768.0kbits/s
 size=   63962kB time=00:11:22.26 bitrate= 768.0kbits/s
 size=   71002kB time=00:12:37.35 bitrate= 768.0kbits/s
 size=   78112kB time=00:13:53.19 bitrate= 768.0kbits/s
 size=   85176kB time=00:15:08.54 bitrate= 768.0kbits/s
 size=   92306kB time=00:16:24.59 bitrate= 768.0kbits/s
 size=   99430kB time=00:17:40.58 bitrate= 768.0kbits/s
 size=  106554kB time=00:18:56.57 bitrate= 768.0kbits/s
 size=  113678kB time=00:20:12.56 bitrate= 768.0kbits/s
 size=  120794kB time=00:21:28.46 bitrate= 768.0kbits/s
 size=  127910kB time=00:22:44.37 bitrate= 768.0kbits/s
 size=  135030kB time=00:24:00.32 bitrate= 768.0kbits/s
 size=  142092kB time=00:25:15.64 bitrate= 768.0kbits/s
 size=  149204kB time=00:26:31.50 bitrate= 768.0kbits/s
 size=  156338kB time=00:27:47.60 bitrate= 768.0kbits/s
 size=  163466kB time=00:29:03.63 bitrate= 768.0kbits/s
 size=  170552kB time=00:30:19.22 bitrate= 768.0kbits/s
 size=  177674kB time=00:31:35.18 bitrate= 768.0kbits/s
 size=  184804kB time=00:32:51.24 bitrate= 768.0kbits/s
 size=  191918kB time=00:34:07.12 bitrate= 768.0kbits/s
 size=  199032kB time=00:35:23.00 bitrate= 768.0kbits/s
 size=  206140kB time=00:36:38.82 bitrate= 768.0kbits/s
 size=  213266kB time=00:37:54.83 bitrate= 768.0kbits/s
 size=  220322kB time=00:39:10.10 bitrate= 768.0kbits/s
 size=  227446kB time=00:40:26.09 bitrate= 768.0kbits/s
 size=  229206kB time=00:40:44.86 bitrate= 768.0kbits/s

 video:0kB audio:229206kB subtitle:0 global headers:0kB muxing overhead
 0.000034%
 }}}

 {{{
 $ ffmpeg -i 2444.864.wav -af "atempo=24000/25025" out.wav

 ffmpeg version N-52458-gaa96439 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Apr 24 2013 22:24:12 with gcc 4.8.0 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
 --enable-gnutls --enable-iconv --enable-libass --enable-libbluray
 --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc
 --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-
 libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
 --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs
 --enable-libxvid --enable-zlib
   libavutil      52. 27.101 / 52. 27.101
   libavcodec     55.  6.100 / 55.  6.100
   libavformat    55.  3.100 / 55.  3.100
   libavdevice    55.  0.100 / 55.  0.100
   libavfilter     3. 60.101 /  3. 60.101
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  3.100 / 52.  3.100
 [wav @ 00000000002cd6c0] max_analyze_duration 5000000 reached at 5034667
 microseconds
 Guessed Channel Layout for  Input Stream #0.0 : mono
 Input #0, wav, from '2444.864.wav':
   Metadata:
     encoder         : Lavf55.3.100
   Duration: 00:40:44.86, bitrate: 768 kb/s
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono,
 s16, 768 kb/s
 Output #0, wav, to 'out.wav':
   Metadata:
     ISFT            : Lavf55.3.100
     Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, mono,
 s16, 768 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le -> pcm_s16le)
 Press [q] to stop, [?] for help
 size=   14186kB time=00:02:31.31 bitrate= 768.0kbits/s
 size=   28426kB time=00:05:03.21 bitrate= 768.0kbits/s
 size=   42583kB time=00:07:34.22 bitrate= 768.0kbits/s
 size=   56824kB time=00:10:06.11 bitrate= 768.0kbits/s
 size=   71060kB time=00:12:37.96 bitrate= 768.0kbits/s
 size=   85321kB time=00:15:10.08 bitrate= 768.0kbits/s
 size=   99582kB time=00:17:42.20 bitrate= 768.0kbits/s
 size=  113831kB time=00:20:14.19 bitrate= 768.0kbits/s
 size=  128083kB time=00:22:46.22 bitrate= 768.0kbits/s
 size=  142311kB time=00:25:17.98 bitrate= 768.0kbits/s
 size=  156481kB time=00:27:49.12 bitrate= 768.0kbits/s
 size=  170650kB time=00:30:20.26 bitrate= 768.0kbits/s
 size=  184844kB time=00:32:51.67 bitrate= 768.0kbits/s
 size=  199072kB time=00:35:23.43 bitrate= 768.0kbits/s
 size=  213271kB time=00:37:54.88 bitrate= 768.0kbits/s
 size=  227473kB time=00:40:26.38 bitrate= 768.0kbits/s
 size=  238995kB time=00:42:29.27 bitrate= 768.0kbits/s

 video:0kB audio:238995kB subtitle:0 global headers:0kB muxing overhead
 0.000033%
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2484#comment:9>
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