[FFmpeg-trac] #6570(avfilter:new): loudnorm filter changes sample rate
FFmpeg
trac at avcodec.org
Sun Aug 6 22:15:29 EEST 2017
#6570: loudnorm filter changes sample rate
----------------------------------+--------------------------------------
Reporter: slhck | Type: defect
Status: new | Priority: normal
Component: avfilter | Version: git-master
Keywords: loudnorm | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
----------------------------------+--------------------------------------
The `loudnorm` filter changes the sample rate of the input output stream,
sometimes doubling it, sometimes it will be even higher.
The desired behavior would be that the sample rate remains the same.
{{{
./ffmpeg -f lavfi -i anullsrc=r=48000 -filter:a loudnorm -t 1 out.wav
ffmpeg version N-86910-g797c232-tessus Copyright (c) 2000-2017 the FFmpeg
developers
built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-
version=tessus --enable-avisynth --enable-fontconfig --enable-gpl
--enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm
--enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-libopus --enable-libsnappy --enable-
libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-
libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack
--enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid
--enable-libzmq --enable-libzvbi --enable-version3 --disable-ffplay
--disable-indev=qtkit
libavutil 55. 69.100 / 55. 69.100
libavcodec 57.102.100 / 57.102.100
libavformat 57. 76.100 / 57. 76.100
libavdevice 57. 7.100 / 57. 7.100
libavfilter 6. 95.100 / 6. 95.100
libswscale 4. 7.101 / 4. 7.101
libswresample 2. 8.100 / 2. 8.100
libpostproc 54. 6.100 / 54. 6.100
Input #0, lavfi, from 'anullsrc=r=48000':
Duration: N/A, start: 0.000000, bitrate: 768 kb/s
Stream #0:0: Audio: pcm_u8, 48000 Hz, stereo, u8, 768 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (pcm_u8 (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, wav, to 'out.wav':
Metadata:
ISFT : Lavf57.76.100
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 192000 Hz,
stereo, s16, 6144 kb/s
Metadata:
encoder : Lavc57.102.100 pcm_s16le
size= 750kB time=00:00:01.00 bitrate=6144.8kbits/s speed=6.65x
video:0kB audio:750kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.013281%
}}}
{{{
./ffmpeg -f lavfi -i anullsrc=r=44100 -filter:a loudnorm -t 1 -c:a aac
out.m4a
ffmpeg version N-86910-g797c232-tessus Copyright (c) 2000-2017 the FFmpeg
developers
built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-
version=tessus --enable-avisynth --enable-fontconfig --enable-gpl
--enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm
--enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-libopus --enable-libsnappy --enable-
libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-
libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack
--enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid
--enable-libzmq --enable-libzvbi --enable-version3 --disable-ffplay
--disable-indev=qtkit
libavutil 55. 69.100 / 55. 69.100
libavcodec 57.102.100 / 57.102.100
libavformat 57. 76.100 / 57. 76.100
libavdevice 57. 7.100 / 57. 7.100
libavfilter 6. 95.100 / 6. 95.100
libswscale 4. 7.101 / 4. 7.101
libswresample 2. 8.100 / 2. 8.100
libpostproc 54. 6.100 / 54. 6.100
Input #0, lavfi, from 'anullsrc=r=44100':
Duration: N/A, start: 0.000000, bitrate: 705 kb/s
Stream #0:0: Audio: pcm_u8, 44100 Hz, stereo, u8, 705 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (pcm_u8 (native) -> aac (native))
Press [q] to stop, [?] for help
Output #0, ipod, to 'out.m4a':
Metadata:
encoder : Lavf57.76.100
Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 96000 Hz, stereo,
fltp, 128 kb/s
Metadata:
encoder : Lavc57.102.100 aac
size= 2kB time=00:00:01.00 bitrate= 13.7kbits/s speed=6.96x
video:0kB audio:1kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 192.006805%
[aac @ 0x7f8452003600] Qavg: 65030.441
}}}
This has also been observed by a user here:
https://superuser.com/questions/1218471/
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6570>
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