Opened 7 years ago
Closed 7 years ago
#6607 closed defect (invalid)
ffplay has difficulty decoding 4.0 PCM
Reported by: | kieranjol | Owned by: | |
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Priority: | normal | Component: | ffplay |
Version: | git-master | Keywords: | |
Cc: | Marton Balint | Blocked By: | |
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug:
ffplay and VLC have issues playing 4.0 PCM audio, whether in WAV, MOV or MKV containers. When making sine
waves with lavfi
, ffplay produces silence for 4.0, though 2, 5, 6 channel audio is played back OK. VLC produces throbbing, distoreted audio but that's outside of the scope of this issue I guess.
How to reproduce:
Generate a sine wave with ffmpeg and then play it back with ffplay.
./ffmpeg -f lavfi -i "sine=frequency=1000:duration=5:sample_rate=48000" -ac 4 -c:a pcm_s24le test.wav ffmpeg version N-87034-geca2a49 Copyright (c) 2000-2017 the FFmpeg developers built with Apple LLVM version 7.3.0 (clang-703.0.31) configuration: libavutil 55. 74.100 / 55. 74.100 libavcodec 57.103.100 / 57.103.100 libavformat 57. 76.100 / 57. 76.100 libavdevice 57. 7.101 / 57. 7.101 libavfilter 6.100.100 / 6.100.100 libswscale 4. 7.102 / 4. 7.102 libswresample 2. 8.100 / 2. 8.100 Input #0, lavfi, from 'sine=frequency=1000:duration=5:sample_rate=48000': Duration: N/A, start: 0.000000, bitrate: 768 kb/s Stream #0:0: Audio: pcm_s16le, 48000 Hz, mono, s16, 768 kb/s File 'test.wav' already exists. Overwrite ? [y/N] y Stream mapping: Stream #0:0 -> #0:0 (pcm_s16le (native) -> pcm_s24le (native)) Press [q] to stop, [?] for help Output #0, wav, to 'test.wav': Metadata: ISFT : Lavf57.76.100 Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 4.0, s32, 4608 kb/s Metadata: encoder : Lavc57.103.100 pcm_s24le size= 2813kB time=00:00:05.00 bitrate=4608.2kbits/s speed= 432x video:0kB audio:2812kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.003542% ./ffplay test.wav ffplay version N-87034-geca2a49 Copyright (c) 2003-2017 the FFmpeg developers built with Apple LLVM version 7.3.0 (clang-703.0.31) configuration: libavutil 55. 74.100 / 55. 74.100 libavcodec 57.103.100 / 57.103.100 libavformat 57. 76.100 / 57. 76.100 libavdevice 57. 7.101 / 57. 7.101 libavfilter 6.100.100 / 6.100.100 libswscale 4. 7.102 / 4. 7.102 libswresample 2. 8.100 / 2. 8.100 Input #0, wav, from 'test.wav': Metadata: encoder : Lavf57.76.100 Duration: 00:00:05.00, bitrate: 4608 kb/s Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 4.0, s32 (24 bit), 4608 kb/s 3.46 M-A: -0.000 fd= 0 aq= 577KB vq= 0KB sq= 0B f=0/0
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.
Change History (4)
comment:1 by , 7 years ago
Version: | unspecified → git-master |
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comment:2 by , 7 years ago
comment:3 by , 7 years ago
Cc: | added |
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comment:4 by , 7 years ago
Resolution: | → invalid |
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Status: | new → closed |
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Have you checked all channels of your 5.1 setup? Your are generating a mono sound, then create 4 channels from it, so only center will contain a sound in test.wav, therefore when played, center will contain the sine wave, not front left or front right.