[FFmpeg-trac] #10038(undetermined:new): Wrong duration / speed in audio recording made with ffmpeg -f avfoundation
FFmpeg
trac at avcodec.org
Tue Nov 15 14:25:23 EET 2022
#10038: Wrong duration / speed in audio recording made with ffmpeg -f avfoundation
-------------------------------------+-------------------------------------
Reporter: Raimondas | Owner: (none)
Type: defect | Status: new
Priority: normal | Component:
| undetermined
Version: unspecified | Resolution:
Keywords: | Blocked By:
avfoundation |
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Comment (by Raimondas):
Retested with current Git head build, same problem:
- recorded ~20 sec of audio with MacBook Pro Microphone sampling rate set
to 96k
- resulting wav file is ~10 sec long
There is a bitrate discrepancy.
ffmpeg output:
{{{
./ffmpeg -debug 1 -f avfoundation -i ":0" -acodec pcm_s24le 96-24.wav
(7:08 0)
ffmpeg version N-109088-g52f7adfbde Copyright (c) 2000-2022 the FFmpeg
developers
built with Apple clang version 13.0.0 (clang-1300.0.29.30)
configuration:
libavutil 57. 42.100 / 57. 42.100
libavcodec 59. 52.102 / 59. 52.102
libavformat 59. 34.101 / 59. 34.101
libavdevice 59. 8.101 / 59. 8.101
libavfilter 8. 50.100 / 8. 50.100
libswscale 6. 8.112 / 6. 8.112
libswresample 4. 9.100 / 4. 9.100
matched as AVOption 'debug' with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with argument
'avfoundation'.
Reading option '-i' ... matched as input url with argument ':0'.
Reading option '-acodec' ... matched as option 'acodec' (force audio codec
('copy' to copy stream)) with argument 'pcm_s24le'.
Reading option '96-24.wav' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Successfully parsed a group of options.
Parsing a group of options: input url :0.
Applying option f (force format) with argument avfoundation.
Successfully parsed a group of options.
Opening an input file: :0.
[avfoundation @ 0x15ae05270] audio device 'MacBook Pro Microphone' opened
[avfoundation @ 0x15ae05270] All info found
Input #0, avfoundation, from ':0':
Duration: N/A, start: 337270.763406, bitrate: 3072 kb/s
Stream #0:0, 1, 1/1000000: Audio: pcm_f32le, 96000 Hz, mono, flt, 3072
kb/s
Successfully opened the file.
Parsing a group of options: output url 96-24.wav.
Applying option acodec (force audio codec ('copy' to copy stream)) with
argument pcm_s24le.
Successfully parsed a group of options.
Opening an output file: 96-24.wav.
[file @ 0x15ba06460] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
Stream mapping:
Stream #0:0 -> #0:0 (pcm_f32le (native) -> pcm_s24le (native))
Press [q] to stop, [?] for help
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless
if it occurs once at the start per stream)
Last message repeated 2 times
[avfoundation @ 0x15ae05270] Thread message queue blocking; consider
raising the thread_queue_size option (current value: 1)
detected 10 logical cores
[graph_0_in_0_0 @ 0x15ae28440] Setting 'time_base' to value '1/96000'
[graph_0_in_0_0 @ 0x15ae28440] Setting 'sample_rate' to value '96000'
[graph_0_in_0_0 @ 0x15ae28440] Setting 'sample_fmt' to value 'flt'
[graph_0_in_0_0 @ 0x15ae28440] Setting 'channel_layout' to value 'mono'
[graph_0_in_0_0 @ 0x15ae28440] tb:1/96000 samplefmt:flt samplerate:96000
chlayout:mono
[format_out_0_0 @ 0x15ae1be20] Setting 'sample_fmts' to value 's32'
[auto_aresample_0 @ 0x15ae15b20] Setting 'output_sample_bits' to value
'24'
[format_out_0_0 @ 0x15ae1be20] auto-inserting filter 'auto_aresample_0'
between the filter 'Parsed_anull_0' and the filter 'format_out_0_0'
[AVFilterGraph @ 0x15ae142c0] query_formats: 4 queried, 6 merged, 3
already done, 0 delayed
[auto_aresample_0 @ 0x15ae15b20] [SWR @ 0x140018000] Using fltp internally
between filters
[auto_aresample_0 @ 0x15ae15b20] ch:1 chl:mono fmt:flt r:96000Hz -> ch:1
chl:mono fmt:s32 r:96000Hz
Output #0, wav, to '96-24.wav':
Metadata:
ISFT : Lavf59.34.101
Stream #0:0, 0, 1/96000: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 96000
Hz, mono, s32, 2304 kb/s
Metadata:
encoder : Lavc59.52.102 pcm_s24le
size= 2560kB time=00:00:20.75 bitrate=1010.6kbits/s speed= 1x
[q] command received. Exiting.
All streams finished for output file #0
Terminating muxer thread 0
[AVIOContext @ 0x15ba064e0] Statistics: 2678894 bytes written, 4 seeks, 13
writeouts
size= 2616kB time=00:00:20.81 bitrate=1029.8kbits/s speed=0.999x
video:0kB audio:2616kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.003808%
Input file #0 (:0):
Input stream #0:0 (audio): 1744 packets read (3571712 bytes); 1744
frames decoded (892928 samples);
Total: 1744 packets (3571712 bytes) demuxed
Output file #0 (96-24.wav):
Output stream #0:0 (audio): 1744 frames encoded (892928 samples); 1744
packets muxed (2678784 bytes);
Total: 1744 packets (2678784 bytes) muxed
1744 frames successfully decoded, 0 decoding errors
Terminating demuxer thread 0
}}}
ffprobe output
{{{
./ffprobe 96-24.wav
(7:09 0)
ffprobe version N-109088-g52f7adfbde Copyright (c) 2007-2022 the FFmpeg
developers
built with Apple clang version 13.0.0 (clang-1300.0.29.30)
configuration:
libavutil 57. 42.100 / 57. 42.100
libavcodec 59. 52.102 / 59. 52.102
libavformat 59. 34.101 / 59. 34.101
libavdevice 59. 8.101 / 59. 8.101
libavfilter 8. 50.100 / 8. 50.100
libswscale 6. 8.112 / 6. 8.112
libswresample 4. 9.100 / 4. 9.100
Input #0, wav, from '96-24.wav':
Metadata:
encoder : Lavf59.34.101
Duration: 00:00:09.30, bitrate: 2304 kb/s
Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 96000 Hz, mono,
s32 (24 bit), 2304 kb/s
}}}
--
Ticket URL: <https://trac.ffmpeg.org/ticket/10038#comment:2>
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