[FFmpeg-trac] #6638(avfilter:new): aresample does not work for unknown channel layouts

[FFmpeg]

#6638: aresample does not work for unknown channel layouts
-------------------------------------+-------------------------------------
             Reporter:  CoRoNe       |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  avfilter
              Version:  git-master   |               Resolution:
             Keywords:  aresample    |               Blocked By:
  unknown channel layouts            |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Changes (by CoRoNe):

 * version:  unspecified => git-master


Comment:

 Today I've had another look at this. (FFmpeg used:
 ffmpeg-N-90853-g3914a76)

 {{{
 ffmpeg -v 40 -f lavfi -i sine -af "loudnorm" -f null NUL
 [...]
 [graph_0_in_0_0 @ 05b35e00] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_loudnorm_0 @ 05b35880] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_loudnorm_0'
 [format_out_0_0 @ 05b36dc0] auto-inserting filter 'auto_resampler_1'
 between the filter 'Parsed_loudnorm_0' and the filter 'format_out_0_0'
 [auto_resampler_0 @ 05b37ac0] ch:1 chl:mono fmt:s16 r:44100Hz -> ch:1
 chl:mono fmt:dbl r:192000Hz
 [auto_resampler_1 @ 05b37600] ch:1 chl:mono fmt:dbl r:192000Hz -> ch:1
 chl:mono fmt:s16 r:192000Hz
 }}}
 To mimic the same output (sample-format and sample-rate wise):
 {{{
 ffmpeg -v 40 -f lavfi -i sine -af "aformat=dbl:192000" -f null NUL
 [...]
 [graph_0_in_0_0 @ 05b36040] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_aformat_0 @ 05b358c0] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_aformat_0'
 [format_out_0_0 @ 05b36dc0] auto-inserting filter 'auto_resampler_1'
 between the filter 'Parsed_aformat_0' and the filter 'format_out_0_0'
 [auto_resampler_0 @ 05b37900] ch:1 chl:mono fmt:s16 r:44100Hz -> ch:1
 chl:mono fmt:dbl r:192000Hz
 [auto_resampler_1 @ 05b37440] ch:1 chl:mono fmt:dbl r:192000Hz -> ch:1
 chl:mono fmt:s16 r:192000Hz
 }}}
 Adding `aresample` to the filter chain results in the same error as with
 the `loudnorm` filter:
 {{{
 ffmpeg -v 40 -f lavfi -i sine -af "aformat=dbl:192000,aresample=44100" -f
 null NUL
 [...]
 [graph_0_in_0_0 @ 05b4ab40] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_aformat_0 @ 05b358c0] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_aformat_0'
 [Parsed_aresample_1 @ 05b360c0] Cannot select channel layout for the link
 between filters Parsed_aresample_1 and format_out_0_0.
 Error reinitializing filters!
 Failed to inject frame into filter network: Invalid argument
 Error while processing the decoded data for stream #0:0
 }}}
 This can be fixed with `ocl=mono`:
 {{{
 ffmpeg -v 40 -f lavfi -i sine -af
 "aformat=dbl:192000,aresample=44100:ocl=mono" -f null NUL
 [...]
 [graph_0_in_0_0 @ 05b4ac40] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_aformat_0 @ 05b358c0] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_aformat_0'
 [auto_resampler_0 @ 05b4c980] ch:1 chl:mono fmt:s16 r:44100Hz -> ch:1
 chl:mono fmt:dbl r:192000Hz
 [Parsed_aresample_1 @ 05b360c0] ch:1 chl:mono fmt:dbl r:192000Hz -> ch:1
 chl:mono fmt:s16 r:44100Hz
 }}}
 ...but the strange thing is that it appears the channel layout only gets
 lost with this particular format (double, 192000Hz), because `ocl=mono`
 isn't needed when I only change the sample-format or the sample-rate
 separately:
 {{{
 ffmpeg -v 40 -f lavfi -i sine -af
 "aformat=sample_rates=192000,aresample=44100" -f null NUL
 [...]
 [graph_0_in_0_0 @ 05b4aa00] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_aformat_0 @ 05b358c0] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_aformat_0'
 [auto_resampler_0 @ 05b4c800] ch:1 chl:mono fmt:s16 r:44100Hz -> ch:1
 chl:mono fmt:s16 r:192000Hz
 [Parsed_aresample_1 @ 05b35e80] ch:1 chl:mono fmt:s16 r:192000Hz -> ch:1
 chl:mono fmt:s16 r:44100Hz
 }}}
 {{{
 ffmpeg -v 40 -f lavfi -i sine -af
 "aformat=sample_fmts=dbl,aresample=44100" -f null NUL
 [...]
 [graph_0_in_0_0 @ 05b4a9c0] tb:1/44100 samplefmt:s16 samplerate:44100
 chlayout:0x4
 [Parsed_aformat_0 @ 05b358c0] auto-inserting filter 'auto_resampler_0'
 between the filter 'graph_0_in_0_0' and the filter 'Parsed_aformat_0'
 [auto_resampler_0 @ 05b4c780] ch:1 chl:mono fmt:s16 r:44100Hz -> ch:1
 chl:mono fmt:dbl r:44100Hz
 [Parsed_aresample_1 @ 05b35e80] ch:1 chl:mono fmt:dbl r:44100Hz -> ch:1
 chl:mono fmt:s16 r:44100Hz
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/6638#comment:2>
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