ebur128 with peak=true has broken output audio channels

[John Warburton]

Summary of the bug:
How to reproduce:

% ffmpeg -v debug -i .\alman.m4a -af "ebur128=peak=true" ebur128test.mp4

This is a stereo AAC file with 44.1kHz sampling rate, going into ffmpeg version N-106566-ge254af3154, built with gcc for mingw-w64 on April 11th, 2022.

With peak=true, we get (see below for fuller output):

[SWR @ 00000235a1c6c4c0] Input channel layout "0 channels" is invalid or unsupported.
[SWR @ 00000235a1c6c4c0] Output channel layout "0 channels" is invalid or unsupported.
[SWR @ 00000235a1c6c4c0] Using dblp internally between filters
[SWR @ 00000235a1c6c4c0] Input channel count and layout are unset
[Parsed_ebur128_0 @ 00000235a12b3840] Failed to configure output pad on Parsed_ebur128_0
...
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0

Now, here is a fuller grab of the output:

[Parsed_ebur128_0 @ 00000235a12b3840] Setting 'peak' to value 'true'
[Parsed_ebur128_0 @ 00000235a12b3840] EBU +9 scale
[graph_0_in_0_0 @ 00000235a12b2c80] Setting 'time_base' to value '1/44100'
[graph_0_in_0_0 @ 00000235a12b2c80] Setting 'sample_rate' to value '44100'
[graph_0_in_0_0 @ 00000235a12b2c80] Setting 'sample_fmt' to value 'fltp'
[graph_0_in_0_0 @ 00000235a12b2c80] Setting 'channel_layout' to value 'stereo'
[graph_0_in_0_0 @ 00000235a12b2c80] tb:1/44100 samplefmt:fltp samplerate:44100 chlayout:stereo
[format_out_0_0 @ 00000235a12a6700] Setting 'sample_fmts' to value 'fltp'
[format_out_0_0 @ 00000235a12a6700] Setting 'sample_rates' to value '96000|88200|64000|48000|44100|32000|24000|22050|16000|12000|11025|8000|7350'
[Parsed_ebur128_0 @ 00000235a12b3840] auto-inserting filter 'auto_aresample_0' between the filter 'graph_0_in_0_0' and the filter 'Parsed_ebur128_0'
[format_out_0_0 @ 00000235a12a6700] auto-inserting filter 'auto_aresample_1' between the filter 'Parsed_ebur128_0' and the filter 'format_out_0_0'
[AVFilterGraph @ 00000235a12a5c80] query_formats: 4 queried, 3 merged, 6 already done, 0 delayed
[auto_aresample_0 @ 00000235a1c11bc0] [SWR @ 00000235a1c11d40] Using fltp internally between filters
[auto_aresample_0 @ 00000235a1c11bc0] ch:2 chl:stereo fmt:fltp r:44100Hz -> ch:2 chl:stereo fmt:dbl r:44100Hz
[SWR @ 00000235a1c6c4c0] Input channel layout "0 channels" is invalid or unsupported.
[SWR @ 00000235a1c6c4c0] Output channel layout "0 channels" is invalid or unsupported.
[SWR @ 00000235a1c6c4c0] Using dblp internally between filters
[SWR @ 00000235a1c6c4c0] Input channel count and layout are unset
[Parsed_ebur128_0 @ 00000235a12b3840] Failed to configure output pad on Parsed_ebur128_0
[Parsed_ebur128_0 @ 00000235a12b3840] Summary:

  Integrated loudness:
    I:         -70.0 LUFS
    Threshold:   0.0 LUFS

  Loudness range:
    LRA:         0.0 LU
    Threshold:   0.0 LUFS
    LRA low:     0.0 LUFS
    LRA high:    0.0 LUFS

  True peak:
    Peak:       -inf dBFS
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:0
[AVIOContext @ 00000235a12aae00] Statistics: 0 bytes written, 0 seeks, 0 writeouts
[AVIOContext @ 00000235a1280440] Statistics: 74449 bytes read, 2 seeks
Conversion failed!

With peak=sample or any other value, conversion proceeds normally.

[Elon Musk]

Fixed in 13fe148c319d758c0d8be4073905cfa79ed3bfc6

[John Warburton]

Replying to Elon Musk:

Fixed in 13fe148c319d758c0d8be4073905cfa79ed3bfc6

Thank you for spotting this!

Much appreciated. Will return local compile to git master now.
JW