pan audiofilter regression

[Jose Peirote]

Summary of the bug:
the pan audiofilter work fine in 4.4 version with a simple downmix:

ffmpeg -i 8v341.dts -filter_complex "asplit [f][s]; [f] pan=FL+FR+FC+LFE|FL=FL|FR=FR|FC=FC|LFE=LFE [r]; [s] pan=SL+SR|c0=0.5*c4+0.5*c6|c1=0.5*c5+0.5*c7 [d]; [r][d] amerge [a]" -map "[a]" -acodec pcm_s24le 8v341_44.wav
ffmpeg version n4.4.3-3-gb48951bd29-20230204 Copyright (c) 2000-2022 the FFmpeg developers

built with gcc 12.2.0 (crosstool-NG 1.25.0.90_cf9beb1)
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100

...
Input #0, dts, from 'C:\tmp\8v341.dts':

Stream #0:0: Audio: dts (DTS-HD MA), 48000 Hz, 7.1, s32p (24 bit)

[Parsed_pan_1 @ 00000201ed440dc0] Pure channel mapping detected: 0 1 2 3
Output #0, wav, to 'C:\tmp\8v341_144.wav':

Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 5.1(side), s32 (24 bit), 6912 kb/s

encoder : Lavc58.134.100 pcm_s24le

But using a 5.1 version:

ffmpeg -i 8v341.dts -filter_complex "asplit [f][s]; [f] pan=FL+FR+FC+LFE|FL=FL|FR=FR|FC=FC|LFE=LFE [r]; [s] pan=SL+SR|c0=0.5*c4+0.5*c6|c1=0.5*c5+0.5*c7 [d]; [r][d] amerge [a]" -map "[a]" -acodec pcm_s24le 8v341_51.wav
ffmpeg version n5.1.2-11-g30d432f205-20230204 Copyright (c) 2000-2022 the FFmpeg developers

built with gcc 12.2.0 (crosstool-NG 1.25.0.90_cf9beb1)
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100

...
Input #0, dts, from 'C:\tmp\8v341.dts':

Stream #0:0: Audio: dts (DTS-HD MA), 48000 Hz, 7.1, s32p (24 bit)

[Parsed_pan_1 @ 000001d1d89f05c0] [SWR @ 000001d1d8a400c0] Input channel layout has a different number of channels than the number of used channels, ignoring layout ????
[Parsed_pan_1 @ 000001d1d89f05c0] Pure channel mapping detected: 0 1 2 3
Output #0, wav, to 'C:\tmp\8v341.dtshd_.dts_151.wav':

Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 5.1(side), s32, 6912 kb/s

encoder : Lavc59.37.100 pcm_s24le

there are a new and wrong message and the output is wrong (LFE input channel mixed 50% in FL and FR channels, empty LFE output channel.
See the image

[Elon Musk]

Fixed in 93a9ee7afd7bf2e019490117f1bada30724a0200