This is the decoder? where are such .wv files ? how it can be created?
There are two easy ways to create such files using the WavPack command-line program. The first would be to use the raw-pcm mode:
$ wavpack surround.raw --raw-pcm=48000,24,6 --channel-order=... (or --channel-order=FL,FR,...)
The other would be to simply encode a multichannel WAV file that has the channel mask in WAVEFORMATEXTENSIBLE set to the desired value.
Attached are three 6-channel files. One is full 5.1, one is just the front two channels assigned, and one is completely unassigned. Only surround.wv decodes/plays in FFmpeg.
You can verify the channel configuration with wvunpack:
david@pop-os-hp15:~/Projects/WavPack/cli$ wvunpack -ss surround.wv all-unassigned.wv front-only.wv
WVUNPACK Hybrid Lossless Audio Decompressor linux-gnu Version 5.7.0
Copyright (c) 1998 - 2024 David Bryant. All Rights Reserved.
surround.wv:
file name: surround.wv
file size: 2056838 bytes
source: 24-bit ints at 48000 Hz
channels: 6 (5.1 surround)
duration: 0:00:09.10
modalities: hybrid lossy, high, extra-6, dns
compression: 73.84%
ave bitrate: 1808 kbps
encoder version: 5
original md5: 88f981e653a6580825ab1ea46f31c468
source format: Microsoft RIFF with 'wav' extension
file wrapper: 104 byte RIFF header
all-unassigned.wv:
file name: all-unassigned.wv
file size: 2039996 bytes
source: 24-bit ints at 48000 Hz
channels: 6 (unassigned speakers)
duration: 0:00:09.10
modalities: hybrid lossy, high, extra-6, dns
compression: 74.05%
ave bitrate: 1793 kbps
encoder version: 5
original md5: 88f981e653a6580825ab1ea46f31c468
source format: Microsoft RIFF with 'wav' extension
file wrapper: 104 byte RIFF header
front-only.wv:
file name: front-only.wv
file size: 2047360 bytes
source: 24-bit ints at 48000 Hz
channels: 6 (FL,FR,...)
duration: 0:00:09.10
modalities: hybrid lossy, high, extra-6, dns
compression: 73.96%
ave bitrate: 1800 kbps
encoder version: 5
original md5: 88f981e653a6580825ab1ea46f31c468
source format: Microsoft RIFF with 'wav' extension
file wrapper: 104 byte RIFF header
**** 3 files successfully processed ****