Audiowmark fails to build on Arch

[tim-janik]

Recently, Arch has upgraded to ffmpeg-7, which removed deprecated APIs from ffmpeg-6.1..

Atm, building the repo on Arch fails as follows:

$ docker build -t audiowmark-arch -f misc/Dockerfile-arch .
15.97 g++ -std=gnu++14 -DHAVE_CONFIG_H -I. -I..    -I/usr/include/opus     -g -O2 -Wall -pthread -MT testrandom.o -MD -MP -MF .deps/testrandom.Tpo -c -o testrandom.o testrandom.cc
15.99 hlsoutputstream.cc: In member function ‘Error HLSOutputStream::add_stream(const AVCodec**, AVCodecID)’:
15.99 hlsoutputstream.cc:116:26: error: ‘av_get_channel_layout’ was not declared in this scope; did you mean ‘set_channel_layout’?
15.99   116 |   uint64_t want_layout = av_get_channel_layout (m_channel_layout.c_str());
15.99       |                          ^~~~~~~~~~~~~~~~~~~~~
15.99       |                          set_channel_layout
15.99 hlsoutputstream.cc:119:10: error: ‘AVCodecContext’ {aka ‘struct AVCodecContext’} has no member named ‘channel_layout’; did you mean ‘ch_layout’?
15.99   119 |   m_enc->channel_layout = want_layout;
15.99       |          ^~~~~~~~~~~~~~
15.99       |          ch_layout

> pacman -Q
0.452 ffmpeg 2:7.0.2-1