MusicBrainz service in Amarok uses deprecated code that was removed in ffmpeg 5.x.
E.g.:
/<<PKGBUILDDIR>>/src/musicbrainz/MusicDNSAudioDecoder.cpp:203:79: error: invalid conversion from ‘AVCodec**’ to ‘const AVCodec**’ [-fpermissive]
/<<PKGBUILDDIR>>/src/musicbrainz/MusicDNSAudioDecoder.cpp:218:51: error: ‘AVStream’ {aka ‘struct AVStream’} has no member named ‘codec’
/<<PKGBUILDDIR>>/src/musicbrainz/MusicDNSAudioDecoder.cpp:254:30: error: ‘avcodec_decode_audio4’ was not declared in this scope; did you mean ‘avcodec_decode_subtitle2’?
/<<PKGBUILDDIR>>/src/musicbrainz/MusicDNSAudioDecoder.cpp:277:9: error: ‘av_free_packet’ was not declared in this scope; did you mean ‘av_new_packet’?
/<<PKGBUILDDIR>>/src/musicbrainz/MusicDNSAudioDecoder.cpp:283:5: error: ‘av_free_packet’ was not declared in this scope; did you mean ‘av_new_packet’?