Esa Kataja
022d131cd6
Bug #5: extractAudio invoked ffmpeg without `-map`, so default stream selection kept only one audio track from sources with multiple audio streams (e.g. eng/fra/jpn Blu-rays). It now enumerates audio streams from the streamLangs already fetched by the caller and runs one `ffmpeg -map 0🅰️<n>` per stream, writing audio.<n>.wav. Bug #11: the audio language metadata loop in encodeVideo computed the output index by counting source-side audio streams with a lower Index, which drifted when some source streams lacked a language tag. It now walks opusFiles in output order and looks up the language at the matching source-audio position via a sorted helper. These ship together because #11 was masked by #5: when only one audio track survived extraction, the broken index calculation never produced a visible misalignment. Fixing #5 alone would have caused multi-track outputs with shuffled language tags; both fixes are required to land correct multi-track output.