The example playlist on https://devstreaming-cdn.apple.com/videos/streaming/examples/bipbop_16x9/bipbop_16x9_variant.m3u8 points at an audio track at the relative URI "alternate_audio_aac_sinewave/prog_index.m3u8".
However, trying to download https://devstreaming-cdn.apple.com/videos/streaming/examples/bipbop_16x9/alternate_audio_aac_sinewave/prog_index.m3u8 with curl gives the response
<?xml version="1.0" encoding="UTF-8"?>
I see this comment about that track: "The second alternate audio demonstrates the use of an alternate audio option, but was not designed as a true sync verification."
Do you mean to say that there simply is no alternate audio available?
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