DASH reads the AudioChannelConfiguration scheme (Dolby mask, CICP index incl. immersive layouts, channel count); HLS and ISM counts map 6/7/8 to 5.1/6.1/7.1.
Fix DASH SegmentTimeline negative @r and Pattern, TTML sidecar sets with no contentType, HLS CHANNELS identifiers and Dolby channel masks; test against 408 public DASH/HLS/ISM manifests.
parse_channels rejected a three-figure layout, so a remote download crashed rebuilding the track from JSON. Add channel_total so --channels can compare either form.