When unboxing TKHD, the reader read int64 as trackId instead of int32. Thus unable to find matching timescale when doing TFHD unboxing. Therefore when parsing MDAT, the default timescale will be used which is 90000. All CC timestamps will then be incorrect.
This also fixes "Shaka Error MEDIA.VIDEO_ERROR (3,,PIPELINE_ERROR_DECODE: Failed to parse H.264 stream)" error when playing DASH MP4 H.264 streams with CEA-608 CC embedded. It's likely that the VDA bundled in Chromium-based browsers have already included EPB detection & prevention. If we let the player to remove the byte, VDA will complain about stream conformance.
Closes#3502
This is an MP4 Parser which extracts CEA-708 packets from Fragmented MP4 streams.
The Closed Caption Parser (shaka.media.ClosedCaptionParser) will own this MP4 Parser, and will initialize it and call it as shown. As data comes in, the parser will parse this data, and the caption packets data then be returned in a callback (on708Data), as shown. Here, a theoretical decoder (future pull request, mentioned as a Todo comment) will decode and extract the parsed captions from these packets.
Issue #2648
Álvaro Velad Galván
enson-choy
Muhammad Haris