Substream IDs?

[Tyris]

Where are the audio substream IDs in IFOs? I can't seem to find them on mpucoder's site, but IfoEdit definitely shows them.

[mpucoder]

The audio attributes for the title set begin at offset 0x204, and are in order from stream 0 to 7. The substream number is derived from the audio stream number and the encoding type. For AC3 ad 0x80, for DTS add 0x88, and for LPCM add 0xA0.

But wait - there's more. These are just the definitions of what each audio stream, if present, contains. In each PGC starting at offset 0x0C is the map of streams for that program to the corresponding audio stream number.

This allows many audio stream types to be defined. Example, a title set has a movie with AC3 5.1, and a trailer with AC3 2.0, the attribute bytes at 204 would define audio stream 0 as AC3 5.1 and audio stream 1 as AC3 2.0, the PGC for the trailer would only list one audio stream, stream 1 (substream 81, since it is AC3)

Now it just occurred to me you might be asking where the substream id is in private stream 1. That is located just after the PES header (01BD). To make things simple when scanning these just look at byte 8, it gives the number of additional bytes in the PES extension that you need to skip.

[Tyris]

Thanks! :) I was staring at the audio attribute section for a quite a while, but I guess I wasn't picking up on the addition needed for substream IDs. You may want to give a hint about this in the IFO section... I remember something similar when you describe the actual stream content, but not from an IFO standpoint.