Some streams had wrong values for the stream_id_extension, make sure
we only remember the valid ones.
For streams with PES_extension_field_length == 0, assume there's nothing
else.
For streams that state they have a TREF extension but don't have enough
data to store it, just assume it was produced by a non-compliant muxer
and skip the remaining data.
Only store remaining data in stream_id_extension_data instead of storing
data we already parse.
Helps with debugging issues. And also remove unused variable (opcr)
This will also allow us in the future to properly detect:
* random-access location (to enable keyframe observation and
potentially seeking
* discont location (to properly handle resets)
* splice location (to properly handle new stream changes)
additional_copy_info: need to get rid of the highest
bit, not the lowest one
program_packet_sequence_counter: also need to get rid
of the highest bit instead of multiplying with a random
value
original_stuff_length: want to AND 0x3f to extract the
lowest 6 bits, not multiply by it.
None of these fields are actually used though, so these
should not have caused any issues.
According to the specifications a PTS_DTS_flags value of 0x01 is forbidden.
... but there are some rare files out there that do that.
Instead of erroring out, let's warn, carry on parsing accordingly.
If the packet is really corrupted there are enough checks afterward to
detect that.
We in fact get the size of the header (including stuffing bytes), therefore
use that instead of trying to skip 0xff bytes ourselves since some media
streams do start with 0xff (like mpeg audio's initial 0xfff).
