This is useful for seeking as we usually want to seek to the previous
keyframe. The keyframe detection is done by parsing the MPEG2
elementary stream and if a GOP or I-frame packet is found we
assume a keyframe in this edit unit.
Generate an index table for essence streams during playback
and make sure that only the correct essence elements are
used for played tracks.
Make it possible to have one essence stream used in multiple
playback tracks.
Fix some minor bugs.
When parsing an index table segment without a valid
primer pack in this partition only parse the static
local tags and ignore all dynamic ones.
This allows us to use index table segments in some
broken files.
Add an abstraction to represent essence tracks and
use this everywhere. This will later be used to keep
track of positions and to generate/handle seek tables.
Some random cleanup and renaming.
Allocate memory for the pos tables and slice offsets
of the index entries separately to a) fix alignment in
weird cases and b) to actually have something to free()
in the index table segment reset function.
Header metadata is finished after partition.header_byte_count
bytes after the first byte of the primer pack are handled.
After this there can only be index table segments, filler packets,
essence or the start of the next partition.
This fixes playback of some files that have non-standard metadata
packets in the header metadata.
Store all partitions & primer packs in memory for faster access.
This is later needed for fast seeking.
Pre-fill the list of partitions with the content of the random
index pack.
Don't parse metadata of an partition twice.
Store the MXF metadata in a hash table, keyed by the
instance UID. This simplifies resolval of the metadata
and makes looping over all metadata sets unnecessary
in most cases.
Additionally parse metadata always. If we already have
a metadata set with the same UID replace it only if
the new metadata set is from a later offset. This
fixes metadata parsing of files where following partitions
don't have a complete copy of the previous metadata.
