We had two issues with the previous code:
1) We were badly handling PUSI-flagged packets. We were discarding the
initial data (if pointer != 0) whereas we should have been accumulating
it with the previous data (if there was a continuity of course).
=> First series of information loss
2) We were not checking whether there were more sections after the end
of one (i.e. when the following byte was not a stuff byte).
This fixes those two issues.
Fixes#677443https://bugzilla.gnome.org/show_bug.cgi?id=677443
* Only mpeg-ts section packetization remains.
* Improve code to detect duplicated sections as early as possible
* Add FIXME for various issues that need fixing (but are not regressions)
https://bugzilla.gnome.org/show_bug.cgi?id=702724
In some cases (NIT on highly-populated DVB-C operator for example), there
will be more than one section emitted for the same subtable and version
number.
In order not to lose those updates for the same version number, we checked
against the CRC of the previous section we parsed.
The problem is that, while it made sure we didn't lose any information, it
also meant that if the same section came back (same version, same CRC) later
on we would re-process it, re-parse it and re-emit it.
This version improves on that by keeping a list of previously observed CRC
for identical PID/subtable/version-number and will only process sections if
they really were never seen in the past (as opposed to just before).
On a 30s clip, this brings down the number of NIT section parsing from 4541
down to 663.
https://bugzilla.gnome.org/show_bug.cgi?id=614479
The overhead of creating/using 188 byte GstBuffer from GstAdapter
is too expensive.
We now peek the next packet, and provide a data/size which is only
valid until the packetizerpacket is cleared.
In addition, cleanup all the internal code to deal with that new
behaviour and remove double-checks which are no longer needed.
The section_length is now the corrected section_length (i.e. with
the additional 3 bytes).
Avoid using gst_adapter_prev_timestamp and instead track
the timestamp ourself.
Allows PCR<=>PTS<=>offset estimation/calculation
Right now the calculation is very naive, but can be extended later on
without disrupting the code in tsdemux/mpegtsbase
* Don't take into account packets that arrived at the same time as
previous ones for clock skew estimation
* Add convenience method for processing the next ts packet
buffer timestamps are converted to GstClockTime to cover pcr/pts wraps.
multiple pcr/pts wraps are handled with an index which ensures at most
a single pcr wraparound between two entries.
the last seen pcr is recorded to have a nearby index point for short seeks
resuming playback might be delayed if the postion is not a keyframe
TODO: replace manual packet scanning and parsing in the initial duration estimation
