Some hardware video decode acceleration API (VA-API, DXVA) require
a bit count to the first macroblock, minus the number of emulation
prevention bytes. So, instead of having the consumer of the library
scan the slice_header() again, just record that number while parsing.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
https://bugzilla.gnome.org/show_bug.cgi?id=671203
The entries were not filled in linearly and the termination was not
recorded either. Now, the actual number of modifications is recorded
similarly to dec_ref_pic_marking(). i.e. an explicit counter instead
of storing the termination value in the array.
https://bugzilla.gnome.org/show_bug.cgi?id=668192
This is useful for cases where the caller *knows* that the provided
input contains a whole NALU and can therefore avoid:
* the expensive checks for the next start code (which won't be present)
* delaying the input parsing (since we would need the next incoming NALU
in order for the parsing code to detect the next start code)
https://bugzilla.gnome.org/show_bug.cgi?id=665584
