Currently, a fragment's unit array is constantly reallocated during
splitting of a packet. This commit changes this: One can keep the units
array by distinguishing between the number of allocated and the number
of valid units in the units array.
The more units a packet is split into, the bigger the benefit.
So MPEG-2 benefits the most; for a video coming from an NTSC-DVD
(usually 32 units per frame) the average cost of cbs_insert_unit (for a
single unit) went down from 6717 decicycles to 450 decicycles (based
upon 10 runs with 4194304 runs each); if each packet consists of only
one unit, it went down from 2425 to 448; for a H.264 video where most
packets contain nine units, it went from 4431 to 450.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Using the value of buffering frames inferred from the old level is
not a sensible approach when one wants to guess the level.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>
profile_idc for level 1b should be 11, not 10.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@googlemail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>
This makes it easier for users of the CBS API to get alloc/free right -
all subelements use the buffer API so that it's clear how to free them.
It also allows eliding some redundant copies: the packet -> fragment copy
disappears after this change if the input packet is refcounted, and more
codec-specific cases are now possible (but not included in this patch).
This is able to modify some header metadata found in the SPS/VUI,
and can also add/remove AUDs and insert user data in SEI NAL units.
(cherry picked from commit 9e93001b61)
(cherry picked from commit c42b62d1f9)
Whether the udu string should be freed depends on whether the SEI it
gets added to was created internally by cbs or externally by the bsf.
The current code frees it twice in the former case.
Decai Lin
Andreas Rheinhardt
Mark Thompson
James Almer
Jun Zhao