before:
419022 decicycles in assemble_fragment, 2047 runs, 1 skips
after:
104621 decicycles in assemble_fragment, 2045 runs, 3 skips
Benched with a 2 minutes long 720x480 DVD mpeg2 sample.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
This saves one malloc + memcpy per packet
The CodedBitstreamFragment buffer is padded to follow the requirements
of AVPacket.
Reviewed-by: jkqxz
Signed-off-by: James Almer <jamrial@gmail.com>
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).