avcodec/jpeglsenc: Avoid intermediate buffer, allow user-supplied buffers

Up until now, the JPEG-LS encoder allocated a worst-case-sized packet
at the beginning of each encode2 call; then it wrote the packet header
into its destination buffer and encoded the actual packet data;
said data is written into another worst-case-sized buffer, because it
needs to be escaped before being written into the packet buffer.
Finally, because the packet buffer is worst-case-sized, the generic
code copies the actually used part into a fresh buffer.

This commit changes this: Allocating the packet and writing the header
into it is deferred until the actual data has been encoded and its size
is known. This gives a good upper bound for the needed size of the packet
buffer (the upper bound might be 1/15 too large) and so one can avoid the
implicit intermediate buffer and support user-supplied buffers by using
ff_get_encode_buffer().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

0 files changed, 0 insertions, 0 deletions