demux: replace deprecated usage of stack allocated AVPackets

In the previous change, I replaced the callsites that used
`av_init_packet`, but there are a handful of places that use stack
allocated packets with no initialisation.

In one case, I just switched to heap allocation as it's only done once
per stream at most.

In the other case, I removed our usage of the AVPackets as a
convenience mechanism to transfer data into a heap allocated packet.
Instead, I inlined the data copying.

0 files changed, 0 insertions, 0 deletions