Change #248052

Comments

hlsenc, dashenc: Share the routine for generating a codec string
The one in dashenc was added in
fe5e6e34c05e274f98528be4f77f3c474473f977, while the one in hlsenc
was added later in 0afa171f25bc9b613a77328182e54d6e781269d3. Both
have had various additions on top; merge both implementations
into one shared. (Notable additions in
060e74e2a970bb12ab138cfff5aaff8d132ffc65,
1cf2f040e34bbfedde60ff3d91b2f7b770aca85b,
a2b1dd0ce301450a47c972745a6b33c4c273aa5d and
797f0b27c175022d896e46db4ac2873e3e0a70af.)

For H264/avc1, use the implementation from hlsenc (which doesn't
use temporary allocations). For most other codecs, use the
only implementation from whichever had one.

The original dashenc implementation tried to be generic based
on RFC 6381, looking up codec tags in ff_codec_movvideo_tags
or ff_codec_movaudio_tags, and doing specific extra additions
for "mp4a" and "mp4v". In practice, only AV_CODEC_ID_AAC
and AV_CODEC_ID_MPEG4 ever mapped to these; simplify this to
a more straightforward codec id based handling, and merge
with the AAC profile based code from hlsenc.

There's a slight behaviour difference from the old one in
dashenc; if there's no code for a specific codec ID, we previously
just output what we matched from the mov tag tables, but now
we won't output anything. But most commonly used codecs in
DASH should be covered here.

Changed files

• libavformat/Makefile
• libavformat/codecstring.c
• libavformat/dashenc.c
• libavformat/hlsenc.c
• libavformat/internal.h