[FFmpeg-devel] [PATCH] Incorrect FourCC for HE-AAC in ISMV manifest

Yann Coupin yann.coupin+ffmpeg at gmail.com
Wed Dec 2 18:31:12 CET 2015


According to Microsoft's specs [1] (and after experiencing issues with the
Unified Streaming Platform [2] server), content encoded with HE-AAC audio
should use the AACH FourCC, but the value AACL is hardcoded in the manifest
generation code. So I created the attached patch to fix this. It passes
"test fate" and its effects can be seen using the commands bellow and
compatible server.

Although I tried to follow the patch submission checklist don't hesitate to
point errors or mistakes.


Sample command lines:

ffmpeg -i video.mp4 -vn -acodec libfdk_aac -profile:a aac_low -ab 128k -ar
44.1k -movflags isml -f ismv http://example.com/

FourCC of audio track in manifest is AACL as before

ffmpeg -i video.mp4 -vn -acodec libfdk_aac -profile:a aac_he -ab 64k -ar
44.1k -movflags isml -f ismv http://example.com/

FourCC is AACH

ffmpeg -i video.mp4 -vn -acodec libfdk_aac -profile:a aac_he_v2 -ab 64k -ar
44.1k -movflags isml -f ismv http://example.com/

FourCC is AACP

[1] https://msdn.microsoft.com/en-us/library/ff728116%28v=vs.95%29.aspx
[2] http://www.unified-streaming.com/
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