Properly handle AAC/MP4 encoder delay

NEW
Unassigned

Status

()

Core
Audio/Video: Playback
P3
normal
a year ago
14 days ago

People

(Reporter: jya, Unassigned)

Tracking

Firefox Tracking Flags

(Not tracked)

Details

(Reporter)

Description

a year ago
See https://developer.apple.com/library/content/documentation/QuickTime/QTFF/QTFFAppenG/QTFFAppenG.html

Also found in ISO 14496-12.

AAC has traditionally had a default encoder delay set at 2112 frames. This is an implicit encoder.

Additionally, there's in the MP4 container an explicit encoding to define the encoder delay 
There are two boxes to handle such information:
sample group description box (sgpd) and
sample-to-group (sbgp)

This is in additional to an eventual edit list.

Stagefright appears to have handling for all of those and set some keys
kKeyEncoderDelay
kKeyEncoderPadding

we should handle this with the rust demuxer, and then modify all the decoders to trim the frames on both ends.
(Reporter)

Updated

a year ago
Duplicate of this bug: 1320652
Priority: -- → P3
(Reporter)

Updated

a year ago
See Also: → bug 1345756
You need to log in before you can comment on or make changes to this bug.