Multichannel AAC Audio in Fragmented MP4

Every sample encoded with FFMPEG 6.0's native AAC encoder.

Each sample is loaded with two methods - as an HTML5 Audio element, and via Media Source Extensions (the "HTML Audio" and "MSE" columns, respectively).

ffmpeg CLI: for f in *.wav; do ffmpeg -loglevel info -i "$f" -c:a aac -movflags faststart+empty_moov+default_base_moof "${f%.wav}.m4a"; done > log.txt 2>&1

ffmpeg log

Different channel layouts require different signaling, the method used is indicated by the PCE column:

• false indicates that the channel layout is signaled using the channelConfiguration field within the AudioSpecificConfig.
• true indicates that the channel layout is signaled via Program Config Element in the GASpecificConfig.

In all cases, the channel layout is signaled within the Media Initialization Segment.

The channels represented in each layout are:

• 2.0 Front Left, Front Right
• 2.1 Front Left, Front Right, LFE
• 3.0 Front Left, Front Right, Front Center
• 3.1 Front Left, Front Right, Front Center, LFE
• 4.0 Front Left, Front Right, Front Center, Rear Center
• 4.1 Front Left, Front Right, Front Center, Rear Center, LFE
• 5.0 Front Left, Front Right, Front Center, Rear Left, Rear Right
• 5.1 Front Left, Front Right, Front Center, Rear Left, Rear Right, LFE
• 6.0 Front Left, Front Right, Front Center, Rear Center, Side Left, Side Right
• 6.1 Front Left, Front Right, Front Center, Rear Center, Side Left, Side Right, LFE
• 7.0 Front Left, Front Right, Front Center, Rear Left, Rear Right, Side Left, Side Right
• 7.1 Front Left, Front Right, Front Center, Rear Left, Rear Right, Side Left, Side Right, LFE

The layouts listed don't necessarily represent the channel ordering.