Skip to content

Add Extended HE-AAC to AAC WebCodecs Registration #3

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Djuffin wants to merge 3 commits into
base: main
Choose a base branch
from
+20 −7
Open

Add Extended HE-AAC to AAC WebCodecs Registration #3

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
7b6070f
Add Extended HE-AAC to AAC WebCodecs Registration
google-labs-jules[bot] Mar 10, 2026
aeb58fd
Address PR comments on AudioDecoderConfig description
google-labs-jules[bot] Mar 10, 2026
71f8e4a
Implement PR feedback for Extended HE-AAC
google-labs-jules[bot] Mar 10, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 20 additions & 7 deletions aac_codec_registration.src.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -36,10 +36,22 @@
<pre class='biblio'>
{
"iso14496-3": {
"href": "https://www.iso.org/standard/53943.html",
"title": "ISO/IEC 14496-3:2009 - Information technology — Coding of audio-visual objects — Part 3: Audio",
"href": "https://www.iso.org/standard/76383.html",
"title": "ISO/IEC 14496-3:2019 - Information technology — Coding of audio-visual objects — Part 3: Audio",
"publisher": "ISO",
"date": "2009-09"
"date": "2019-12"
},
"iso23003-3": {
"href": "https://www.iso.org/standard/76385.html",
"title": "ISO/IEC 23003-3:2020 - Information technology — MPEG audio technologies — Part 3: Unified speech and audio coding",
"publisher": "ISO",
"date": "2020-06"
},
"iso23003-4": {
"href": "https://www.iso.org/standard/89036.html",
"title": "ISO/IEC 23003-4:2025 - Information technology — MPEG audio technologies — Part 4: Dynamic range control",
"publisher": "ISO",
"date": "2025-03"
}
}
</pre>
Expand All @@ -54,6 +66,7 @@
- `"mp4a.40.5"` — MPEG-4 HE-AAC v1 (AAC LC + SBR)
- `"mp4a.40.05"` — MPEG-4 HE-AAC v1 (AAC LC + SBR), leading 0 for Aud-OTI compatibility
- `"mp4a.40.29"` — MPEG-4 HE-AAC v2 (AAC LC + SBR + PS)
- `"mp4a.40.42"` — Extended HE-AAC (xHE-AAC) (MPEG-D USAC + MPEG-D DRC) as defined in [[iso23003-3]] and [[iso23003-4]]
- `"mp4a.67"` — MPEG-2 AAC LC

EncodedAudioChunk data {#encodedaudiochunk-data}
Expand All @@ -66,14 +79,14 @@
If the bitstream is in {{AacBitstreamFormat/aac}} format, the
{{EncodedAudioChunk/[[internal data]]}} of {{EncodedAudioChunk}}s are expected
to be a raw AAC frame (syntax element `raw_data_block()`), as described in
section 4.4.2.1 of [[iso14496-3]].
section 4.4.2.1 of [[iso14496-3]]. Extended HE-AAC must be in {{AacBitstreamFormat/aac}} format.

AudioDecoderConfig description {#audiodecoderconfig-description}
================================================================

If {{AudioDecoderConfig/description}} is present, it is assumed to a
`AudioSpecificConfig` as defined in [[iso14496-3]] section 1.6.2.1, Table 1.15,
and the bitstream is assumed to be in {{AacBitstreamFormat/aac}}.
If {{AudioDecoderConfig/description}} is present, it is assumed to be an
`AudioSpecificConfig` as defined in [[iso14496-3]] section 1.6.2.1, Table 1.19,
and the bitstream is assumed to be in {{AacBitstreamFormat/aac}} format.

If the {{AudioDecoderConfig/description}} is not present, the bitstream is
assumed to be in {{AacBitstreamFormat/adts}} format.
Expand Down