Add extended HE-AAC to the AAC WebCodecs Registration#930
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Add extended HE-AAC to the AAC WebCodecs Registration#930
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Adds "mp4a.40.42" (Extended HE-AAC) to the list of fully qualified codec strings, along with a note that Extended HE-AAC should use the "aac" bitstream format. Updates the [ISO14496-3] reference to the 2019 edition and adds new bibliographic references for [ISO23003-3] (USAC) and [ISO23003-4] (DRC). Co-authored-by: Djuffin <132926+Djuffin@users.noreply.github.com>
Fixes the grammar ("assumed to a" -> "assumed to be an"), updates
the AudioSpecificConfig table reference from 1.15 to 1.19, and
adds "format" after {{AacBitstreamFormat/aac}} as requested by the
reviewer.
Co-authored-by: Djuffin <132926+Djuffin@users.noreply.github.com>
dalecurtis
reviewed
Mar 10, 2026
aac_codec_registration.src.html
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| - `"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 (MPEG-D USAC + MPEG-D DRC) as defined in [[iso23003-3]] and [[iso23003-4]] |
Contributor
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I'd add (xHE-AAC) in parenthesis, but up to you.
aac_codec_registration.src.html
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| {{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 shall be in {{AacBitstreamFormat/aac}} format. |
Contributor
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I forget if we're supposed to use "must" now.
- Adds "(xHE-AAC)" to the display name of mp4a.40.42 - Changes "shall" to "must" in EncodedAudioChunk data requirement Co-authored-by: Djuffin <132926+Djuffin@users.noreply.github.com>
dalecurtis
approved these changes
Mar 10, 2026
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Adds "mp4a.40.42" (Extended HE-AAC) to the list of fully qualified codec strings, along with a note that Extended HE-AAC should use the "aac" bitstream format. Updates the [ISO14496-3] reference to the 2019 edition and adds new bibliographic references for [ISO23003-3] (USAC) and [ISO23003-4] (DRC).
Addresses Issue #929