Bug 310845
| Summary: | [MSE][GStreamer] Advertise AC4 in systems supporting it | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Alicia Boya García <aboya> |
| Component: | WebKitGTK | Assignee: | Alicia Boya García <aboya> |
| Status: | NEW | ||
| Severity: | Normal | CC: | bugs-noreply |
| Priority: | P2 | ||
| Version: | WebKit Nightly Build | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
Alicia Boya García
This patch enables Dolby AC-4 support in systems that have a GStreamer
decoder that supports it. As of writing AC4 support is still not mature
in desktop but it is present in some set top boxes.
The changes involve adding support for the MIME type and codec strings
in MSE and whitelisting the caps in WebKitThunderDecryptorGStreamer. The
codec string is also checked for format correctness and presentation
version support.
Unfortunately, as of writing the existing GStreamer decoders don't have
a established way of querying AC-4 support levels in a fine grained
manner.
This patch will accept codec strings for presentation version 1.
Presentation version 1 is the minimum version supported by bitstream
version 2, which is the only bitstream version that is part of the
current Dolby AC-4 Kit (1.5) test signals. This combination is also the
only one supported in CMAF according to the current version of the AC-4
spec (ETSI TS 103 190-2 V1.3.1, 2025-07).
This is understood to be a reasonable baseline for what is commonly
supported for a contemporary AC-4 decoder. It is possible however that
in the future we need to add support for e.g. environment variables
to further customize support level, assuming that by then there is still
no way of querying the support level from WebKit.
Original author: Andrzej Surdej <Andrzej_Surdej@comcast.com>
See: https://github.com/WebPlatformForEmbedded/WPEWebKit/pull/1641
| Attachments | ||
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| Add attachment proposed patch, testcase, etc. |
Alicia Boya García
Pull request: https://github.com/WebKit/WebKit/pull/61449