Change VideoDecoderFactory::QueryCodecSupport to use reference_scaling

All decoders are supposed to be able to decode all valid bitstreams
that can be produced by an encoder. In the cases where this is not
the case, reference_scaling better captures the cause of this than
scalability_mode which was used initially.

Bug: chromium:1187565
Change-Id: I21174077badf0fb9d90b1b58f003edac5b8ee0f2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/229184
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Johannes Kron <kron@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34800}
This commit is contained in:
Johannes Kron
2021-08-19 10:34:32 +02:00
committed by WebRTC LUCI CQ
parent d60b4ce33e
commit 3bb74f3800

View File

@ -39,10 +39,27 @@ class RTC_EXPORT VideoDecoderFactory {
// Query whether the specifed format is supported or not and if it will be // Query whether the specifed format is supported or not and if it will be
// power efficient, which is currently interpreted as if there is support for // power efficient, which is currently interpreted as if there is support for
// hardware acceleration. // hardware acceleration.
// See https://w3c.github.io/webrtc-svc/#scalabilitymodes* for a specification // The parameter `reference_scaling` is used to query support for prediction
// of valid values for `scalability_mode`. // across spatial layers. An example where support for reference scaling is
// NOTE: QueryCodecSupport is currently an experimental feature that is // needed is if the video stream is produced with a scalability mode that has
// subject to change without notice. // a dependency between the spatial layers. See
// https://w3c.github.io/webrtc-svc/#scalabilitymodes* for a specification of
// different scalabilty modes. NOTE: QueryCodecSupport is currently an
// experimental feature that is subject to change without notice.
virtual CodecSupport QueryCodecSupport(const SdpVideoFormat& format,
bool reference_scaling) const {
// Default implementation, query for supported formats and check if the
// specified format is supported. Returns false if `reference_scaling` is
// true.
CodecSupport codec_support;
codec_support.is_supported =
!reference_scaling && format.IsCodecInList(GetSupportedFormats());
return codec_support;
}
// TODO(kron): This function is deprecated and will be removed ASAP once
// downstream projects are updated to use `reference_scaling` instead of
// `scalability_mode`.
virtual CodecSupport QueryCodecSupport( virtual CodecSupport QueryCodecSupport(
const SdpVideoFormat& format, const SdpVideoFormat& format,
absl::optional<std::string> scalability_mode) const { absl::optional<std::string> scalability_mode) const {