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}
diff --git a/api/video_codecs/video_decoder_factory.h b/api/video_codecs/video_decoder_factory.h
index ef90809..0309553 100644
--- a/api/video_codecs/video_decoder_factory.h
+++ b/api/video_codecs/video_decoder_factory.h
@@ -39,10 +39,27 @@
// 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
// hardware acceleration.
- // See https://w3c.github.io/webrtc-svc/#scalabilitymodes* for a specification
- // of valid values for `scalability_mode`.
- // NOTE: QueryCodecSupport is currently an experimental feature that is
- // subject to change without notice.
+ // The parameter `reference_scaling` is used to query support for prediction
+ // across spatial layers. An example where support for reference scaling is
+ // needed is if the video stream is produced with a scalability mode that has
+ // 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(
const SdpVideoFormat& format,
absl::optional<std::string> scalability_mode) const {
