mirror of
https://github.com/mollyim/webrtc.git
synced 2025-05-19 00:27:51 +01:00
3bb74f3800
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}
85 lines
3.2 KiB
C++
85 lines
3.2 KiB
C++
/*
|
|
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
#ifndef API_VIDEO_CODECS_VIDEO_DECODER_FACTORY_H_
|
|
#define API_VIDEO_CODECS_VIDEO_DECODER_FACTORY_H_
|
|
|
|
#include <memory>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "absl/types/optional.h"
|
|
#include "api/video_codecs/sdp_video_format.h"
|
|
#include "rtc_base/system/rtc_export.h"
|
|
|
|
namespace webrtc {
|
|
|
|
class VideoDecoder;
|
|
|
|
// A factory that creates VideoDecoders.
|
|
// NOTE: This class is still under development and may change without notice.
|
|
class RTC_EXPORT VideoDecoderFactory {
|
|
public:
|
|
struct CodecSupport {
|
|
bool is_supported = false;
|
|
bool is_power_efficient = false;
|
|
};
|
|
|
|
// Returns a list of supported video formats in order of preference, to use
|
|
// for signaling etc.
|
|
virtual std::vector<SdpVideoFormat> GetSupportedFormats() const = 0;
|
|
|
|
// 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.
|
|
// 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 {
|
|
// Default implementation, query for supported formats and check if the
|
|
// specified format is supported. Returns false if scalability_mode is
|
|
// specified.
|
|
CodecSupport codec_support;
|
|
if (!scalability_mode) {
|
|
codec_support.is_supported = format.IsCodecInList(GetSupportedFormats());
|
|
}
|
|
return codec_support;
|
|
}
|
|
|
|
// Creates a VideoDecoder for the specified format.
|
|
virtual std::unique_ptr<VideoDecoder> CreateVideoDecoder(
|
|
const SdpVideoFormat& format) = 0;
|
|
|
|
virtual ~VideoDecoderFactory() {}
|
|
};
|
|
|
|
} // namespace webrtc
|
|
|
|
#endif // API_VIDEO_CODECS_VIDEO_DECODER_FACTORY_H_
|