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0e61fdd27c
Bug: webrtc:12338 Change-Id: Ib97b2c3d64dbd895f261ffa76a2e885bd934a87f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226940 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34554}
120 lines
4.5 KiB
C++
120 lines
4.5 KiB
C++
/*
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* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_
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#define API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_
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#include <memory>
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#include <string>
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#include <vector>
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#include "absl/types/optional.h"
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#include "api/units/data_rate.h"
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#include "api/video_codecs/sdp_video_format.h"
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namespace webrtc {
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class VideoEncoder;
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// A factory that creates VideoEncoders.
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// NOTE: This class is still under development and may change without notice.
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class VideoEncoderFactory {
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public:
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// TODO(magjed): Try to get rid of this struct.
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struct CodecInfo {
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// `has_internal_source` is true if encoders created by this factory of the
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// given codec will use internal camera sources, meaning that they don't
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// require/expect frames to be delivered via webrtc::VideoEncoder::Encode.
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// This flag is used as the internal_source parameter to
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// webrtc::ViEExternalCodec::RegisterExternalSendCodec.
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bool has_internal_source = false;
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};
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struct CodecSupport {
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bool is_supported = false;
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bool is_power_efficient = false;
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};
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// An injectable class that is continuously updated with encoding conditions
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// and selects the best encoder given those conditions.
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class EncoderSelectorInterface {
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public:
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virtual ~EncoderSelectorInterface() {}
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// Informs the encoder selector about which encoder that is currently being
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// used.
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virtual void OnCurrentEncoder(const SdpVideoFormat& format) = 0;
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// Called every time the available bitrate is updated. Should return a
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// non-empty if an encoder switch should be performed.
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virtual absl::optional<SdpVideoFormat> OnAvailableBitrate(
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const DataRate& rate) = 0;
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// Called if the currently used encoder reports itself as broken. Should
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// return a non-empty if an encoder switch should be performed.
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virtual absl::optional<SdpVideoFormat> OnEncoderBroken() = 0;
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};
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// Returns a list of supported video formats in order of preference, to use
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// for signaling etc.
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virtual std::vector<SdpVideoFormat> GetSupportedFormats() const = 0;
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// Returns a list of supported video formats in order of preference, that can
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// also be tagged with additional information to allow the VideoEncoderFactory
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// to separate between different implementations when CreateVideoEncoder is
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// called.
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virtual std::vector<SdpVideoFormat> GetImplementations() const {
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return GetSupportedFormats();
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}
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// Returns information about how this format will be encoded. The specified
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// format must be one of the supported formats by this factory.
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// TODO(magjed): Try to get rid of this method. Since is_hardware_accelerated
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// is unused, only factories producing internal source encoders (in itself a
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// deprecated feature) needs to override this method.
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virtual CodecInfo QueryVideoEncoder(const SdpVideoFormat& format) const {
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return CodecInfo();
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}
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// Query whether the specifed format is supported or not and if it will be
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// power efficient, which is currently interpreted as if there is support for
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// hardware acceleration.
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// See https://w3c.github.io/webrtc-svc/#scalabilitymodes* for a specification
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// of valid values for `scalability_mode`.
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// NOTE: QueryCodecSupport is currently an experimental feature that is
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// subject to change without notice.
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virtual CodecSupport QueryCodecSupport(
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const SdpVideoFormat& format,
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absl::optional<std::string> scalability_mode) const {
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// Default implementation, query for supported formats and check if the
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// specified format is supported. Returns false if scalability_mode is
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// specified.
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CodecSupport codec_support;
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if (!scalability_mode) {
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codec_support.is_supported = format.IsCodecInList(GetSupportedFormats());
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}
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return codec_support;
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}
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// Creates a VideoEncoder for the specified format.
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virtual std::unique_ptr<VideoEncoder> CreateVideoEncoder(
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const SdpVideoFormat& format) = 0;
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virtual std::unique_ptr<EncoderSelectorInterface> GetEncoderSelector() const {
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return nullptr;
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}
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virtual ~VideoEncoderFactory() {}
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};
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} // namespace webrtc
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#endif // API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_
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