| // Copyright 2020 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SRC_MEDIA_AUDIO_AUDIO_CORE_TAP_STAGE_H_ |
| #define SRC_MEDIA_AUDIO_AUDIO_CORE_TAP_STAGE_H_ |
| |
| #include <memory> |
| |
| #include "src/media/audio/audio_core/audio_clock.h" |
| #include "src/media/audio/audio_core/mixer/output_producer.h" |
| #include "src/media/audio/audio_core/stream.h" |
| |
| namespace media::audio { |
| |
| // A |TapStage| reads stream buffers from an input |ReadableStream| and copies them to a secondary |
| // |WritableStream|. |
| class TapStage : public ReadableStream { |
| public: |
| // Creates a |TapStage| that returns buffers from |input| while copying their contents into |tap|. |
| TapStage(std::shared_ptr<ReadableStream> input, std::shared_ptr<WritableStream> tap); |
| |
| // |media::audio::ReadableStream| |
| TimelineFunctionSnapshot ref_time_to_frac_presentation_frame() const override { |
| return source_->ref_time_to_frac_presentation_frame(); |
| } |
| AudioClock& reference_clock() override { return source_->reference_clock(); } |
| std::optional<ReadableStream::Buffer> ReadLock(Fixed dest_frame, int64_t frame_count) override; |
| void Trim(Fixed dest_frame) override { source_->Trim(dest_frame); } |
| |
| void SetPresentationDelay(zx::duration external_delay) override; |
| |
| private: |
| std::optional<WritableStream::Buffer> WriteSilenceToTap(int64_t frame, int64_t frame_count); |
| void CopyFrames(std::optional<WritableStream::Buffer> write_buffer, |
| const ReadableStream::Buffer& source, |
| const TimelineFunction& source_frac_frame_to_tap_frac_frame); |
| |
| const TimelineFunction& SourceFracFrameToTapFracFrame(); |
| |
| std::shared_ptr<ReadableStream> source_; |
| std::shared_ptr<WritableStream> tap_; |
| std::unique_ptr<OutputProducer> output_producer_; |
| |
| // Track the mapping of source frames to tap frames. |
| TimelineFunction source_frac_frame_to_tap_frac_frame_; |
| uint32_t source_generation_ = kInvalidGenerationId; |
| uint32_t tap_generation_ = kInvalidGenerationId; |
| }; |
| |
| } // namespace media::audio |
| |
| #endif // SRC_MEDIA_AUDIO_AUDIO_CORE_TAP_STAGE_H_ |