46ea5d7f82
Two audio channels going into the AudioSource::Sink can either be down-mixed to mono or encoded as stereo. This change enables WebRTC users (such as Chromium) to query the number of audio channels actually encoded. That information can in turn be used to tailor the audio processing to the number of channels actually encoded. This change fixes webrtc:8133 from a WebRTC perspective and will be followed up with the necessary Chromium changes. Bug: webrtc:8133 Change-Id: I8e8a08292002919784c05a5aacb21707918809c8 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/197426 Reviewed-by: Per Åhgren <peah@webrtc.org> Reviewed-by: Magnus Flodman <mflodman@webrtc.org> Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org> Cr-Commit-Position: refs/heads/master@{#32836}
59 lines
1.7 KiB
C++
59 lines
1.7 KiB
C++
/*
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* Copyright (c) 2013 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 MEDIA_BASE_AUDIO_SOURCE_H_
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#define MEDIA_BASE_AUDIO_SOURCE_H_
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#include <cstddef>
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#include "absl/types/optional.h"
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namespace cricket {
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// Abstract interface for providing the audio data.
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// TODO(deadbeef): Rename this to AudioSourceInterface, and rename
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// webrtc::AudioSourceInterface to AudioTrackSourceInterface.
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class AudioSource {
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public:
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class Sink {
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public:
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// Callback to receive data from the AudioSource.
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virtual void OnData(
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const void* audio_data,
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int bits_per_sample,
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int sample_rate,
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size_t number_of_channels,
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size_t number_of_frames,
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absl::optional<int64_t> absolute_capture_timestamp_ms) = 0;
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// Called when the AudioSource is going away.
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virtual void OnClose() = 0;
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// Returns the number of channels encoded by the sink. This can be less than
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// the number_of_channels if down-mixing occur. A value of -1 means an
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// unknown number.
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virtual int NumPreferredChannels() const = 0;
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protected:
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virtual ~Sink() {}
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};
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// Sets a sink to the AudioSource. There can be only one sink connected
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// to the source at a time.
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virtual void SetSink(Sink* sink) = 0;
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protected:
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virtual ~AudioSource() {}
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};
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} // namespace cricket
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#endif // MEDIA_BASE_AUDIO_SOURCE_H_
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