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media / audio / audio_handler.h [blame]
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_AUDIO_AUDIO_HANDLER_H_
#define MEDIA_AUDIO_AUDIO_HANDLER_H_
#include "base/time/time.h"
#include "media/base/media_export.h"
namespace media {
class AudioBus;
// The implementations of the class are expected to return the decoded audio
// data in order starting from the beginning of the stream via `CopyTo()` until
// reaching the end of the stream.
class MEDIA_EXPORT AudioHandler {
public:
AudioHandler() = default;
AudioHandler(const AudioHandler&) = delete;
AudioHandler& operator=(const AudioHandler&) = delete;
virtual ~AudioHandler() = default;
// The number of frames of `bus` in `CopyTo()`.
static constexpr int kDefaultFrameCount = 1024;
// Returns true if the instance of this class can be initialized successfully.
virtual bool Initialize() = 0;
virtual int GetNumChannels() const = 0;
virtual int GetSampleRate() const = 0;
virtual base::TimeDelta GetDuration() const = 0;
// Returns true once `CopyTo()` has reached end of stream.
virtual bool AtEnd() const = 0;
// Fills `bus` with available audio data. If bus can't be completely filled,
// this will be reflected in `frames_written`.
// Notes that this is a stateful function and each call to it will resume
// where the previous `CopyTo()` stops.
virtual bool CopyTo(AudioBus* bus, size_t* frames_written) = 0;
// Restores initial state to the head of the stream.
virtual void Reset() = 0;
};
} // namespace media
#endif // MEDIA_AUDIO_AUDIO_HANDLER_H_