blob: 5043b8583444ef0b9fa7d86349dc05742d7bc361 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <vector>
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "media/audio/audio_parameters.h"
#include "media/base/audio_bus.h"
#include "media/base/media_export.h"
#if defined(OS_STARBOARD)
#include "starboard/configuration.h"
#endif // defined(OS_STARBOARD)
namespace media {
// AudioRendererSink is an interface representing the end-point for
// rendered audio. An implementation is expected to
// periodically call Render() on a callback object.
class MEDIA_EXPORT AudioRendererSink
: public base::RefCountedThreadSafe<media::AudioRendererSink> {
class MEDIA_EXPORT RenderCallback {
// Attempts to completely fill all channels of |dest|, returns actual
// number of frames filled.
virtual int Render(AudioBus* dest, int audio_delay_milliseconds) = 0;
// Synchronized audio I/O - see InitializeIO() below.
virtual void RenderIO(AudioBus* /* source */,
AudioBus* /* dest */,
int /* audio_delay_milliseconds */) {}
// Signals an error has occurred.
virtual void OnRenderError() = 0;
#if defined(__LB_SHELL__) || defined(COBALT)
// Callback from the sink to the renderer to indicate that it is currently
// full and will not be requesting additional data until some is consumed.
virtual void SinkFull() = 0;
#if defined(OS_STARBOARD)
// Callback from the sink to the renderer to indicate that it has not
// enough data to continue playback without playing past the end of
// buffered data.
virtual void SinkUnderflow() = 0;
#endif // defined(OS_STARBOARD)
#endif // defined(__LB_SHELL__) || defined(COBALT)
virtual ~RenderCallback() {}
// Sets important information about the audio stream format.
// It must be called before any of the other methods.
virtual void Initialize(const AudioParameters& params,
RenderCallback* callback) = 0;
// InitializeIO() may be called instead of Initialize() for clients who wish
// to have synchronized input and output. |input_channels| specifies the
// number of input channels which will be at the same sample-rate
// and buffer-size as the output as specified in |params|.
// The callback's RenderIO() method will be called instead of Render(),
// providing the synchronized input data at the same time as when new
// output data is to be rendered.
virtual void InitializeIO(const AudioParameters& /* params */,
int /* input_channels */,
RenderCallback* /* callback */) {}
// Starts audio playback.
virtual void Start() = 0;
// Stops audio playback.
virtual void Stop() = 0;
// Pauses playback.
virtual void Pause(bool flush) = 0;
// Resumes playback after calling Pause().
virtual void Play() = 0;
// Sets the playback volume, with range [0.0, 1.0] inclusive.
// Returns |true| on success.
virtual bool SetVolume(double volume) = 0;
#if defined(__LB_SHELL__) || defined(COBALT)
// To avoid duplication of audio data and additional copies our Sink
// implementation is responsible for buffering rendered audio. As a
// result the renderer relays the message to buffer more audio back
// to the Sink.
virtual void ResumeAfterUnderflow(bool buffer_more_audio) = 0;
friend class base::RefCountedThreadSafe<AudioRendererSink>;
virtual ~AudioRendererSink() {}
} // namespace media