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/*
**
** Copyright 2015, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#ifndef ANDROID_AUDIO_STREAM_OUT_H
#define ANDROID_AUDIO_STREAM_OUT_H
#include <stdint.h>
#include <sys/types.h>
#include <system/audio.h>
#include "AudioStreamOut.h"
namespace android {
class AudioHwDevice;
/**
* Managed access to a HAL output stream.
*/
class AudioStreamOut {
public:
// AudioStreamOut is immutable, so its fields are const.
// For emphasis, we could also make all pointers to them be "const *",
// but that would clutter the code unnecessarily.
AudioHwDevice * const audioHwDev;
audio_stream_out_t *stream;
const audio_output_flags_t flags;
audio_hw_device_t *hwDev() const;
AudioStreamOut(AudioHwDevice *dev, audio_output_flags_t flags);
virtual status_t open(
audio_io_handle_t handle,
audio_devices_t devices,
struct audio_config *config,
const char *address);
virtual ~AudioStreamOut() { }
// Get the bottom 32-bits of the 64-bit render position.
status_t getRenderPosition(uint32_t *frames);
virtual status_t getRenderPosition(uint64_t *frames);
virtual status_t getPresentationPosition(uint64_t *frames, struct timespec *timestamp);
/**
* Write audio buffer to driver. Returns number of bytes written, or a
* negative status_t. If at least one frame was written successfully prior to the error,
* it is suggested that the driver return that successful (short) byte count
* and then return an error in the subsequent call.
*
* If set_callback() has previously been called to enable non-blocking mode
* the write() is not allowed to block. It must write only the number of
* bytes that currently fit in the driver/hardware buffer and then return
* this byte count. If this is less than the requested write size the
* callback function must be called when more space is available in the
* driver/hardware buffer.
*/
virtual ssize_t write(const void *buffer, size_t bytes);
/**
* @return frame size from the perspective of the application and the AudioFlinger.
*/
virtual size_t getFrameSize() const { return mHalFrameSize; }
/**
* @return format from the perspective of the application and the AudioFlinger.
*/
virtual audio_format_t getFormat() const;
/**
* The HAL may be running at a higher sample rate if, for example, playing wrapped EAC3.
* @return sample rate from the perspective of the application and the AudioFlinger.
*/
virtual uint32_t getSampleRate() const;
/**
* The HAL is in stereo mode when playing multi-channel compressed audio over HDMI.
* @return channel mask from the perspective of the application and the AudioFlinger.
*/
virtual audio_channel_mask_t getChannelMask() const;
virtual status_t flush();
virtual status_t standby();
protected:
uint64_t mFramesWritten; // reset by flush
uint64_t mFramesWrittenAtStandby;
uint64_t mRenderPosition; // reset by flush or standby
int mRateMultiplier;
bool mHalFormatIsLinearPcm;
size_t mHalFrameSize;
};
} // namespace android
#endif // ANDROID_AUDIO_STREAM_OUT_H
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