1/* 2** 3** Copyright 2015, The Android Open Source Project 4** 5** Licensed under the Apache License, Version 2.0 (the "License"); 6** you may not use this file except in compliance with the License. 7** You may obtain a copy of the License at 8** 9** http://www.apache.org/licenses/LICENSE-2.0 10** 11** Unless required by applicable law or agreed to in writing, software 12** distributed under the License is distributed on an "AS IS" BASIS, 13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14** See the License for the specific language governing permissions and 15** limitations under the License. 16*/ 17 18#ifndef ANDROID_SPDIF_STREAM_OUT_H 19#define ANDROID_SPDIF_STREAM_OUT_H 20 21#include <stdint.h> 22#include <sys/types.h> 23 24#include <system/audio.h> 25 26#include "AudioStreamOut.h" 27 28#include <audio_utils/spdif/SPDIFEncoder.h> 29 30namespace android { 31 32/** 33 * Stream that is a PCM data burst in the HAL but looks like an encoded stream 34 * to the AudioFlinger. Wraps encoded data in an SPDIF wrapper per IEC61973-3. 35 */ 36class SpdifStreamOut : public AudioStreamOut { 37public: 38 39 SpdifStreamOut(AudioHwDevice *dev, audio_output_flags_t flags, 40 audio_format_t format); 41 42 virtual ~SpdifStreamOut() { } 43 44 virtual status_t open( 45 audio_io_handle_t handle, 46 audio_devices_t devices, 47 struct audio_config *config, 48 const char *address); 49 50 /** 51 * Write audio buffer to driver. Returns number of bytes written, or a 52 * negative status_t. If at least one frame was written successfully prior to the error, 53 * it is suggested that the driver return that successful (short) byte count 54 * and then return an error in the subsequent call. 55 * 56 * If set_callback() has previously been called to enable non-blocking mode 57 * the write() is not allowed to block. It must write only the number of 58 * bytes that currently fit in the driver/hardware buffer and then return 59 * this byte count. If this is less than the requested write size the 60 * callback function must be called when more space is available in the 61 * driver/hardware buffer. 62 */ 63 virtual ssize_t write(const void* buffer, size_t bytes); 64 65 /** 66 * @return frame size from the perspective of the application and the AudioFlinger. 67 */ 68 virtual size_t getFrameSize() const { return sizeof(int8_t); } 69 70 /** 71 * @return format from the perspective of the application and the AudioFlinger. 72 */ 73 virtual audio_format_t getFormat() const { return mApplicationFormat; } 74 75 /** 76 * The HAL may be running at a higher sample rate if, for example, playing wrapped EAC3. 77 * @return sample rate from the perspective of the application and the AudioFlinger. 78 */ 79 virtual uint32_t getSampleRate() const { return mApplicationSampleRate; } 80 81 /** 82 * The HAL is in stereo mode when playing multi-channel compressed audio over HDMI. 83 * @return channel mask from the perspective of the application and the AudioFlinger. 84 */ 85 virtual audio_channel_mask_t getChannelMask() const { return mApplicationChannelMask; } 86 87 virtual status_t flush(); 88 virtual status_t standby(); 89 90private: 91 92 class MySPDIFEncoder : public SPDIFEncoder 93 { 94 public: 95 MySPDIFEncoder(SpdifStreamOut *spdifStreamOut, audio_format_t format) 96 : SPDIFEncoder(format) 97 , mSpdifStreamOut(spdifStreamOut) 98 { 99 } 100 101 virtual ssize_t writeOutput(const void* buffer, size_t bytes) 102 { 103 return mSpdifStreamOut->writeDataBurst(buffer, bytes); 104 } 105 protected: 106 SpdifStreamOut * const mSpdifStreamOut; 107 }; 108 109 MySPDIFEncoder mSpdifEncoder; 110 audio_format_t mApplicationFormat; 111 uint32_t mApplicationSampleRate; 112 audio_channel_mask_t mApplicationChannelMask; 113 114 ssize_t writeDataBurst(const void* data, size_t bytes); 115 ssize_t writeInternal(const void* buffer, size_t bytes); 116 117}; 118 119} // namespace android 120 121#endif // ANDROID_SPDIF_STREAM_OUT_H 122