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 "AudioHwDevice.h" 27 #include "AudioStreamOut.h" 28 #include "SpdifStreamOut.h" 29 30 #include <audio_utils/spdif/SPDIFEncoder.h> 31 32 namespace android { 33 34 /** 35 * Stream that is a PCM data burst in the HAL but looks like an encoded stream 36 * to the AudioFlinger. Wraps encoded data in an SPDIF wrapper per IEC61973-3. 37 */ 38 class SpdifStreamOut : public AudioStreamOut { 39 public: 40 41 SpdifStreamOut(AudioHwDevice *dev, audio_output_flags_t flags, 42 audio_format_t format); 43 ~SpdifStreamOut()44 virtual ~SpdifStreamOut() { } 45 46 virtual status_t open( 47 audio_io_handle_t handle, 48 audio_devices_t devices, 49 struct audio_config *config, 50 const char *address); 51 52 /** 53 * Write audio buffer to driver. Returns number of bytes written, or a 54 * negative status_t. If at least one frame was written successfully prior to the error, 55 * it is suggested that the driver return that successful (short) byte count 56 * and then return an error in the subsequent call. 57 * 58 * If set_callback() has previously been called to enable non-blocking mode 59 * the write() is not allowed to block. It must write only the number of 60 * bytes that currently fit in the driver/hardware buffer and then return 61 * this byte count. If this is less than the requested write size the 62 * callback function must be called when more space is available in the 63 * driver/hardware buffer. 64 */ 65 virtual ssize_t write(const void* buffer, size_t bytes); 66 67 /** 68 * @return frame size from the perspective of the application and the AudioFlinger. 69 */ getFrameSize()70 virtual size_t getFrameSize() const { return sizeof(int8_t); } 71 72 /** 73 * @return format from the perspective of the application and the AudioFlinger. 74 */ getFormat()75 virtual audio_format_t getFormat() const { return mApplicationFormat; } 76 77 /** 78 * The HAL may be running at a higher sample rate if, for example, playing wrapped EAC3. 79 * @return sample rate from the perspective of the application and the AudioFlinger. 80 */ getSampleRate()81 virtual uint32_t getSampleRate() const { return mApplicationSampleRate; } 82 83 /** 84 * The HAL is in stereo mode when playing multi-channel compressed audio over HDMI. 85 * @return channel mask from the perspective of the application and the AudioFlinger. 86 */ getChannelMask()87 virtual audio_channel_mask_t getChannelMask() const { return mApplicationChannelMask; } 88 89 virtual status_t flush(); 90 virtual status_t standby(); 91 92 private: 93 94 class MySPDIFEncoder : public SPDIFEncoder 95 { 96 public: MySPDIFEncoder(SpdifStreamOut * spdifStreamOut,audio_format_t format)97 MySPDIFEncoder(SpdifStreamOut *spdifStreamOut, audio_format_t format) 98 : SPDIFEncoder(format) 99 , mSpdifStreamOut(spdifStreamOut) 100 { 101 } 102 writeOutput(const void * buffer,size_t bytes)103 virtual ssize_t writeOutput(const void* buffer, size_t bytes) 104 { 105 return mSpdifStreamOut->writeDataBurst(buffer, bytes); 106 } 107 protected: 108 SpdifStreamOut * const mSpdifStreamOut; 109 }; 110 111 MySPDIFEncoder mSpdifEncoder; 112 audio_format_t mApplicationFormat; 113 uint32_t mApplicationSampleRate; 114 audio_channel_mask_t mApplicationChannelMask; 115 116 ssize_t writeDataBurst(const void* data, size_t bytes); 117 ssize_t writeInternal(const void* buffer, size_t bytes); 118 119 }; 120 121 } // namespace android 122 123 #endif // ANDROID_SPDIF_STREAM_OUT_H 124