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
32namespace 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 */
38class SpdifStreamOut : public AudioStreamOut {
39public:
40
41    SpdifStreamOut(AudioHwDevice *dev, audio_output_flags_t flags,
42            audio_format_t format);
43
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     */
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     */
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     */
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     */
87    virtual audio_channel_mask_t getChannelMask() const { return mApplicationChannelMask; }
88
89    virtual status_t flush();
90    virtual status_t standby();
91
92private:
93
94    class MySPDIFEncoder : public SPDIFEncoder
95    {
96    public:
97        MySPDIFEncoder(SpdifStreamOut *spdifStreamOut, audio_format_t format)
98          :  SPDIFEncoder(format)
99          , mSpdifStreamOut(spdifStreamOut)
100        {
101        }
102
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