SpdifStreamOut.cpp revision 062e67a26e0553dd142be622821f493df541f0c6 
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#define LOG_TAG "AudioFlinger"
19//#define LOG_NDEBUG 0
20#include <hardware/audio.h>
21#include <utils/Log.h>
22
23#include <audio_utils/spdif/SPDIFEncoder.h>
24
25#include "AudioHwDevice.h"
26#include "AudioStreamOut.h"
27#include "SpdifStreamOut.h"
28
29namespace android {
30
31/**
32 * If the AudioFlinger is processing encoded data and the HAL expects
33 * PCM then we need to wrap the data in an SPDIF wrapper.
34 */
35SpdifStreamOut::SpdifStreamOut(AudioHwDevice *dev, audio_output_flags_t flags)
36        : AudioStreamOut(dev,flags)
37        , mRateMultiplier(1)
38        , mSpdifEncoder(this)
39        , mRenderPositionHal(0)
40        , mPreviousHalPosition32(0)
41{
42}
43
44status_t SpdifStreamOut::open(
45                              audio_io_handle_t handle,
46                              audio_devices_t devices,
47                              struct audio_config *config,
48                              const char *address)
49{
50    struct audio_config customConfig = *config;
51
52    customConfig.format = AUDIO_FORMAT_PCM_16_BIT;
53    customConfig.channel_mask = AUDIO_CHANNEL_OUT_STEREO;
54
55    // Some data bursts run at a higher sample rate.
56    switch(config->format) {
57        case AUDIO_FORMAT_E_AC3:
58            mRateMultiplier = 4;
59            break;
60        case AUDIO_FORMAT_AC3:
61            mRateMultiplier = 1;
62            break;
63        default:
64            ALOGE("ERROR SpdifStreamOut::open() unrecognized format 0x%08X\n",
65                config->format);
66            return BAD_VALUE;
67    }
68    customConfig.sample_rate = config->sample_rate * mRateMultiplier;
69
70    // Always print this because otherwise it could be very confusing if the
71    // HAL and AudioFlinger are using different formats.
72    // Print before open() because HAL may modify customConfig.
73    ALOGI("SpdifStreamOut::open() AudioFlinger requested"
74            " sampleRate %d, format %#x, channelMask %#x",
75            config->sample_rate,
76            config->format,
77            config->channel_mask);
78    ALOGI("SpdifStreamOut::open() HAL configured for"
79            " sampleRate %d, format %#x, channelMask %#x",
80            customConfig.sample_rate,
81            customConfig.format,
82            customConfig.channel_mask);
83
84    status_t status = AudioStreamOut::open(
85            handle,
86            devices,
87            &customConfig,
88            address);
89
90    ALOGI("SpdifStreamOut::open() status = %d", status);
91
92    return status;
93}
94
95// Account for possibly higher sample rate.
96status_t SpdifStreamOut::getRenderPosition(uint32_t *frames)
97{
98    uint32_t halPosition = 0;
99    status_t status = AudioStreamOut::getRenderPosition(&halPosition);
100    if (status != NO_ERROR) {
101        return status;
102    }
103
104    // Accumulate a 64-bit position so that we wrap at the right place.
105    if (mRateMultiplier != 1) {
106        // Maintain a 64-bit render position.
107        int32_t deltaHalPosition = (int32_t)(halPosition - mPreviousHalPosition32);
108        mPreviousHalPosition32 = halPosition;
109        mRenderPositionHal += deltaHalPosition;
110
111        // Scale from device sample rate to application rate.
112        uint64_t renderPositionApp = mRenderPositionHal / mRateMultiplier;
113        ALOGV("SpdifStreamOut::getRenderPosition() "
114            "renderPositionAppRate = %llu = %llu / %u\n",
115            renderPositionApp, mRenderPositionHal, mRateMultiplier);
116
117        *frames = (uint32_t)renderPositionApp;
118    } else {
119        *frames = halPosition;
120    }
121    return status;
122}
123
124int SpdifStreamOut::flush()
125{
126    // FIXME Is there an issue here with flush being asynchronous?
127    mRenderPositionHal = 0;
128    mPreviousHalPosition32 = 0;
129    return AudioStreamOut::flush();
130}
131
132int SpdifStreamOut::standby()
133{
134    mRenderPositionHal = 0;
135    mPreviousHalPosition32 = 0;
136    return AudioStreamOut::standby();
137}
138
139// Account for possibly higher sample rate.
140// This is much easier when all the values are 64-bit.
141status_t SpdifStreamOut::getPresentationPosition(uint64_t *frames,
142        struct timespec *timestamp)
143{
144    uint64_t halFrames = 0;
145    status_t status = AudioStreamOut::getPresentationPosition(&halFrames, timestamp);
146    *frames = halFrames / mRateMultiplier;
147    return status;
148}
149
150size_t SpdifStreamOut::getFrameSize()
151{
152    return sizeof(int8_t);
153}
154
155ssize_t SpdifStreamOut::writeDataBurst(const void* buffer, size_t bytes)
156{
157    return AudioStreamOut::write(buffer, bytes);
158}
159
160ssize_t SpdifStreamOut::write(const void* buffer, size_t bytes)
161{
162    // Write to SPDIF wrapper. It will call back to writeDataBurst().
163    return mSpdifEncoder.write(buffer, bytes);
164}
165
166} // namespace android
167