AAudioServiceEndpointPlay.cpp revision 87c9f646a94259d7c321c3b3d5947fa1778f5ac2 
1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "AAudioService"
18//#define LOG_NDEBUG 0
19#include <utils/Log.h>
20
21#include <assert.h>
22#include <map>
23#include <mutex>
24#include <utils/Singleton.h>
25
26#include "AAudioEndpointManager.h"
27#include "AAudioServiceEndpoint.h"
28#include <algorithm>
29#include <mutex>
30#include <vector>
31
32#include "core/AudioStreamBuilder.h"
33#include "AAudioServiceEndpoint.h"
34#include "AAudioServiceStreamShared.h"
35#include "AAudioServiceEndpointPlay.h"
36
37using namespace android;  // TODO just import names needed
38using namespace aaudio;   // TODO just import names needed
39
40#define BURSTS_PER_BUFFER_DEFAULT   2
41
42AAudioServiceEndpointPlay::AAudioServiceEndpointPlay(AAudioService &audioService)
43        : mStreamInternalPlay(audioService, true) {
44}
45
46AAudioServiceEndpointPlay::~AAudioServiceEndpointPlay() {
47}
48
49aaudio_result_t AAudioServiceEndpointPlay::open(int32_t deviceId) {
50    aaudio_result_t result = AAudioServiceEndpoint::open(deviceId);
51    if (result == AAUDIO_OK) {
52        mMixer.allocate(getStreamInternal()->getSamplesPerFrame(),
53                        getStreamInternal()->getFramesPerBurst());
54
55        int32_t burstsPerBuffer = AAudioProperty_getMixerBursts();
56        if (burstsPerBuffer == 0) {
57            mLatencyTuningEnabled = true;
58            burstsPerBuffer = BURSTS_PER_BUFFER_DEFAULT;
59        }
60        ALOGD("AAudioServiceEndpoint(): burstsPerBuffer = %d", burstsPerBuffer);
61        int32_t desiredBufferSize = burstsPerBuffer * getStreamInternal()->getFramesPerBurst();
62        getStreamInternal()->setBufferSize(desiredBufferSize);
63    }
64    return result;
65}
66
67// Mix data from each application stream and write result to the shared MMAP stream.
68void *AAudioServiceEndpointPlay::callbackLoop() {
69    ALOGD("AAudioServiceEndpointPlay(): callbackLoop() entering");
70    int32_t underflowCount = 0;
71
72    aaudio_result_t result = getStreamInternal()->requestStart();
73
74    int64_t timeoutNanos = getStreamInternal()->calculateReasonableTimeout();
75
76    // result might be a frame count
77    while (mCallbackEnabled.load() && getStreamInternal()->isActive() && (result >= 0)) {
78        // Mix data from each active stream.
79        mMixer.clear();
80        { // use lock guard
81            std::lock_guard <std::mutex> lock(mLockStreams);
82            for (AAudioServiceStreamShared *sharedStream : mRunningStreams) {
83                FifoBuffer *fifo = sharedStream->getDataFifoBuffer();
84                float volume = 0.5; // TODO get from system
85                bool underflowed = mMixer.mix(fifo, volume);
86                underflowCount += underflowed ? 1 : 0;
87                // TODO log underflows in each stream
88                sharedStream->markTransferTime(AudioClock::getNanoseconds());
89            }
90        }
91
92        // Write mixer output to stream using a blocking write.
93        result = getStreamInternal()->write(mMixer.getOutputBuffer(),
94                                            getFramesPerBurst(), timeoutNanos);
95        if (result == AAUDIO_ERROR_DISCONNECTED) {
96            disconnectRegisteredStreams();
97            break;
98        } else if (result != getFramesPerBurst()) {
99            ALOGW("AAudioServiceEndpoint(): callbackLoop() wrote %d / %d",
100                  result, getFramesPerBurst());
101            break;
102        }
103    }
104
105    result = getStreamInternal()->requestStop();
106
107    ALOGD("AAudioServiceEndpointPlay(): callbackLoop() exiting, %d underflows", underflowCount);
108    return NULL; // TODO review
109}
110