1/*
2 * Copyright (C) 2012 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_NDEBUG 0
18#define LOG_TAG "MediaBufferPuller"
19#include <utils/Log.h>
20
21#include <media/stagefright/MediaSource.h>
22#include <media/stagefright/MediaBuffer.h>
23#include <media/stagefright/MediaDefs.h>
24#include "MediaBufferPuller.h"
25
26namespace android {
27
28
29MediaBufferPuller::MediaBufferPuller(const sp<MediaSource>& source)
30    : mSource(source),
31      mAskToStart(false),
32      mAskToStop(false),
33      mAcquireStopped(false),
34      mReleaseStopped(false),
35      mSourceError(OK) {
36
37    androidCreateThread(acquireThreadStart, this);
38    androidCreateThread(releaseThreadStart, this);
39}
40
41MediaBufferPuller::~MediaBufferPuller() {
42    stop();
43}
44
45bool MediaBufferPuller::hasMediaSourceReturnedError() const {
46    Mutex::Autolock autolock(mLock);
47    return ((mSourceError != OK) ? true : false);
48}
49void MediaBufferPuller::start() {
50    Mutex::Autolock autolock(mLock);
51    mAskToStart = true;
52    mAcquireCond.signal();
53    mReleaseCond.signal();
54}
55
56void MediaBufferPuller::stop() {
57    Mutex::Autolock autolock(mLock);
58    mAskToStop = true;
59    mAcquireCond.signal();
60    mReleaseCond.signal();
61    while (!mAcquireStopped || !mReleaseStopped) {
62        mUserCond.wait(mLock);
63    }
64
65    // Release remaining buffers
66    for (size_t i = 0; i < mBuffers.size(); i++) {
67        mBuffers.itemAt(i)->release();
68    }
69
70    for (size_t i = 0; i < mReleaseBuffers.size(); i++) {
71        mReleaseBuffers.itemAt(i)->release();
72    }
73
74    mBuffers.clear();
75    mReleaseBuffers.clear();
76}
77
78MediaBuffer* MediaBufferPuller::getBufferNonBlocking() {
79    Mutex::Autolock autolock(mLock);
80    if (mBuffers.empty()) {
81        return NULL;
82    } else {
83        MediaBuffer* b = mBuffers.itemAt(0);
84        mBuffers.removeAt(0);
85        return b;
86    }
87}
88
89MediaBuffer* MediaBufferPuller::getBufferBlocking() {
90    Mutex::Autolock autolock(mLock);
91    while (mBuffers.empty() && !mAcquireStopped) {
92        mUserCond.wait(mLock);
93    }
94
95    if (mBuffers.empty()) {
96        return NULL;
97    } else {
98        MediaBuffer* b = mBuffers.itemAt(0);
99        mBuffers.removeAt(0);
100        return b;
101    }
102}
103
104void MediaBufferPuller::putBuffer(MediaBuffer* buffer) {
105    Mutex::Autolock autolock(mLock);
106    mReleaseBuffers.push(buffer);
107    mReleaseCond.signal();
108}
109
110int MediaBufferPuller::acquireThreadStart(void* arg) {
111    MediaBufferPuller* self = (MediaBufferPuller*)arg;
112    self->acquireThreadFunc();
113    return 0;
114}
115
116int MediaBufferPuller::releaseThreadStart(void* arg) {
117    MediaBufferPuller* self = (MediaBufferPuller*)arg;
118    self->releaseThreadFunc();
119    return 0;
120}
121
122void MediaBufferPuller::acquireThreadFunc() {
123    mLock.lock();
124
125    // Wait for the start signal
126    while (!mAskToStart && !mAskToStop) {
127        mAcquireCond.wait(mLock);
128    }
129
130    // Loop until we are asked to stop, or there is nothing more to read
131    while (!mAskToStop) {
132        MediaBuffer* pBuffer;
133        mLock.unlock();
134        status_t result = mSource->read(&pBuffer, NULL);
135        mLock.lock();
136        mSourceError = result;
137        if (result != OK) {
138            break;
139        }
140        mBuffers.push(pBuffer);
141        mUserCond.signal();
142    }
143
144    mAcquireStopped = true;
145    mUserCond.signal();
146    mLock.unlock();
147}
148
149void MediaBufferPuller::releaseThreadFunc() {
150    mLock.lock();
151
152    // Wait for the start signal
153    while (!mAskToStart && !mAskToStop) {
154        mReleaseCond.wait(mLock);
155    }
156
157    // Loop until we are asked to stop
158    while (1) {
159        if (mReleaseBuffers.empty()) {
160            if (mAskToStop) {
161                break;
162            } else {
163                mReleaseCond.wait(mLock);
164                continue;
165            }
166        }
167        MediaBuffer* pBuffer = mReleaseBuffers.itemAt(0);
168        mReleaseBuffers.removeAt(0);
169        mLock.unlock();
170        pBuffer->release();
171        mLock.lock();
172    }
173
174    mReleaseStopped = true;
175    mUserCond.signal();
176    mLock.unlock();
177}
178
179};  // namespace android
180