MediaPuller.cpp revision e1957358f11031a554c57d4fb46988dd6044acc1 
1/*
2 * Copyright 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 "MediaPuller"
19#include <utils/Log.h>
20
21#include "MediaPuller.h"
22
23#include <media/stagefright/foundation/ABuffer.h>
24#include <media/stagefright/foundation/ADebug.h>
25#include <media/stagefright/foundation/AMessage.h>
26#include <media/stagefright/MediaBuffer.h>
27#include <media/stagefright/MediaSource.h>
28#include <media/stagefright/MetaData.h>
29
30namespace android {
31
32MediaPuller::MediaPuller(
33        const sp<MediaSource> &source, const sp<AMessage> &notify)
34    : mSource(source),
35      mNotify(notify),
36      mPullGeneration(0) {
37}
38
39MediaPuller::~MediaPuller() {
40}
41
42status_t MediaPuller::postSynchronouslyAndReturnError(
43        const sp<AMessage> &msg) {
44    sp<AMessage> response;
45    status_t err = msg->postAndAwaitResponse(&response);
46
47    if (err != OK) {
48        return err;
49    }
50
51    if (!response->findInt32("err", &err)) {
52        err = OK;
53    }
54
55    return err;
56}
57
58status_t MediaPuller::start() {
59    return postSynchronouslyAndReturnError(new AMessage(kWhatStart, id()));
60}
61
62status_t MediaPuller::stop() {
63    return postSynchronouslyAndReturnError(new AMessage(kWhatStop, id()));
64}
65
66void MediaPuller::onMessageReceived(const sp<AMessage> &msg) {
67    switch (msg->what()) {
68        case kWhatStart:
69        case kWhatStop:
70        {
71            status_t err;
72
73            if (msg->what() == kWhatStart) {
74                err = mSource->start();
75
76                if (err == OK) {
77                    schedulePull();
78                }
79            } else {
80                err = mSource->stop();
81                ++mPullGeneration;
82            }
83
84            sp<AMessage> response = new AMessage;
85            response->setInt32("err", err);
86
87            uint32_t replyID;
88            CHECK(msg->senderAwaitsResponse(&replyID));
89
90            response->postReply(replyID);
91            break;
92        }
93
94        case kWhatPull:
95        {
96            int32_t generation;
97            CHECK(msg->findInt32("generation", &generation));
98
99            if (generation != mPullGeneration) {
100                break;
101            }
102
103            MediaBuffer *mbuf;
104            status_t err = mSource->read(&mbuf);
105
106            if (err != OK) {
107                if (err == ERROR_END_OF_STREAM) {
108                    ALOGI("stream ended.");
109                } else {
110                    ALOGE("error %d reading stream.", err);
111                }
112
113                sp<AMessage> notify = mNotify->dup();
114                notify->setInt32("what", kWhatEOS);
115                notify->post();
116            } else {
117                int64_t timeUs;
118                CHECK(mbuf->meta_data()->findInt64(kKeyTime, &timeUs));
119
120                sp<ABuffer> accessUnit = new ABuffer(mbuf->range_length());
121
122                memcpy(accessUnit->data(),
123                       (const uint8_t *)mbuf->data() + mbuf->range_offset(),
124                       mbuf->range_length());
125
126                accessUnit->meta()->setInt64("timeUs", timeUs);
127                accessUnit->meta()->setPointer("mediaBuffer", mbuf);
128
129                sp<AMessage> notify = mNotify->dup();
130
131                notify->setInt32("what", kWhatAccessUnit);
132                notify->setBuffer("accessUnit", accessUnit);
133                notify->post();
134
135                schedulePull();
136            }
137            break;
138        }
139
140        default:
141            TRESPASS();
142    }
143}
144
145void MediaPuller::schedulePull() {
146    sp<AMessage> msg = new AMessage(kWhatPull, id());
147    msg->setInt32("generation", mPullGeneration);
148    msg->post();
149}
150
151}  // namespace android
152
153