TimedTextPlayer.cpp revision f1d5aa162c02a16b7195a43a9bcea4d592600ac4 
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 "TimedTextPlayer"
19#include <utils/Log.h>
20
21#include <media/stagefright/foundation/ADebug.h>
22#include <media/stagefright/foundation/AMessage.h>
23#include <media/stagefright/MediaErrors.h>
24#include <media/MediaPlayerInterface.h>
25
26#include "TimedTextPlayer.h"
27
28#include "TimedTextDriver.h"
29#include "TimedTextSource.h"
30
31namespace android {
32
33static const int64_t kAdjustmentProcessingTimeUs = 100000ll;
34
35TimedTextPlayer::TimedTextPlayer(const wp<MediaPlayerBase> &listener)
36    : mListener(listener),
37      mSource(NULL),
38      mSendSubtitleGeneration(0) {
39}
40
41TimedTextPlayer::~TimedTextPlayer() {
42    if (mSource != NULL) {
43        mSource->stop();
44        mSource.clear();
45        mSource = NULL;
46    }
47}
48
49void TimedTextPlayer::start() {
50    sp<AMessage> msg = new AMessage(kWhatSeek, id());
51    msg->setInt64("seekTimeUs", -1);
52    msg->post();
53}
54
55void TimedTextPlayer::pause() {
56    (new AMessage(kWhatPause, id()))->post();
57}
58
59void TimedTextPlayer::resume() {
60    start();
61}
62
63void TimedTextPlayer::seekToAsync(int64_t timeUs) {
64    sp<AMessage> msg = new AMessage(kWhatSeek, id());
65    msg->setInt64("seekTimeUs", timeUs);
66    msg->post();
67}
68
69void TimedTextPlayer::setDataSource(sp<TimedTextSource> source) {
70    sp<AMessage> msg = new AMessage(kWhatSetSource, id());
71    msg->setObject("source", source);
72    msg->post();
73}
74
75void TimedTextPlayer::onMessageReceived(const sp<AMessage> &msg) {
76    switch (msg->what()) {
77        case kWhatPause: {
78            mSendSubtitleGeneration++;
79            break;
80        }
81        case kWhatSeek: {
82            int64_t seekTimeUs = 0;
83            msg->findInt64("seekTimeUs", &seekTimeUs);
84            if (seekTimeUs < 0) {
85                sp<MediaPlayerBase> listener = mListener.promote();
86                if (listener != NULL) {
87                    int32_t positionMs = 0;
88                    listener->getCurrentPosition(&positionMs);
89                    seekTimeUs = positionMs * 1000ll;
90                }
91            }
92            doSeekAndRead(seekTimeUs);
93            break;
94        }
95        case kWhatSendSubtitle: {
96            int32_t generation;
97            CHECK(msg->findInt32("generation", &generation));
98            if (generation != mSendSubtitleGeneration) {
99              // Drop obsolete msg.
100              break;
101            }
102            sp<RefBase> obj;
103            msg->findObject("subtitle", &obj);
104            if (obj != NULL) {
105                sp<ParcelEvent> parcelEvent;
106                parcelEvent = static_cast<ParcelEvent*>(obj.get());
107                notifyListener(MEDIA_TIMED_TEXT, &(parcelEvent->parcel));
108            } else {
109                notifyListener(MEDIA_TIMED_TEXT);
110            }
111            doRead();
112            break;
113        }
114        case kWhatSetSource: {
115            sp<RefBase> obj;
116            msg->findObject("source", &obj);
117            if (obj == NULL) break;
118            if (mSource != NULL) {
119                mSource->stop();
120            }
121            mSource = static_cast<TimedTextSource*>(obj.get());
122            mSource->start();
123            Parcel parcel;
124            if (mSource->extractGlobalDescriptions(&parcel) == OK &&
125                parcel.dataSize() > 0) {
126                notifyListener(MEDIA_TIMED_TEXT, &parcel);
127            } else {
128                notifyListener(MEDIA_TIMED_TEXT);
129            }
130            break;
131        }
132    }
133}
134
135void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
136    MediaSource::ReadOptions options;
137    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
138    doRead(&options);
139}
140
141void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
142    int64_t timeUs = 0;
143    sp<ParcelEvent> parcelEvent = new ParcelEvent();
144    mSource->read(&timeUs, &(parcelEvent->parcel), options);
145    postTextEvent(parcelEvent, timeUs);
146}
147
148void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
149    sp<MediaPlayerBase> listener = mListener.promote();
150    if (listener != NULL) {
151        int64_t positionUs, delayUs;
152        int32_t positionMs = 0;
153        listener->getCurrentPosition(&positionMs);
154        positionUs = positionMs * 1000;
155
156        if (timeUs <= positionUs + kAdjustmentProcessingTimeUs) {
157            delayUs = 0;
158        } else {
159            delayUs = timeUs - positionUs - kAdjustmentProcessingTimeUs;
160        }
161        sp<AMessage> msg = new AMessage(kWhatSendSubtitle, id());
162        msg->setInt32("generation", mSendSubtitleGeneration);
163        if (parcel != NULL) {
164            msg->setObject("subtitle", parcel);
165        }
166        msg->post(delayUs);
167    }
168}
169
170void TimedTextPlayer::notifyListener(int msg, const Parcel *parcel) {
171    sp<MediaPlayerBase> listener = mListener.promote();
172    if (listener != NULL) {
173        if (parcel != NULL && (parcel->dataSize() > 0)) {
174            listener->sendEvent(msg, 0, 0, parcel);
175        } else {  // send an empty timed text to clear the screen
176            listener->sendEvent(msg);
177        }
178    }
179}
180
181}  // namespace android
182