TimedTextPlayer.cpp revision 2f0632f12cd02b0350918720443c888b48f4417b 
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 <limits.h>
22#include <media/stagefright/foundation/ADebug.h>
23#include <media/stagefright/foundation/AMessage.h>
24#include <media/stagefright/timedtext/TimedTextDriver.h>
25#include <media/stagefright/MediaErrors.h>
26#include <media/MediaPlayerInterface.h>
27
28#include "TimedTextPlayer.h"
29
30#include "TimedTextSource.h"
31
32namespace android {
33
34// Event should be fired a bit earlier considering the processing time till
35// application actually gets the notification message.
36static const int64_t kAdjustmentProcessingTimeUs = 100000ll;
37static const int64_t kMaxDelayUs = 5000000ll;
38static const int64_t kWaitTimeUsToRetryRead = 100000ll;
39static const int64_t kInvalidTimeUs = INT_MIN;
40
41TimedTextPlayer::TimedTextPlayer(const wp<MediaPlayerBase> &listener)
42    : mListener(listener),
43      mSource(NULL),
44      mSendSubtitleGeneration(0) {
45}
46
47TimedTextPlayer::~TimedTextPlayer() {
48    if (mSource != NULL) {
49        mSource->stop();
50        mSource.clear();
51        mSource = NULL;
52    }
53}
54
55void TimedTextPlayer::start() {
56    sp<AMessage> msg = new AMessage(kWhatSeek, id());
57    msg->setInt64("seekTimeUs", -1);
58    msg->post();
59}
60
61void TimedTextPlayer::pause() {
62    (new AMessage(kWhatPause, id()))->post();
63}
64
65void TimedTextPlayer::seekToAsync(int64_t timeUs) {
66    sp<AMessage> msg = new AMessage(kWhatSeek, id());
67    msg->setInt64("seekTimeUs", timeUs);
68    msg->post();
69}
70
71void TimedTextPlayer::setDataSource(sp<TimedTextSource> source) {
72    sp<AMessage> msg = new AMessage(kWhatSetSource, id());
73    msg->setObject("source", source);
74    msg->post();
75}
76
77void TimedTextPlayer::onMessageReceived(const sp<AMessage> &msg) {
78    switch (msg->what()) {
79        case kWhatPause: {
80            mSendSubtitleGeneration++;
81            break;
82        }
83        case kWhatRetryRead: {
84            int64_t seekTimeUs;
85            int seekMode;
86            if (msg->findInt64("seekTimeUs", &seekTimeUs) &&
87                msg->findInt32("seekMode", &seekMode)) {
88                MediaSource::ReadOptions options;
89                options.setSeekTo(
90                    seekTimeUs,
91                    static_cast<MediaSource::ReadOptions::SeekMode>(seekMode));
92                doRead(&options);
93            } else {
94                doRead();
95            }
96            break;
97        }
98        case kWhatSeek: {
99            int64_t seekTimeUs = 0;
100            msg->findInt64("seekTimeUs", &seekTimeUs);
101            if (seekTimeUs < 0) {
102                sp<MediaPlayerBase> listener = mListener.promote();
103                if (listener != NULL) {
104                    int32_t positionMs = 0;
105                    listener->getCurrentPosition(&positionMs);
106                    seekTimeUs = positionMs * 1000ll;
107                }
108            }
109            doSeekAndRead(seekTimeUs);
110            break;
111        }
112        case kWhatSendSubtitle: {
113            int32_t generation;
114            CHECK(msg->findInt32("generation", &generation));
115            if (generation != mSendSubtitleGeneration) {
116              // Drop obsolete msg.
117              break;
118            }
119            // If current time doesn't reach to the fire time,
120            // re-post the message with the adjusted delay time.
121            int64_t fireTimeUs = kInvalidTimeUs;
122            if (msg->findInt64("fireTimeUs", &fireTimeUs)) {
123                // TODO: check if fireTimeUs is not kInvalidTimeUs.
124                int64_t delayUs = delayUsFromCurrentTime(fireTimeUs);
125                if (delayUs > 0) {
126                    msg->post(delayUs);
127                    break;
128                }
129            }
130            sp<RefBase> obj;
131            if (msg->findObject("subtitle", &obj)) {
132                sp<ParcelEvent> parcelEvent;
133                parcelEvent = static_cast<ParcelEvent*>(obj.get());
134                notifyListener(&(parcelEvent->parcel));
135                doRead();
136            } else {
137                notifyListener();
138            }
139            break;
140        }
141        case kWhatSetSource: {
142            sp<RefBase> obj;
143            msg->findObject("source", &obj);
144            if (obj == NULL) break;
145            if (mSource != NULL) {
146                mSource->stop();
147            }
148            mSource = static_cast<TimedTextSource*>(obj.get());
149            status_t err = mSource->start();
150            if (err != OK) {
151                notifyError(err);
152                break;
153            }
154            Parcel parcel;
155            err = mSource->extractGlobalDescriptions(&parcel);
156            if (err != OK) {
157                notifyError(err);
158                break;
159            }
160            notifyListener(&parcel);
161            break;
162        }
163    }
164}
165
166void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
167    MediaSource::ReadOptions options;
168    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
169    doRead(&options);
170}
171
172void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
173    int64_t startTimeUs = 0;
174    int64_t endTimeUs = 0;
175    sp<ParcelEvent> parcelEvent = new ParcelEvent();
176    status_t err = mSource->read(&startTimeUs, &endTimeUs,
177                                 &(parcelEvent->parcel), options);
178    if (err == WOULD_BLOCK) {
179        sp<AMessage> msg = new AMessage(kWhatRetryRead, id());
180        if (options != NULL) {
181            int64_t seekTimeUs;
182            MediaSource::ReadOptions::SeekMode seekMode;
183            CHECK(options->getSeekTo(&seekTimeUs, &seekMode));
184            msg->setInt64("seekTimeUs", seekTimeUs);
185            msg->setInt32("seekMode", seekMode);
186        }
187        msg->post(kWaitTimeUsToRetryRead);
188        return;
189    } else if (err != OK) {
190        notifyError(err);
191        return;
192    }
193
194    postTextEvent(parcelEvent, startTimeUs);
195    if (endTimeUs > 0) {
196        CHECK_GE(endTimeUs, startTimeUs);
197        // send an empty timed text to clear the subtitle when it reaches to the
198        // end time.
199        postTextEvent(NULL, endTimeUs);
200    }
201}
202
203void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
204    int64_t delayUs = delayUsFromCurrentTime(timeUs);
205    sp<MediaPlayerBase> listener = mListener.promote();
206    if (listener != NULL) {
207        sp<AMessage> msg = new AMessage(kWhatSendSubtitle, id());
208        msg->setInt32("generation", mSendSubtitleGeneration);
209        if (parcel != NULL) {
210            msg->setObject("subtitle", parcel);
211        }
212        msg->setInt64("fireTimeUs", timeUs);
213        msg->post(delayUs);
214    }
215}
216
217int64_t TimedTextPlayer::delayUsFromCurrentTime(int64_t fireTimeUs) {
218    sp<MediaPlayerBase> listener = mListener.promote();
219    if (listener == NULL) {
220        // TODO: it may be better to return kInvalidTimeUs
221        return 0;
222    }
223    int32_t positionMs = 0;
224    listener->getCurrentPosition(&positionMs);
225    int64_t positionUs = positionMs * 1000ll;
226
227    if (fireTimeUs <= positionUs + kAdjustmentProcessingTimeUs) {
228        return 0;
229    } else {
230        int64_t delayUs = fireTimeUs - positionUs - kAdjustmentProcessingTimeUs;
231        if (delayUs > kMaxDelayUs) {
232            return kMaxDelayUs;
233        }
234        return delayUs;
235    }
236}
237
238void TimedTextPlayer::notifyError(int error) {
239    sp<MediaPlayerBase> listener = mListener.promote();
240    if (listener != NULL) {
241        listener->sendEvent(MEDIA_INFO, MEDIA_INFO_TIMED_TEXT_ERROR, error);
242    }
243}
244
245void TimedTextPlayer::notifyListener(const Parcel *parcel) {
246    sp<MediaPlayerBase> listener = mListener.promote();
247    if (listener != NULL) {
248        if (parcel != NULL && (parcel->dataSize() > 0)) {
249            listener->sendEvent(MEDIA_TIMED_TEXT, 0, 0, parcel);
250        } else {  // send an empty timed text to clear the screen
251            listener->sendEvent(MEDIA_TIMED_TEXT);
252        }
253    }
254}
255
256}  // namespace android
257