TimedTextPlayer.cpp revision 6472badc497a9e748411f8c8c9ed5d83ef335a85 
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      mPendingSeekTimeUs(kInvalidTimeUs),
45      mPaused(false),
46      mSendSubtitleGeneration(0) {
47}
48
49TimedTextPlayer::~TimedTextPlayer() {
50    if (mSource != NULL) {
51        mSource->stop();
52        mSource.clear();
53        mSource = NULL;
54    }
55}
56
57void TimedTextPlayer::start() {
58    (new AMessage(kWhatStart, id()))->post();
59}
60
61void TimedTextPlayer::pause() {
62    (new AMessage(kWhatPause, id()))->post();
63}
64
65void TimedTextPlayer::resume() {
66    (new AMessage(kWhatResume, id()))->post();
67}
68
69void TimedTextPlayer::seekToAsync(int64_t timeUs) {
70    sp<AMessage> msg = new AMessage(kWhatSeek, id());
71    msg->setInt64("seekTimeUs", timeUs);
72    msg->post();
73}
74
75void TimedTextPlayer::setDataSource(sp<TimedTextSource> source) {
76    sp<AMessage> msg = new AMessage(kWhatSetSource, id());
77    msg->setObject("source", source);
78    msg->post();
79}
80
81void TimedTextPlayer::onMessageReceived(const sp<AMessage> &msg) {
82    switch (msg->what()) {
83        case kWhatPause: {
84            mPaused = true;
85            break;
86        }
87        case kWhatResume: {
88            mPaused = false;
89            if (mPendingSeekTimeUs != kInvalidTimeUs) {
90                seekToAsync(mPendingSeekTimeUs);
91                mPendingSeekTimeUs = kInvalidTimeUs;
92            } else {
93                doRead();
94            }
95            break;
96        }
97        case kWhatStart: {
98            sp<MediaPlayerBase> listener = mListener.promote();
99            if (listener == NULL) {
100                ALOGE("Listener is NULL when kWhatStart is received.");
101                break;
102            }
103            mPaused = false;
104            mPendingSeekTimeUs = kInvalidTimeUs;
105            int32_t positionMs = 0;
106            listener->getCurrentPosition(&positionMs);
107            int64_t seekTimeUs = positionMs * 1000ll;
108
109            notifyListener();
110            mSendSubtitleGeneration++;
111            doSeekAndRead(seekTimeUs);
112            break;
113        }
114        case kWhatRetryRead: {
115            int32_t generation = -1;
116            CHECK(msg->findInt32("generation", &generation));
117            if (generation != mSendSubtitleGeneration) {
118                // Drop obsolete msg.
119                break;
120            }
121            int64_t seekTimeUs;
122            int seekMode;
123            if (msg->findInt64("seekTimeUs", &seekTimeUs) &&
124                msg->findInt32("seekMode", &seekMode)) {
125                MediaSource::ReadOptions options;
126                options.setSeekTo(
127                    seekTimeUs,
128                    static_cast<MediaSource::ReadOptions::SeekMode>(seekMode));
129                doRead(&options);
130            } else {
131                doRead();
132            }
133            break;
134        }
135        case kWhatSeek: {
136            int64_t seekTimeUs = kInvalidTimeUs;
137            // Clear a displayed timed text before seeking.
138            notifyListener();
139            msg->findInt64("seekTimeUs", &seekTimeUs);
140            if (seekTimeUs == kInvalidTimeUs) {
141                sp<MediaPlayerBase> listener = mListener.promote();
142                if (listener != NULL) {
143                    int32_t positionMs = 0;
144                    listener->getCurrentPosition(&positionMs);
145                    seekTimeUs = positionMs * 1000ll;
146                }
147            }
148            if (mPaused) {
149                mPendingSeekTimeUs = seekTimeUs;
150                break;
151            }
152            mSendSubtitleGeneration++;
153            doSeekAndRead(seekTimeUs);
154            break;
155        }
156        case kWhatSendSubtitle: {
157            int32_t generation;
158            CHECK(msg->findInt32("generation", &generation));
159            if (generation != mSendSubtitleGeneration) {
160                // Drop obsolete msg.
161                break;
162            }
163            // If current time doesn't reach to the fire time,
164            // re-post the message with the adjusted delay time.
165            int64_t fireTimeUs = kInvalidTimeUs;
166            if (msg->findInt64("fireTimeUs", &fireTimeUs)) {
167                // TODO: check if fireTimeUs is not kInvalidTimeUs.
168                int64_t delayUs = delayUsFromCurrentTime(fireTimeUs);
169                if (delayUs > 0) {
170                    msg->post(delayUs);
171                    break;
172                }
173            }
174            sp<RefBase> obj;
175            if (msg->findObject("subtitle", &obj)) {
176                sp<ParcelEvent> parcelEvent;
177                parcelEvent = static_cast<ParcelEvent*>(obj.get());
178                notifyListener(&(parcelEvent->parcel));
179                doRead();
180            } else {
181                notifyListener();
182            }
183            break;
184        }
185        case kWhatSetSource: {
186            sp<RefBase> obj;
187            msg->findObject("source", &obj);
188            if (obj == NULL) break;
189            if (mSource != NULL) {
190                mSource->stop();
191            }
192            mSource = static_cast<TimedTextSource*>(obj.get());
193            status_t err = mSource->start();
194            if (err != OK) {
195                notifyError(err);
196                break;
197            }
198            Parcel parcel;
199            err = mSource->extractGlobalDescriptions(&parcel);
200            if (err != OK) {
201                notifyError(err);
202                break;
203            }
204            notifyListener(&parcel);
205            break;
206        }
207    }
208}
209
210void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
211    MediaSource::ReadOptions options;
212    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
213    doRead(&options);
214}
215
216void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
217    int64_t startTimeUs = 0;
218    int64_t endTimeUs = 0;
219    sp<ParcelEvent> parcelEvent = new ParcelEvent();
220    status_t err = mSource->read(&startTimeUs, &endTimeUs,
221                                 &(parcelEvent->parcel), options);
222    if (err == WOULD_BLOCK) {
223        sp<AMessage> msg = new AMessage(kWhatRetryRead, id());
224        if (options != NULL) {
225            int64_t seekTimeUs = kInvalidTimeUs;
226            MediaSource::ReadOptions::SeekMode seekMode =
227                MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC;
228            CHECK(options->getSeekTo(&seekTimeUs, &seekMode));
229            msg->setInt64("seekTimeUs", seekTimeUs);
230            msg->setInt32("seekMode", seekMode);
231        }
232        msg->setInt32("generation", mSendSubtitleGeneration);
233        msg->post(kWaitTimeUsToRetryRead);
234        return;
235    } else if (err != OK) {
236        notifyError(err);
237        return;
238    }
239
240    postTextEvent(parcelEvent, startTimeUs);
241    if (endTimeUs > 0) {
242        CHECK_GE(endTimeUs, startTimeUs);
243        // send an empty timed text to clear the subtitle when it reaches to the
244        // end time.
245        postTextEvent(NULL, endTimeUs);
246    }
247}
248
249void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
250    int64_t delayUs = delayUsFromCurrentTime(timeUs);
251    sp<AMessage> msg = new AMessage(kWhatSendSubtitle, id());
252    msg->setInt32("generation", mSendSubtitleGeneration);
253    if (parcel != NULL) {
254        msg->setObject("subtitle", parcel);
255    }
256    msg->setInt64("fireTimeUs", timeUs);
257    msg->post(delayUs);
258}
259
260int64_t TimedTextPlayer::delayUsFromCurrentTime(int64_t fireTimeUs) {
261    sp<MediaPlayerBase> listener = mListener.promote();
262    if (listener == NULL) {
263        // TODO: it may be better to return kInvalidTimeUs
264        ALOGE("%s: Listener is NULL.", __FUNCTION__, fireTimeUs);
265        return 0;
266    }
267    int32_t positionMs = 0;
268    listener->getCurrentPosition(&positionMs);
269    int64_t positionUs = positionMs * 1000ll;
270
271    if (fireTimeUs <= positionUs + kAdjustmentProcessingTimeUs) {
272        return 0;
273    } else {
274        int64_t delayUs = fireTimeUs - positionUs - kAdjustmentProcessingTimeUs;
275        if (delayUs > kMaxDelayUs) {
276            return kMaxDelayUs;
277        }
278        return delayUs;
279    }
280}
281
282void TimedTextPlayer::notifyError(int error) {
283    sp<MediaPlayerBase> listener = mListener.promote();
284    if (listener == NULL) {
285        ALOGE("%s(error=%d): Listener is NULL.", __FUNCTION__, error);
286        return;
287    }
288    listener->sendEvent(MEDIA_INFO, MEDIA_INFO_TIMED_TEXT_ERROR, error);
289}
290
291void TimedTextPlayer::notifyListener(const Parcel *parcel) {
292    sp<MediaPlayerBase> listener = mListener.promote();
293    if (listener == NULL) {
294        ALOGE("%s: Listener is NULL.", __FUNCTION__);
295        return;
296    }
297    if (parcel != NULL && (parcel->dataSize() > 0)) {
298        listener->sendEvent(MEDIA_TIMED_TEXT, 0, 0, parcel);
299    } else {  // send an empty timed text to clear the screen
300        listener->sendEvent(MEDIA_TIMED_TEXT);
301    }
302}
303
304}  // namespace android
305