TimedTextPlayer.cpp revision bb6bc8491fe819f96e1902e56694715cb110ce94 
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", kInvalidTimeUs);
58    msg->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            mSendSubtitleGeneration++;
85            break;
86        }
87        case kWhatResume: {
88            doRead();
89            break;
90        }
91        case kWhatRetryRead: {
92            int32_t generation = -1;
93            CHECK(msg->findInt32("generation", &generation));
94            if (generation != mSendSubtitleGeneration) {
95                // Drop obsolete msg.
96                break;
97            }
98            int64_t seekTimeUs;
99            int seekMode;
100            if (msg->findInt64("seekTimeUs", &seekTimeUs) &&
101                msg->findInt32("seekMode", &seekMode)) {
102                MediaSource::ReadOptions options;
103                options.setSeekTo(
104                    seekTimeUs,
105                    static_cast<MediaSource::ReadOptions::SeekMode>(seekMode));
106                doRead(&options);
107            } else {
108                doRead();
109            }
110            break;
111        }
112        case kWhatSeek: {
113            mSendSubtitleGeneration++;
114            int64_t seekTimeUs = kInvalidTimeUs;
115            // Clear a displayed timed text before seeking.
116            notifyListener();
117            msg->findInt64("seekTimeUs", &seekTimeUs);
118            if (seekTimeUs == kInvalidTimeUs) {
119                sp<MediaPlayerBase> listener = mListener.promote();
120                if (listener != NULL) {
121                    int32_t positionMs = 0;
122                    listener->getCurrentPosition(&positionMs);
123                    seekTimeUs = positionMs * 1000ll;
124                }
125            }
126            doSeekAndRead(seekTimeUs);
127            break;
128        }
129        case kWhatSendSubtitle: {
130            int32_t generation;
131            CHECK(msg->findInt32("generation", &generation));
132            if (generation != mSendSubtitleGeneration) {
133                // Drop obsolete msg.
134                break;
135            }
136            // If current time doesn't reach to the fire time,
137            // re-post the message with the adjusted delay time.
138            int64_t fireTimeUs = kInvalidTimeUs;
139            if (msg->findInt64("fireTimeUs", &fireTimeUs)) {
140                // TODO: check if fireTimeUs is not kInvalidTimeUs.
141                int64_t delayUs = delayUsFromCurrentTime(fireTimeUs);
142                if (delayUs > 0) {
143                    msg->post(delayUs);
144                    break;
145                }
146            }
147            sp<RefBase> obj;
148            if (msg->findObject("subtitle", &obj)) {
149                sp<ParcelEvent> parcelEvent;
150                parcelEvent = static_cast<ParcelEvent*>(obj.get());
151                notifyListener(&(parcelEvent->parcel));
152                doRead();
153            } else {
154                notifyListener();
155            }
156            break;
157        }
158        case kWhatSetSource: {
159            sp<RefBase> obj;
160            msg->findObject("source", &obj);
161            if (obj == NULL) break;
162            if (mSource != NULL) {
163                mSource->stop();
164            }
165            mSource = static_cast<TimedTextSource*>(obj.get());
166            status_t err = mSource->start();
167            if (err != OK) {
168                notifyError(err);
169                break;
170            }
171            Parcel parcel;
172            err = mSource->extractGlobalDescriptions(&parcel);
173            if (err != OK) {
174                notifyError(err);
175                break;
176            }
177            notifyListener(&parcel);
178            break;
179        }
180    }
181}
182
183void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
184    MediaSource::ReadOptions options;
185    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
186    doRead(&options);
187}
188
189void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
190    int64_t startTimeUs = 0;
191    int64_t endTimeUs = 0;
192    sp<ParcelEvent> parcelEvent = new ParcelEvent();
193    status_t err = mSource->read(&startTimeUs, &endTimeUs,
194                                 &(parcelEvent->parcel), options);
195    if (err == WOULD_BLOCK) {
196        sp<AMessage> msg = new AMessage(kWhatRetryRead, id());
197        if (options != NULL) {
198            int64_t seekTimeUs = kInvalidTimeUs;
199            MediaSource::ReadOptions::SeekMode seekMode =
200                MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC;
201            CHECK(options->getSeekTo(&seekTimeUs, &seekMode));
202            msg->setInt64("seekTimeUs", seekTimeUs);
203            msg->setInt32("seekMode", seekMode);
204        }
205        msg->setInt32("generation", mSendSubtitleGeneration);
206        msg->post(kWaitTimeUsToRetryRead);
207        return;
208    } else if (err != OK) {
209        notifyError(err);
210        return;
211    }
212
213    postTextEvent(parcelEvent, startTimeUs);
214    if (endTimeUs > 0) {
215        CHECK_GE(endTimeUs, startTimeUs);
216        // send an empty timed text to clear the subtitle when it reaches to the
217        // end time.
218        postTextEvent(NULL, endTimeUs);
219    }
220}
221
222void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
223    int64_t delayUs = delayUsFromCurrentTime(timeUs);
224    sp<MediaPlayerBase> listener = mListener.promote();
225    if (listener != NULL) {
226        sp<AMessage> msg = new AMessage(kWhatSendSubtitle, id());
227        msg->setInt32("generation", mSendSubtitleGeneration);
228        if (parcel != NULL) {
229            msg->setObject("subtitle", parcel);
230        }
231        msg->setInt64("fireTimeUs", timeUs);
232        msg->post(delayUs);
233    }
234}
235
236int64_t TimedTextPlayer::delayUsFromCurrentTime(int64_t fireTimeUs) {
237    sp<MediaPlayerBase> listener = mListener.promote();
238    if (listener == NULL) {
239        // TODO: it may be better to return kInvalidTimeUs
240        return 0;
241    }
242    int32_t positionMs = 0;
243    listener->getCurrentPosition(&positionMs);
244    int64_t positionUs = positionMs * 1000ll;
245
246    if (fireTimeUs <= positionUs + kAdjustmentProcessingTimeUs) {
247        return 0;
248    } else {
249        int64_t delayUs = fireTimeUs - positionUs - kAdjustmentProcessingTimeUs;
250        if (delayUs > kMaxDelayUs) {
251            return kMaxDelayUs;
252        }
253        return delayUs;
254    }
255}
256
257void TimedTextPlayer::notifyError(int error) {
258    sp<MediaPlayerBase> listener = mListener.promote();
259    if (listener != NULL) {
260        listener->sendEvent(MEDIA_INFO, MEDIA_INFO_TIMED_TEXT_ERROR, error);
261    }
262}
263
264void TimedTextPlayer::notifyListener(const Parcel *parcel) {
265    sp<MediaPlayerBase> listener = mListener.promote();
266    if (listener != NULL) {
267        if (parcel != NULL && (parcel->dataSize() > 0)) {
268            listener->sendEvent(MEDIA_TIMED_TEXT, 0, 0, parcel);
269        } else {  // send an empty timed text to clear the screen
270            listener->sendEvent(MEDIA_TIMED_TEXT);
271        }
272    }
273}
274
275}  // namespace android
276