TimedTextPlayer.cpp revision bae00e73c6d1d87cc5fd42b50f95d1d9572162ea 
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/timedtext/TimedTextDriver.h>
24#include <media/stagefright/MediaErrors.h>
25#include <media/MediaPlayerInterface.h>
26
27#include "TimedTextPlayer.h"
28
29#include "TimedTextSource.h"
30
31namespace android {
32
33static const int64_t kAdjustmentProcessingTimeUs = 100000ll;
34static const int64_t kWaitTimeUsToRetryRead = 100000ll;
35
36TimedTextPlayer::TimedTextPlayer(const wp<MediaPlayerBase> &listener)
37    : mListener(listener),
38      mSource(NULL),
39      mSendSubtitleGeneration(0) {
40}
41
42TimedTextPlayer::~TimedTextPlayer() {
43    if (mSource != NULL) {
44        mSource->stop();
45        mSource.clear();
46        mSource = NULL;
47    }
48}
49
50void TimedTextPlayer::start() {
51    sp<AMessage> msg = new AMessage(kWhatSeek, id());
52    msg->setInt64("seekTimeUs", -1);
53    msg->post();
54}
55
56void TimedTextPlayer::pause() {
57    (new AMessage(kWhatPause, id()))->post();
58}
59
60void TimedTextPlayer::seekToAsync(int64_t timeUs) {
61    sp<AMessage> msg = new AMessage(kWhatSeek, id());
62    msg->setInt64("seekTimeUs", timeUs);
63    msg->post();
64}
65
66void TimedTextPlayer::setDataSource(sp<TimedTextSource> source) {
67    sp<AMessage> msg = new AMessage(kWhatSetSource, id());
68    msg->setObject("source", source);
69    msg->post();
70}
71
72void TimedTextPlayer::onMessageReceived(const sp<AMessage> &msg) {
73    switch (msg->what()) {
74        case kWhatPause: {
75            mSendSubtitleGeneration++;
76            break;
77        }
78        case kWhatSeek: {
79            int64_t seekTimeUs = 0;
80            msg->findInt64("seekTimeUs", &seekTimeUs);
81            if (seekTimeUs < 0) {
82                sp<MediaPlayerBase> listener = mListener.promote();
83                if (listener != NULL) {
84                    int32_t positionMs = 0;
85                    listener->getCurrentPosition(&positionMs);
86                    seekTimeUs = positionMs * 1000ll;
87                }
88            }
89            doSeekAndRead(seekTimeUs);
90            break;
91        }
92        case kWhatSendSubtitle: {
93            int32_t generation;
94            CHECK(msg->findInt32("generation", &generation));
95            if (generation != mSendSubtitleGeneration) {
96              // Drop obsolete msg.
97              break;
98            }
99            sp<RefBase> obj;
100            msg->findObject("subtitle", &obj);
101            if (obj != NULL) {
102                sp<ParcelEvent> parcelEvent;
103                parcelEvent = static_cast<ParcelEvent*>(obj.get());
104                notifyListener(&(parcelEvent->parcel));
105            } else {
106                notifyListener();
107            }
108            doRead();
109            break;
110        }
111        case kWhatSetSource: {
112            sp<RefBase> obj;
113            msg->findObject("source", &obj);
114            if (obj == NULL) break;
115            if (mSource != NULL) {
116                mSource->stop();
117            }
118            mSource = static_cast<TimedTextSource*>(obj.get());
119            status_t err = mSource->start();
120            if (err != OK) {
121                notifyError(err);
122                break;
123            }
124            Parcel parcel;
125            err = mSource->extractGlobalDescriptions(&parcel);
126            if (err != OK) {
127                notifyError(err);
128                break;
129            }
130            notifyListener(&parcel);
131            break;
132        }
133    }
134}
135
136void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
137    MediaSource::ReadOptions options;
138    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
139    doRead(&options);
140}
141
142void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
143    int64_t startTimeUs = 0;
144    int64_t endTimeUs = 0;
145    sp<ParcelEvent> parcelEvent = new ParcelEvent();
146    status_t err = mSource->read(&startTimeUs, &endTimeUs,
147                                 &(parcelEvent->parcel), options);
148    if (err == WOULD_BLOCK) {
149        postTextEventDelayUs(NULL, kWaitTimeUsToRetryRead);
150        return;
151    } else if (err != OK) {
152        notifyError(err);
153        return;
154    }
155
156    postTextEvent(parcelEvent, startTimeUs);
157    if (endTimeUs > 0) {
158        CHECK_GE(endTimeUs, startTimeUs);
159        // send an empty timed text to clear the subtitle when it reaches to the
160        // end time.
161        postTextEvent(NULL, endTimeUs);
162    }
163}
164
165void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
166    sp<MediaPlayerBase> listener = mListener.promote();
167    if (listener != NULL) {
168        int64_t positionUs, delayUs;
169        int32_t positionMs = 0;
170        listener->getCurrentPosition(&positionMs);
171        positionUs = positionMs * 1000ll;
172
173        if (timeUs <= positionUs + kAdjustmentProcessingTimeUs) {
174            delayUs = 0;
175        } else {
176            delayUs = timeUs - positionUs - kAdjustmentProcessingTimeUs;
177        }
178        postTextEventDelayUs(parcel, delayUs);
179    }
180}
181
182void TimedTextPlayer::postTextEventDelayUs(const sp<ParcelEvent>& parcel, int64_t delayUs) {
183    sp<MediaPlayerBase> listener = mListener.promote();
184    if (listener != NULL) {
185        sp<AMessage> msg = new AMessage(kWhatSendSubtitle, id());
186        msg->setInt32("generation", mSendSubtitleGeneration);
187        if (parcel != NULL) {
188            msg->setObject("subtitle", parcel);
189        }
190        msg->post(delayUs);
191    }
192}
193
194void TimedTextPlayer::notifyError(int error) {
195    sp<MediaPlayerBase> listener = mListener.promote();
196    if (listener != NULL) {
197        listener->sendEvent(MEDIA_INFO, MEDIA_INFO_TIMED_TEXT_ERROR, error);
198    }
199}
200
201void TimedTextPlayer::notifyListener(const Parcel *parcel) {
202    sp<MediaPlayerBase> listener = mListener.promote();
203    if (listener != NULL) {
204        if (parcel != NULL && (parcel->dataSize() > 0)) {
205            listener->sendEvent(MEDIA_TIMED_TEXT, 0, 0, parcel);
206        } else {  // send an empty timed text to clear the screen
207            listener->sendEvent(MEDIA_TIMED_TEXT);
208        }
209    }
210}
211
212}  // namespace android
213