TimedTextPlayer.cpp revision c4ddeeb06a9defc359e99d1ce20882e1d688d1b3 
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 kWhatRetryRead: {
79            int64_t seekTimeUs;
80            int seekMode;
81            if (msg->findInt64("seekTimeUs", &seekTimeUs) &&
82                msg->findInt32("seekMode", &seekMode)) {
83                MediaSource::ReadOptions options;
84                options.setSeekTo(
85                    seekTimeUs,
86                    static_cast<MediaSource::ReadOptions::SeekMode>(seekMode));
87                doRead(&options);
88            } else {
89                doRead();
90            }
91            break;
92        }
93        case kWhatSeek: {
94            int64_t seekTimeUs = 0;
95            msg->findInt64("seekTimeUs", &seekTimeUs);
96            if (seekTimeUs < 0) {
97                sp<MediaPlayerBase> listener = mListener.promote();
98                if (listener != NULL) {
99                    int32_t positionMs = 0;
100                    listener->getCurrentPosition(&positionMs);
101                    seekTimeUs = positionMs * 1000ll;
102                }
103            }
104            doSeekAndRead(seekTimeUs);
105            break;
106        }
107        case kWhatSendSubtitle: {
108            int32_t generation;
109            CHECK(msg->findInt32("generation", &generation));
110            if (generation != mSendSubtitleGeneration) {
111              // Drop obsolete msg.
112              break;
113            }
114            sp<RefBase> obj;
115            if (msg->findObject("subtitle", &obj)) {
116                sp<ParcelEvent> parcelEvent;
117                parcelEvent = static_cast<ParcelEvent*>(obj.get());
118                notifyListener(&(parcelEvent->parcel));
119                doRead();
120            } else {
121                notifyListener();
122            }
123            break;
124        }
125        case kWhatSetSource: {
126            sp<RefBase> obj;
127            msg->findObject("source", &obj);
128            if (obj == NULL) break;
129            if (mSource != NULL) {
130                mSource->stop();
131            }
132            mSource = static_cast<TimedTextSource*>(obj.get());
133            status_t err = mSource->start();
134            if (err != OK) {
135                notifyError(err);
136                break;
137            }
138            Parcel parcel;
139            err = mSource->extractGlobalDescriptions(&parcel);
140            if (err != OK) {
141                notifyError(err);
142                break;
143            }
144            notifyListener(&parcel);
145            break;
146        }
147    }
148}
149
150void TimedTextPlayer::doSeekAndRead(int64_t seekTimeUs) {
151    MediaSource::ReadOptions options;
152    options.setSeekTo(seekTimeUs, MediaSource::ReadOptions::SEEK_PREVIOUS_SYNC);
153    doRead(&options);
154}
155
156void TimedTextPlayer::doRead(MediaSource::ReadOptions* options) {
157    int64_t startTimeUs = 0;
158    int64_t endTimeUs = 0;
159    sp<ParcelEvent> parcelEvent = new ParcelEvent();
160    status_t err = mSource->read(&startTimeUs, &endTimeUs,
161                                 &(parcelEvent->parcel), options);
162    if (err == WOULD_BLOCK) {
163        sp<AMessage> msg = new AMessage(kWhatRetryRead);
164        if (options != NULL) {
165            int64_t seekTimeUs;
166            MediaSource::ReadOptions::SeekMode seekMode;
167            CHECK(options->getSeekTo(&seekTimeUs, &seekMode));
168            msg->setInt64("seekTimeUs", seekTimeUs);
169            msg->setInt32("seekMode", seekMode);
170        }
171        msg->post(kWaitTimeUsToRetryRead);
172        return;
173    } else if (err != OK) {
174        notifyError(err);
175        return;
176    }
177
178    postTextEvent(parcelEvent, startTimeUs);
179    if (endTimeUs > 0) {
180        CHECK_GE(endTimeUs, startTimeUs);
181        // send an empty timed text to clear the subtitle when it reaches to the
182        // end time.
183        postTextEvent(NULL, endTimeUs);
184    }
185}
186
187void TimedTextPlayer::postTextEvent(const sp<ParcelEvent>& parcel, int64_t timeUs) {
188    sp<MediaPlayerBase> listener = mListener.promote();
189    if (listener != NULL) {
190        int64_t positionUs, delayUs;
191        int32_t positionMs = 0;
192        listener->getCurrentPosition(&positionMs);
193        positionUs = positionMs * 1000ll;
194
195        if (timeUs <= positionUs + kAdjustmentProcessingTimeUs) {
196            delayUs = 0;
197        } else {
198            delayUs = timeUs - positionUs - kAdjustmentProcessingTimeUs;
199        }
200        postTextEventDelayUs(parcel, delayUs);
201    }
202}
203
204void TimedTextPlayer::postTextEventDelayUs(const sp<ParcelEvent>& parcel, int64_t delayUs) {
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->post(delayUs);
213    }
214}
215
216void TimedTextPlayer::notifyError(int error) {
217    sp<MediaPlayerBase> listener = mListener.promote();
218    if (listener != NULL) {
219        listener->sendEvent(MEDIA_INFO, MEDIA_INFO_TIMED_TEXT_ERROR, error);
220    }
221}
222
223void TimedTextPlayer::notifyListener(const Parcel *parcel) {
224    sp<MediaPlayerBase> listener = mListener.promote();
225    if (listener != NULL) {
226        if (parcel != NULL && (parcel->dataSize() > 0)) {
227            listener->sendEvent(MEDIA_TIMED_TEXT, 0, 0, parcel);
228        } else {  // send an empty timed text to clear the screen
229            listener->sendEvent(MEDIA_TIMED_TEXT);
230        }
231    }
232}
233
234}  // namespace android
235