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 "TimedText3GPPSource"
19#include <utils/Log.h>
20
21#include <binder/Parcel.h>
22#include <media/stagefright/foundation/ADebug.h>  // CHECK_XX macro
23#include <media/stagefright/MediaBuffer.h>
24#include <media/stagefright/MediaDefs.h>  // for MEDIA_MIMETYPE_xxx
25#include <media/stagefright/MediaErrors.h>
26#include <media/stagefright/MediaSource.h>
27#include <media/stagefright/MetaData.h>
28
29#include "TimedText3GPPSource.h"
30#include "TextDescriptions.h"
31
32namespace android {
33
34TimedText3GPPSource::TimedText3GPPSource(const sp<MediaSource>& mediaSource)
35    : mSource(mediaSource) {
36}
37
38TimedText3GPPSource::~TimedText3GPPSource() {
39}
40
41status_t TimedText3GPPSource::read(
42        int64_t *startTimeUs, int64_t *endTimeUs, Parcel *parcel,
43        const MediaSource::ReadOptions *options) {
44    MediaBuffer *textBuffer = NULL;
45    status_t err = mSource->read(&textBuffer, options);
46    if (err != OK) {
47        return err;
48    }
49    CHECK(textBuffer != NULL);
50    textBuffer->meta_data()->findInt64(kKeyTime, startTimeUs);
51    CHECK_GE(*startTimeUs, 0);
52    extractAndAppendLocalDescriptions(*startTimeUs, textBuffer, parcel);
53    textBuffer->release();
54    // endTimeUs is a dummy parameter for 3gpp timed text format.
55    // Set a negative value to it to mark it is unavailable.
56    *endTimeUs = -1;
57    return OK;
58}
59
60// Each text sample consists of a string of text, optionally with sample
61// modifier description. The modifier description could specify a new
62// text style for the string of text. These descriptions are present only
63// if they are needed. This method is used to extract the modifier
64// description and append it at the end of the text.
65status_t TimedText3GPPSource::extractAndAppendLocalDescriptions(
66        int64_t timeUs, const MediaBuffer *textBuffer, Parcel *parcel) {
67    const void *data;
68    size_t size = 0;
69    int32_t flag = TextDescriptions::LOCAL_DESCRIPTIONS;
70
71    const char *mime;
72    CHECK(mSource->getFormat()->findCString(kKeyMIMEType, &mime));
73    CHECK(strcasecmp(mime, MEDIA_MIMETYPE_TEXT_3GPP) == 0);
74
75    data = textBuffer->data();
76    size = textBuffer->size();
77
78    if (size > 0) {
79      parcel->freeData();
80      flag |= TextDescriptions::IN_BAND_TEXT_3GPP;
81      return TextDescriptions::getParcelOfDescriptions(
82          (const uint8_t *)data, size, flag, timeUs / 1000, parcel);
83    }
84    return OK;
85}
86
87// To extract and send the global text descriptions for all the text samples
88// in the text track or text file.
89// TODO: send error message to application via notifyListener()...?
90status_t TimedText3GPPSource::extractGlobalDescriptions(Parcel *parcel) {
91    const void *data;
92    size_t size = 0;
93    int32_t flag = TextDescriptions::GLOBAL_DESCRIPTIONS;
94
95    const char *mime;
96    CHECK(mSource->getFormat()->findCString(kKeyMIMEType, &mime));
97    CHECK(strcasecmp(mime, MEDIA_MIMETYPE_TEXT_3GPP) == 0);
98
99    uint32_t type;
100    // get the 'tx3g' box content. This box contains the text descriptions
101    // used to render the text track
102    if (!mSource->getFormat()->findData(
103            kKeyTextFormatData, &type, &data, &size)) {
104        return ERROR_MALFORMED;
105    }
106
107    if (size > 0) {
108        flag |= TextDescriptions::IN_BAND_TEXT_3GPP;
109        return TextDescriptions::getParcelOfDescriptions(
110                (const uint8_t *)data, size, flag, 0, parcel);
111    }
112    return OK;
113}
114
115sp<MetaData> TimedText3GPPSource::getFormat() {
116    return mSource->getFormat();
117}
118
119}  // namespace android
120