1/*
2 * Copyright (C) 2009 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_TAG "SampleTable"
18//#define LOG_NDEBUG 0
19#include <utils/Log.h>
20
21#include "include/SampleTable.h"
22#include "include/SampleIterator.h"
23
24#include <arpa/inet.h>
25
26#include <media/stagefright/foundation/ADebug.h>
27#include <media/stagefright/DataSource.h>
28#include <media/stagefright/Utils.h>
29
30namespace android {
31
32// static
33const uint32_t SampleTable::kChunkOffsetType32 = FOURCC('s', 't', 'c', 'o');
34// static
35const uint32_t SampleTable::kChunkOffsetType64 = FOURCC('c', 'o', '6', '4');
36// static
37const uint32_t SampleTable::kSampleSizeType32 = FOURCC('s', 't', 's', 'z');
38// static
39const uint32_t SampleTable::kSampleSizeTypeCompact = FOURCC('s', 't', 'z', '2');
40
41////////////////////////////////////////////////////////////////////////////////
42
43struct SampleTable::CompositionDeltaLookup {
44    CompositionDeltaLookup();
45
46    void setEntries(
47            const uint32_t *deltaEntries, size_t numDeltaEntries);
48
49    uint32_t getCompositionTimeOffset(uint32_t sampleIndex);
50
51private:
52    Mutex mLock;
53
54    const uint32_t *mDeltaEntries;
55    size_t mNumDeltaEntries;
56
57    size_t mCurrentDeltaEntry;
58    size_t mCurrentEntrySampleIndex;
59
60    DISALLOW_EVIL_CONSTRUCTORS(CompositionDeltaLookup);
61};
62
63SampleTable::CompositionDeltaLookup::CompositionDeltaLookup()
64    : mDeltaEntries(NULL),
65      mNumDeltaEntries(0),
66      mCurrentDeltaEntry(0),
67      mCurrentEntrySampleIndex(0) {
68}
69
70void SampleTable::CompositionDeltaLookup::setEntries(
71        const uint32_t *deltaEntries, size_t numDeltaEntries) {
72    Mutex::Autolock autolock(mLock);
73
74    mDeltaEntries = deltaEntries;
75    mNumDeltaEntries = numDeltaEntries;
76    mCurrentDeltaEntry = 0;
77    mCurrentEntrySampleIndex = 0;
78}
79
80uint32_t SampleTable::CompositionDeltaLookup::getCompositionTimeOffset(
81        uint32_t sampleIndex) {
82    Mutex::Autolock autolock(mLock);
83
84    if (mDeltaEntries == NULL) {
85        return 0;
86    }
87
88    if (sampleIndex < mCurrentEntrySampleIndex) {
89        mCurrentDeltaEntry = 0;
90        mCurrentEntrySampleIndex = 0;
91    }
92
93    while (mCurrentDeltaEntry < mNumDeltaEntries) {
94        uint32_t sampleCount = mDeltaEntries[2 * mCurrentDeltaEntry];
95        if (sampleIndex < mCurrentEntrySampleIndex + sampleCount) {
96            return mDeltaEntries[2 * mCurrentDeltaEntry + 1];
97        }
98
99        mCurrentEntrySampleIndex += sampleCount;
100        ++mCurrentDeltaEntry;
101    }
102
103    return 0;
104}
105
106////////////////////////////////////////////////////////////////////////////////
107
108SampleTable::SampleTable(const sp<DataSource> &source)
109    : mDataSource(source),
110      mChunkOffsetOffset(-1),
111      mChunkOffsetType(0),
112      mNumChunkOffsets(0),
113      mSampleToChunkOffset(-1),
114      mNumSampleToChunkOffsets(0),
115      mSampleSizeOffset(-1),
116      mSampleSizeFieldSize(0),
117      mDefaultSampleSize(0),
118      mNumSampleSizes(0),
119      mTimeToSampleCount(0),
120      mTimeToSample(NULL),
121      mSampleTimeEntries(NULL),
122      mCompositionTimeDeltaEntries(NULL),
123      mNumCompositionTimeDeltaEntries(0),
124      mCompositionDeltaLookup(new CompositionDeltaLookup),
125      mSyncSampleOffset(-1),
126      mNumSyncSamples(0),
127      mSyncSamples(NULL),
128      mLastSyncSampleIndex(0),
129      mSampleToChunkEntries(NULL) {
130    mSampleIterator = new SampleIterator(this);
131}
132
133SampleTable::~SampleTable() {
134    delete[] mSampleToChunkEntries;
135    mSampleToChunkEntries = NULL;
136
137    delete[] mSyncSamples;
138    mSyncSamples = NULL;
139
140    delete mCompositionDeltaLookup;
141    mCompositionDeltaLookup = NULL;
142
143    delete[] mCompositionTimeDeltaEntries;
144    mCompositionTimeDeltaEntries = NULL;
145
146    delete[] mSampleTimeEntries;
147    mSampleTimeEntries = NULL;
148
149    delete[] mTimeToSample;
150    mTimeToSample = NULL;
151
152    delete mSampleIterator;
153    mSampleIterator = NULL;
154}
155
156bool SampleTable::isValid() const {
157    return mChunkOffsetOffset >= 0
158        && mSampleToChunkOffset >= 0
159        && mSampleSizeOffset >= 0
160        && mTimeToSample != NULL;
161}
162
163status_t SampleTable::setChunkOffsetParams(
164        uint32_t type, off64_t data_offset, size_t data_size) {
165    if (mChunkOffsetOffset >= 0) {
166        return ERROR_MALFORMED;
167    }
168
169    CHECK(type == kChunkOffsetType32 || type == kChunkOffsetType64);
170
171    mChunkOffsetOffset = data_offset;
172    mChunkOffsetType = type;
173
174    if (data_size < 8) {
175        return ERROR_MALFORMED;
176    }
177
178    uint8_t header[8];
179    if (mDataSource->readAt(
180                data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
181        return ERROR_IO;
182    }
183
184    if (U32_AT(header) != 0) {
185        // Expected version = 0, flags = 0.
186        return ERROR_MALFORMED;
187    }
188
189    mNumChunkOffsets = U32_AT(&header[4]);
190
191    if (mChunkOffsetType == kChunkOffsetType32) {
192        if (data_size < 8 + mNumChunkOffsets * 4) {
193            return ERROR_MALFORMED;
194        }
195    } else {
196        if (data_size < 8 + mNumChunkOffsets * 8) {
197            return ERROR_MALFORMED;
198        }
199    }
200
201    return OK;
202}
203
204status_t SampleTable::setSampleToChunkParams(
205        off64_t data_offset, size_t data_size) {
206    if (mSampleToChunkOffset >= 0) {
207        return ERROR_MALFORMED;
208    }
209
210    mSampleToChunkOffset = data_offset;
211
212    if (data_size < 8) {
213        return ERROR_MALFORMED;
214    }
215
216    uint8_t header[8];
217    if (mDataSource->readAt(
218                data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
219        return ERROR_IO;
220    }
221
222    if (U32_AT(header) != 0) {
223        // Expected version = 0, flags = 0.
224        return ERROR_MALFORMED;
225    }
226
227    mNumSampleToChunkOffsets = U32_AT(&header[4]);
228
229    if (data_size < 8 + mNumSampleToChunkOffsets * 12) {
230        return ERROR_MALFORMED;
231    }
232
233    mSampleToChunkEntries =
234        new SampleToChunkEntry[mNumSampleToChunkOffsets];
235
236    for (uint32_t i = 0; i < mNumSampleToChunkOffsets; ++i) {
237        uint8_t buffer[12];
238        if (mDataSource->readAt(
239                    mSampleToChunkOffset + 8 + i * 12, buffer, sizeof(buffer))
240                != (ssize_t)sizeof(buffer)) {
241            return ERROR_IO;
242        }
243
244        CHECK(U32_AT(buffer) >= 1);  // chunk index is 1 based in the spec.
245
246        // We want the chunk index to be 0-based.
247        mSampleToChunkEntries[i].startChunk = U32_AT(buffer) - 1;
248        mSampleToChunkEntries[i].samplesPerChunk = U32_AT(&buffer[4]);
249        mSampleToChunkEntries[i].chunkDesc = U32_AT(&buffer[8]);
250    }
251
252    return OK;
253}
254
255status_t SampleTable::setSampleSizeParams(
256        uint32_t type, off64_t data_offset, size_t data_size) {
257    if (mSampleSizeOffset >= 0) {
258        return ERROR_MALFORMED;
259    }
260
261    CHECK(type == kSampleSizeType32 || type == kSampleSizeTypeCompact);
262
263    mSampleSizeOffset = data_offset;
264
265    if (data_size < 12) {
266        return ERROR_MALFORMED;
267    }
268
269    uint8_t header[12];
270    if (mDataSource->readAt(
271                data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
272        return ERROR_IO;
273    }
274
275    if (U32_AT(header) != 0) {
276        // Expected version = 0, flags = 0.
277        return ERROR_MALFORMED;
278    }
279
280    mDefaultSampleSize = U32_AT(&header[4]);
281    mNumSampleSizes = U32_AT(&header[8]);
282
283    if (type == kSampleSizeType32) {
284        mSampleSizeFieldSize = 32;
285
286        if (mDefaultSampleSize != 0) {
287            return OK;
288        }
289
290        if (data_size < 12 + mNumSampleSizes * 4) {
291            return ERROR_MALFORMED;
292        }
293    } else {
294        if ((mDefaultSampleSize & 0xffffff00) != 0) {
295            // The high 24 bits are reserved and must be 0.
296            return ERROR_MALFORMED;
297        }
298
299        mSampleSizeFieldSize = mDefaultSampleSize & 0xff;
300        mDefaultSampleSize = 0;
301
302        if (mSampleSizeFieldSize != 4 && mSampleSizeFieldSize != 8
303            && mSampleSizeFieldSize != 16) {
304            return ERROR_MALFORMED;
305        }
306
307        if (data_size < 12 + (mNumSampleSizes * mSampleSizeFieldSize + 4) / 8) {
308            return ERROR_MALFORMED;
309        }
310    }
311
312    return OK;
313}
314
315status_t SampleTable::setTimeToSampleParams(
316        off64_t data_offset, size_t data_size) {
317    if (mTimeToSample != NULL || data_size < 8) {
318        return ERROR_MALFORMED;
319    }
320
321    uint8_t header[8];
322    if (mDataSource->readAt(
323                data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
324        return ERROR_IO;
325    }
326
327    if (U32_AT(header) != 0) {
328        // Expected version = 0, flags = 0.
329        return ERROR_MALFORMED;
330    }
331
332    mTimeToSampleCount = U32_AT(&header[4]);
333    uint64_t allocSize = mTimeToSampleCount * 2 * sizeof(uint32_t);
334    if (allocSize > SIZE_MAX) {
335        return ERROR_OUT_OF_RANGE;
336    }
337    mTimeToSample = new uint32_t[mTimeToSampleCount * 2];
338
339    size_t size = sizeof(uint32_t) * mTimeToSampleCount * 2;
340    if (mDataSource->readAt(
341                data_offset + 8, mTimeToSample, size) < (ssize_t)size) {
342        return ERROR_IO;
343    }
344
345    for (uint32_t i = 0; i < mTimeToSampleCount * 2; ++i) {
346        mTimeToSample[i] = ntohl(mTimeToSample[i]);
347    }
348
349    return OK;
350}
351
352status_t SampleTable::setCompositionTimeToSampleParams(
353        off64_t data_offset, size_t data_size) {
354    ALOGI("There are reordered frames present.");
355
356    if (mCompositionTimeDeltaEntries != NULL || data_size < 8) {
357        return ERROR_MALFORMED;
358    }
359
360    uint8_t header[8];
361    if (mDataSource->readAt(
362                data_offset, header, sizeof(header))
363            < (ssize_t)sizeof(header)) {
364        return ERROR_IO;
365    }
366
367    if (U32_AT(header) != 0) {
368        // Expected version = 0, flags = 0.
369        return ERROR_MALFORMED;
370    }
371
372    size_t numEntries = U32_AT(&header[4]);
373
374    if (data_size != (numEntries + 1) * 8) {
375        return ERROR_MALFORMED;
376    }
377
378    mNumCompositionTimeDeltaEntries = numEntries;
379    uint64_t allocSize = numEntries * 2 * sizeof(uint32_t);
380    if (allocSize > SIZE_MAX) {
381        return ERROR_OUT_OF_RANGE;
382    }
383
384    mCompositionTimeDeltaEntries = new uint32_t[2 * numEntries];
385
386    if (mDataSource->readAt(
387                data_offset + 8, mCompositionTimeDeltaEntries, numEntries * 8)
388            < (ssize_t)numEntries * 8) {
389        delete[] mCompositionTimeDeltaEntries;
390        mCompositionTimeDeltaEntries = NULL;
391
392        return ERROR_IO;
393    }
394
395    for (size_t i = 0; i < 2 * numEntries; ++i) {
396        mCompositionTimeDeltaEntries[i] = ntohl(mCompositionTimeDeltaEntries[i]);
397    }
398
399    mCompositionDeltaLookup->setEntries(
400            mCompositionTimeDeltaEntries, mNumCompositionTimeDeltaEntries);
401
402    return OK;
403}
404
405status_t SampleTable::setSyncSampleParams(off64_t data_offset, size_t data_size) {
406    if (mSyncSampleOffset >= 0 || data_size < 8) {
407        return ERROR_MALFORMED;
408    }
409
410    mSyncSampleOffset = data_offset;
411
412    uint8_t header[8];
413    if (mDataSource->readAt(
414                data_offset, header, sizeof(header)) < (ssize_t)sizeof(header)) {
415        return ERROR_IO;
416    }
417
418    if (U32_AT(header) != 0) {
419        // Expected version = 0, flags = 0.
420        return ERROR_MALFORMED;
421    }
422
423    mNumSyncSamples = U32_AT(&header[4]);
424
425    if (mNumSyncSamples < 2) {
426        ALOGV("Table of sync samples is empty or has only a single entry!");
427    }
428
429    uint64_t allocSize = mNumSyncSamples * sizeof(uint32_t);
430    if (allocSize > SIZE_MAX) {
431        return ERROR_OUT_OF_RANGE;
432    }
433
434    mSyncSamples = new uint32_t[mNumSyncSamples];
435    size_t size = mNumSyncSamples * sizeof(uint32_t);
436    if (mDataSource->readAt(mSyncSampleOffset + 8, mSyncSamples, size)
437            != (ssize_t)size) {
438        return ERROR_IO;
439    }
440
441    for (size_t i = 0; i < mNumSyncSamples; ++i) {
442        mSyncSamples[i] = ntohl(mSyncSamples[i]) - 1;
443    }
444
445    return OK;
446}
447
448uint32_t SampleTable::countChunkOffsets() const {
449    return mNumChunkOffsets;
450}
451
452uint32_t SampleTable::countSamples() const {
453    return mNumSampleSizes;
454}
455
456status_t SampleTable::getMaxSampleSize(size_t *max_size) {
457    Mutex::Autolock autoLock(mLock);
458
459    *max_size = 0;
460
461    for (uint32_t i = 0; i < mNumSampleSizes; ++i) {
462        size_t sample_size;
463        status_t err = getSampleSize_l(i, &sample_size);
464
465        if (err != OK) {
466            return err;
467        }
468
469        if (sample_size > *max_size) {
470            *max_size = sample_size;
471        }
472    }
473
474    return OK;
475}
476
477uint32_t abs_difference(uint32_t time1, uint32_t time2) {
478    return time1 > time2 ? time1 - time2 : time2 - time1;
479}
480
481// static
482int SampleTable::CompareIncreasingTime(const void *_a, const void *_b) {
483    const SampleTimeEntry *a = (const SampleTimeEntry *)_a;
484    const SampleTimeEntry *b = (const SampleTimeEntry *)_b;
485
486    if (a->mCompositionTime < b->mCompositionTime) {
487        return -1;
488    } else if (a->mCompositionTime > b->mCompositionTime) {
489        return 1;
490    }
491
492    return 0;
493}
494
495void SampleTable::buildSampleEntriesTable() {
496    Mutex::Autolock autoLock(mLock);
497
498    if (mSampleTimeEntries != NULL) {
499        return;
500    }
501
502    mSampleTimeEntries = new SampleTimeEntry[mNumSampleSizes];
503
504    uint32_t sampleIndex = 0;
505    uint32_t sampleTime = 0;
506
507    for (uint32_t i = 0; i < mTimeToSampleCount; ++i) {
508        uint32_t n = mTimeToSample[2 * i];
509        uint32_t delta = mTimeToSample[2 * i + 1];
510
511        for (uint32_t j = 0; j < n; ++j) {
512            if (sampleIndex < mNumSampleSizes) {
513                // Technically this should always be the case if the file
514                // is well-formed, but you know... there's (gasp) malformed
515                // content out there.
516
517                mSampleTimeEntries[sampleIndex].mSampleIndex = sampleIndex;
518
519                uint32_t compTimeDelta =
520                    mCompositionDeltaLookup->getCompositionTimeOffset(
521                            sampleIndex);
522
523                mSampleTimeEntries[sampleIndex].mCompositionTime =
524                    sampleTime + compTimeDelta;
525            }
526
527            ++sampleIndex;
528            sampleTime += delta;
529        }
530    }
531
532    qsort(mSampleTimeEntries, mNumSampleSizes, sizeof(SampleTimeEntry),
533          CompareIncreasingTime);
534}
535
536status_t SampleTable::findSampleAtTime(
537        uint64_t req_time, uint64_t scale_num, uint64_t scale_den,
538        uint32_t *sample_index, uint32_t flags) {
539    buildSampleEntriesTable();
540
541    uint32_t left = 0;
542    uint32_t right_plus_one = mNumSampleSizes;
543    while (left < right_plus_one) {
544        uint32_t center = left + (right_plus_one - left) / 2;
545        uint64_t centerTime =
546            getSampleTime(center, scale_num, scale_den);
547
548        if (req_time < centerTime) {
549            right_plus_one = center;
550        } else if (req_time > centerTime) {
551            left = center + 1;
552        } else {
553            *sample_index = mSampleTimeEntries[center].mSampleIndex;
554            return OK;
555        }
556    }
557
558    uint32_t closestIndex = left;
559
560    if (closestIndex == mNumSampleSizes) {
561        if (flags == kFlagAfter) {
562            return ERROR_OUT_OF_RANGE;
563        }
564        flags = kFlagBefore;
565    } else if (closestIndex == 0) {
566        if (flags == kFlagBefore) {
567            // normally we should return out of range, but that is
568            // treated as end-of-stream.  instead return first sample
569            //
570            // return ERROR_OUT_OF_RANGE;
571        }
572        flags = kFlagAfter;
573    }
574
575    switch (flags) {
576        case kFlagBefore:
577        {
578            --closestIndex;
579            break;
580        }
581
582        case kFlagAfter:
583        {
584            // nothing to do
585            break;
586        }
587
588        default:
589        {
590            CHECK(flags == kFlagClosest);
591            // pick closest based on timestamp. use abs_difference for safety
592            if (abs_difference(
593                    getSampleTime(closestIndex, scale_num, scale_den), req_time) >
594                abs_difference(
595                    req_time, getSampleTime(closestIndex - 1, scale_num, scale_den))) {
596                --closestIndex;
597            }
598            break;
599        }
600    }
601
602    *sample_index = mSampleTimeEntries[closestIndex].mSampleIndex;
603    return OK;
604}
605
606status_t SampleTable::findSyncSampleNear(
607        uint32_t start_sample_index, uint32_t *sample_index, uint32_t flags) {
608    Mutex::Autolock autoLock(mLock);
609
610    *sample_index = 0;
611
612    if (mSyncSampleOffset < 0) {
613        // All samples are sync-samples.
614        *sample_index = start_sample_index;
615        return OK;
616    }
617
618    if (mNumSyncSamples == 0) {
619        *sample_index = 0;
620        return OK;
621    }
622
623    uint32_t left = 0;
624    uint32_t right_plus_one = mNumSyncSamples;
625    while (left < right_plus_one) {
626        uint32_t center = left + (right_plus_one - left) / 2;
627        uint32_t x = mSyncSamples[center];
628
629        if (start_sample_index < x) {
630            right_plus_one = center;
631        } else if (start_sample_index > x) {
632            left = center + 1;
633        } else {
634            *sample_index = x;
635            return OK;
636        }
637    }
638
639    if (left == mNumSyncSamples) {
640        if (flags == kFlagAfter) {
641            ALOGE("tried to find a sync frame after the last one: %d", left);
642            return ERROR_OUT_OF_RANGE;
643        }
644        flags = kFlagBefore;
645    }
646    else if (left == 0) {
647        if (flags == kFlagBefore) {
648            ALOGE("tried to find a sync frame before the first one: %d", left);
649
650            // normally we should return out of range, but that is
651            // treated as end-of-stream.  instead seek to first sync
652            //
653            // return ERROR_OUT_OF_RANGE;
654        }
655        flags = kFlagAfter;
656    }
657
658    // Now ssi[left - 1] <(=) start_sample_index <= ssi[left]
659    switch (flags) {
660        case kFlagBefore:
661        {
662            --left;
663            break;
664        }
665        case kFlagAfter:
666        {
667            // nothing to do
668            break;
669        }
670        default:
671        {
672            // this route is not used, but implement it nonetheless
673            CHECK(flags == kFlagClosest);
674
675            status_t err = mSampleIterator->seekTo(start_sample_index);
676            if (err != OK) {
677                return err;
678            }
679            uint32_t sample_time = mSampleIterator->getSampleTime();
680
681            err = mSampleIterator->seekTo(mSyncSamples[left]);
682            if (err != OK) {
683                return err;
684            }
685            uint32_t upper_time = mSampleIterator->getSampleTime();
686
687            err = mSampleIterator->seekTo(mSyncSamples[left - 1]);
688            if (err != OK) {
689                return err;
690            }
691            uint32_t lower_time = mSampleIterator->getSampleTime();
692
693            // use abs_difference for safety
694            if (abs_difference(upper_time, sample_time) >
695                abs_difference(sample_time, lower_time)) {
696                --left;
697            }
698            break;
699        }
700    }
701
702    *sample_index = mSyncSamples[left];
703    return OK;
704}
705
706status_t SampleTable::findThumbnailSample(uint32_t *sample_index) {
707    Mutex::Autolock autoLock(mLock);
708
709    if (mSyncSampleOffset < 0) {
710        // All samples are sync-samples.
711        *sample_index = 0;
712        return OK;
713    }
714
715    uint32_t bestSampleIndex = 0;
716    size_t maxSampleSize = 0;
717
718    static const size_t kMaxNumSyncSamplesToScan = 20;
719
720    // Consider the first kMaxNumSyncSamplesToScan sync samples and
721    // pick the one with the largest (compressed) size as the thumbnail.
722
723    size_t numSamplesToScan = mNumSyncSamples;
724    if (numSamplesToScan > kMaxNumSyncSamplesToScan) {
725        numSamplesToScan = kMaxNumSyncSamplesToScan;
726    }
727
728    for (size_t i = 0; i < numSamplesToScan; ++i) {
729        uint32_t x = mSyncSamples[i];
730
731        // Now x is a sample index.
732        size_t sampleSize;
733        status_t err = getSampleSize_l(x, &sampleSize);
734        if (err != OK) {
735            return err;
736        }
737
738        if (i == 0 || sampleSize > maxSampleSize) {
739            bestSampleIndex = x;
740            maxSampleSize = sampleSize;
741        }
742    }
743
744    *sample_index = bestSampleIndex;
745
746    return OK;
747}
748
749status_t SampleTable::getSampleSize_l(
750        uint32_t sampleIndex, size_t *sampleSize) {
751    return mSampleIterator->getSampleSizeDirect(
752            sampleIndex, sampleSize);
753}
754
755status_t SampleTable::getMetaDataForSample(
756        uint32_t sampleIndex,
757        off64_t *offset,
758        size_t *size,
759        uint32_t *compositionTime,
760        bool *isSyncSample,
761        uint32_t *sampleDuration) {
762    Mutex::Autolock autoLock(mLock);
763
764    status_t err;
765    if ((err = mSampleIterator->seekTo(sampleIndex)) != OK) {
766        return err;
767    }
768
769    if (offset) {
770        *offset = mSampleIterator->getSampleOffset();
771    }
772
773    if (size) {
774        *size = mSampleIterator->getSampleSize();
775    }
776
777    if (compositionTime) {
778        *compositionTime = mSampleIterator->getSampleTime();
779    }
780
781    if (isSyncSample) {
782        *isSyncSample = false;
783        if (mSyncSampleOffset < 0) {
784            // Every sample is a sync sample.
785            *isSyncSample = true;
786        } else {
787            size_t i = (mLastSyncSampleIndex < mNumSyncSamples)
788                    && (mSyncSamples[mLastSyncSampleIndex] <= sampleIndex)
789                ? mLastSyncSampleIndex : 0;
790
791            while (i < mNumSyncSamples && mSyncSamples[i] < sampleIndex) {
792                ++i;
793            }
794
795            if (i < mNumSyncSamples && mSyncSamples[i] == sampleIndex) {
796                *isSyncSample = true;
797            }
798
799            mLastSyncSampleIndex = i;
800        }
801    }
802
803    if (sampleDuration) {
804        *sampleDuration = mSampleIterator->getSampleDuration();
805    }
806
807    return OK;
808}
809
810uint32_t SampleTable::getCompositionTimeOffset(uint32_t sampleIndex) {
811    return mCompositionDeltaLookup->getCompositionTimeOffset(sampleIndex);
812}
813
814}  // namespace android
815
816