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Merge "MPEG4Extractor:seek with empty edit list entry" into rvc-dev

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gugelfrei
TreeHugger Robot 4 years ago committed by Android (Google) Code Review
parent 8f612b453b 4f6a7e2158
commit ee650ee329
2 changed files with 82 additions and 55 deletions
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133
media/extractors/mp4/MPEG4Extractor.cpp
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@ -19,6 +19,7 @@
#include <ctype.h>
#include <inttypes.h>
#include <algorithm>
#include <memory>
#include <stdint.h>
#include <stdlib.h>
@ -149,9 +150,13 @@ private:
bool mIsAudio;
sp<ItemTable> mItemTable;
// Start offset from composition time to presentation time.
// Support shift only for video tracks through mElstShiftStartTicks for now.
/* Shift start offset (move to earlier time) when media_time > 0,
* in media time scale.
*/
uint64_t mElstShiftStartTicks;
/* Initial start offset (move to later time), empty edit list entry
* in media time scale.
*/
uint64_t mElstInitialEmptyEditTicks;
size_t parseNALSize(const uint8_t *data) const;
@ -1215,7 +1220,6 @@ status_t MPEG4Extractor::parseChunk(off64_t *offset, int depth) {
off64_t entriesoffset = data_offset + 8;
uint64_t segment_duration;
int64_t media_time;
uint64_t empty_edit_ticks = 0;
bool empty_edit_present = false;
for (int i = 0; i < entry_count; ++i) {
switch (version) {
@ -1247,45 +1251,37 @@ status_t MPEG4Extractor::parseChunk(off64_t *offset, int depth) {
}
// Empty edit entry would have to be first entry.
if (media_time == -1 && i == 0) {
int64_t durationUs;
if (AMediaFormat_getInt64(mFileMetaData, AMEDIAFORMAT_KEY_DURATION,
&durationUs)) {
empty_edit_ticks = segment_duration;
ALOGV("initial empty edit ticks: %" PRIu64, empty_edit_ticks);
empty_edit_present = true;
}
}
// Process second entry only when the first entry was an empty edit entry.
if (empty_edit_present && i == 1) {
int64_t durationUs;
if (AMediaFormat_getInt64(mLastTrack->meta, AMEDIAFORMAT_KEY_DURATION,
&durationUs) &&
mHeaderTimescale != 0) {
// Support only segment_duration<=track_duration and media_time==0 case.
uint64_t segmentDurationUs =
segment_duration * 1000000 / mHeaderTimescale;
if (segmentDurationUs == 0 || segmentDurationUs > durationUs ||
media_time != 0) {
ALOGW("for now, unsupported second entry in empty edit list");
}
}
empty_edit_present = true;
ALOGV("initial empty edit ticks: %" PRIu64, segment_duration);
/* In movie header timescale, and needs to be converted to media timescale
* after we get that from a track's 'mdhd' atom,
* which at times come after 'elst'.
*/
mLastTrack->elst_initial_empty_edit_ticks = segment_duration;
} else if (media_time >= 0 && i == 0) {
ALOGV("first edit list entry");
mLastTrack->elst_media_time = media_time;
mLastTrack->elst_segment_duration = segment_duration;
ALOGV("segment_duration: %" PRIu64 " media_time: %" PRId64,
segment_duration, media_time);
// media_time is in media timescale as are STTS/CTTS entries.
mLastTrack->elst_shift_start_ticks = media_time;
} else if (empty_edit_present && i == 1) {
// Process second entry only when the first entry was an empty edit entry.
ALOGV("second edit list entry");
mLastTrack->elst_media_time = media_time;
mLastTrack->elst_segment_duration = segment_duration;
ALOGV("segment_duration: %" PRIu64 " media_time: %" PRId64,
segment_duration, media_time);
mLastTrack->elst_shift_start_ticks = media_time;
} else {
ALOGW("for now, unsupported entry in edit list %" PRIu32, entry_count);
}
}
// save these for later, because the elst atom might precede
// the atoms that actually gives us the duration and sample rate
// needed to calculate the padding and delay values
mLastTrack->elst_needs_processing = true;
if (empty_edit_present) {
/* In movie header timescale, and needs to be converted to media timescale once
* we get that from a track's 'mdhd' atom, which at times come after 'elst'.
*/
mLastTrack->elst_initial_empty_edit_ticks = empty_edit_ticks;
} else {
mLastTrack->elst_media_time = media_time;
mLastTrack->elst_segment_duration = segment_duration;
ALOGV("segment_duration: %" PRIu64 " media_time: %" PRId64, segment_duration,
media_time);
}
}
break;
}
@ -4324,9 +4320,9 @@ MediaTrackHelper *MPEG4Extractor::getTrack(size_t index) {
}
}
// media_time is in media timescale as are STTS/CTTS entries.
track->elst_shift_start_ticks = track->elst_media_time;
ALOGV("track->elst_shift_start_ticks :%" PRIu64, track->elst_shift_start_ticks);
uint64_t elst_initial_empty_edit_ticks = 0;
if (mHeaderTimescale != 0) {
// Convert empty_edit_ticks from movie timescale to media timescale.
uint64_t elst_initial_empty_edit_ticks_mul = 0, elst_initial_empty_edit_ticks_add = 0;
@ -4337,15 +4333,15 @@ MediaTrackHelper *MPEG4Extractor::getTrack(size_t index) {
ALOGE("track->elst_initial_empty_edit_ticks overflow");
return nullptr;
}
track->elst_initial_empty_edit_ticks = elst_initial_empty_edit_ticks_add / mHeaderTimescale;
ALOGV("track->elst_initial_empty_edit_ticks :%" PRIu64,
track->elst_initial_empty_edit_ticks);
elst_initial_empty_edit_ticks = elst_initial_empty_edit_ticks_add / mHeaderTimescale;
}
ALOGV("elst_initial_empty_edit_ticks in MediaTimeScale :%" PRIu64,
elst_initial_empty_edit_ticks);
MPEG4Source* source =
new MPEG4Source(track->meta, mDataSource, track->timescale, track->sampleTable,
mSidxEntries, trex, mMoofOffset, itemTable,
track->elst_shift_start_ticks, track->elst_initial_empty_edit_ticks);
track->elst_shift_start_ticks, elst_initial_empty_edit_ticks);
if (source->init() != OK) {
delete source;
return NULL;
@ -5885,9 +5881,22 @@ media_status_t MPEG4Source::read(
break;
}
if( mode != ReadOptions::SEEK_FRAME_INDEX) {
seekTimeUs += ((long double)mElstShiftStartTicks * 1000000) / mTimescale;
ALOGV("shifted seekTimeUs :%" PRId64 ", mElstShiftStartTicks:%" PRIu64, seekTimeUs,
mElstShiftStartTicks);
int64_t elstInitialEmptyEditUs = 0, elstShiftStartUs = 0;
if (mElstInitialEmptyEditTicks > 0) {
elstInitialEmptyEditUs = ((long double)mElstInitialEmptyEditTicks * 1000000) /
mTimescale;
/* Sample's composition time from ctts/stts entries are non-negative(>=0).
* Hence, lower bound on seekTimeUs is 0.
*/
seekTimeUs = std::max(seekTimeUs - elstInitialEmptyEditUs, (int64_t)0);
}
if (mElstShiftStartTicks > 0) {
elstShiftStartUs = ((long double)mElstShiftStartTicks * 1000000) / mTimescale;
seekTimeUs += elstShiftStartUs;
}
ALOGV("shifted seekTimeUs:%" PRId64 ", elstInitialEmptyEditUs:%" PRIu64
", elstShiftStartUs:%" PRIu64, seekTimeUs, elstInitialEmptyEditUs,
elstShiftStartUs);
}
uint32_t sampleIndex;
@ -5933,7 +5942,12 @@ media_status_t MPEG4Source::read(
if (mode == ReadOptions::SEEK_CLOSEST
|| mode == ReadOptions::SEEK_FRAME_INDEX) {
sampleTime -= mElstShiftStartTicks;
if (mElstInitialEmptyEditTicks > 0) {
sampleTime += mElstInitialEmptyEditTicks;
}
if (mElstShiftStartTicks > 0){
sampleTime -= mElstShiftStartTicks;
}
targetSampleTimeUs = (sampleTime * 1000000ll) / mTimescale;
}
@ -5976,12 +5990,12 @@ media_status_t MPEG4Source::read(
if(err == OK) {
if (mElstInitialEmptyEditTicks > 0) {
cts += mElstInitialEmptyEditTicks;
} else {
}
if (mElstShiftStartTicks > 0) {
// cts can be negative. for example, initial audio samples for gapless playback.
cts -= (int64_t)mElstShiftStartTicks;
}
}
} else {
err = mItemTable->getImageOffsetAndSize(
options && options->getSeekTo(&seekTimeUs, &mode) ?
@ -6261,10 +6275,22 @@ media_status_t MPEG4Source::fragmentedRead(
int64_t seekTimeUs;
ReadOptions::SeekMode mode;
if (options && options->getSeekTo(&seekTimeUs, &mode)) {
seekTimeUs += ((long double)mElstShiftStartTicks * 1000000) / mTimescale;
ALOGV("shifted seekTimeUs :%" PRId64 ", mElstShiftStartTicks:%" PRIu64, seekTimeUs,
mElstShiftStartTicks);
int64_t elstInitialEmptyEditUs = 0, elstShiftStartUs = 0;
if (mElstInitialEmptyEditTicks > 0) {
elstInitialEmptyEditUs = ((long double)mElstInitialEmptyEditTicks * 1000000) /
mTimescale;
/* Sample's composition time from ctts/stts entries are non-negative(>=0).
* Hence, lower bound on seekTimeUs is 0.
*/
seekTimeUs = std::max(seekTimeUs - elstInitialEmptyEditUs, (int64_t)0);
}
if (mElstShiftStartTicks > 0){
elstShiftStartUs = ((long double)mElstShiftStartTicks * 1000000) / mTimescale;
seekTimeUs += elstShiftStartUs;
}
ALOGV("shifted seekTimeUs:%" PRId64 ", elstInitialEmptyEditUs:%" PRIu64
", elstShiftStartUs:%" PRIu64, seekTimeUs, elstInitialEmptyEditUs,
elstShiftStartUs);
int numSidxEntries = mSegments.size();
if (numSidxEntries != 0) {
@ -6355,7 +6381,8 @@ media_status_t MPEG4Source::fragmentedRead(
if (mElstInitialEmptyEditTicks > 0) {
cts += mElstInitialEmptyEditTicks;
} else {
}
if (mElstShiftStartTicks > 0) {
// cts can be negative. for example, initial audio samples for gapless playback.
cts -= (int64_t)mElstShiftStartTicks;
}

4
media/extractors/mp4/MPEG4Extractor.h
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@ -88,9 +88,9 @@ private:
*/
int64_t elst_media_time;
uint64_t elst_segment_duration;
// Shift start offset only when media_time > 0.
// Shift start offset (move to earlier time) when media_time > 0.
uint64_t elst_shift_start_ticks;
// Initial start offset, empty edit list entry.
// Initial start offset (move to later time), from empty edit list entry.
uint64_t elst_initial_empty_edit_ticks;
bool subsample_encryption;

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