shaka-packager/media/mp4/decoding_time_iterator.cc

69 lines
1.9 KiB
C++

// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "media/mp4/decoding_time_iterator.h"
#include <algorithm>
#include "base/logging.h"
namespace media {
namespace mp4 {
DecodingTimeIterator::DecodingTimeIterator(
const DecodingTimeToSample& decoding_time_to_sample)
: sample_index_(0),
decoding_time_table_(decoding_time_to_sample.decoding_time),
iterator_(decoding_time_table_.begin()) {
}
bool DecodingTimeIterator::AdvanceSample() {
++sample_index_;
if (sample_index_ >= iterator_->sample_count) {
++iterator_;
if (iterator_ == decoding_time_table_.end())
return false;
sample_index_ = 0;
}
return true;
}
bool DecodingTimeIterator::IsValid() {
return iterator_ != decoding_time_table_.end()
&& sample_index_ < iterator_->sample_count;
}
uint64 DecodingTimeIterator::Duration(uint32 start_sample, uint32 end_sample) {
DCHECK(start_sample <= end_sample);
uint32 current_sample = 0;
uint32 prev_sample = 0;
uint64 duration = 0;
std::vector<DecodingTime>::const_iterator it = decoding_time_table_.begin();
for (; it != decoding_time_table_.end(); ++it) {
current_sample += it->sample_count;
if (current_sample >= start_sample) {
duration += (std::min(end_sample, current_sample)
- std::max(start_sample, prev_sample + 1) + 1) * it->sample_delta;
if (current_sample >= end_sample)
break;
}
prev_sample = current_sample;
}
return duration;
}
uint32 DecodingTimeIterator::NumSamples() {
uint32 num_samples = 0;
std::vector<DecodingTime>::const_iterator it = decoding_time_table_.begin();
for (; it != decoding_time_table_.end(); ++it) {
num_samples += it->sample_count;
}
return num_samples;
}
} // namespace mp4
} // namespace media