shaka-packager/packager/media/formats/webvtt/webvtt_segmenter.h

72 lines
2.1 KiB
C++

// Copyright 2017 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
#ifndef PACKAGER_MEDIA_FORMATS_WEBVTT_WEBVTT_SEGMENTER_H_
#define PACKAGER_MEDIA_FORMATS_WEBVTT_WEBVTT_SEGMENTER_H_
#include <stdint.h>
#include <list>
#include <queue>
#include "packager/media/base/media_handler.h"
#include "packager/status.h"
namespace shaka {
namespace media {
// Because a text sample can be in multiple segments, this struct
// allows us to associate a segment with a sample. This allows us
// to easily sort samples base on segment then time.
struct WebVttSegmentedTextSample {
uint64_t segment = 0;
std::shared_ptr<const TextSample> sample;
};
class WebVttSegmentedTextSampleCompare {
public:
bool operator()(const WebVttSegmentedTextSample& left,
const WebVttSegmentedTextSample& right) const {
// If the samples are in the same segment, then the start time is the
// only way to order the two segments.
if (left.segment == right.segment) {
return left.sample->start_time() > right.sample->start_time();
}
// Time will not matter as the samples are not in the same segment.
return left.segment > right.segment;
}
};
class WebVttSegmenter : public MediaHandler {
public:
explicit WebVttSegmenter(uint64_t segment_duration_ms);
protected:
Status Process(std::unique_ptr<StreamData> stream_data) override;
Status OnFlushRequest(size_t input_stream_index) override;
private:
WebVttSegmenter(const WebVttSegmenter&) = delete;
WebVttSegmenter& operator=(const WebVttSegmenter&) = delete;
Status InitializeInternal() override;
Status OnTextSample(std::shared_ptr<const TextSample> sample);
Status OnSegmentEnd();
uint64_t segment_duration_ms_;
std::priority_queue<WebVttSegmentedTextSample,
std::vector<WebVttSegmentedTextSample>,
WebVttSegmentedTextSampleCompare>
samples_;
};
} // namespace media
} // namespace shaka
#endif // PACKAGER_MEDIA_FORMATS_WEBVTT_WEBVTT_SEGMENTER_H_