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

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// 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_TEXT_HANDLER_H_
#define PACKAGER_MEDIA_FORMATS_WEBVTT_WEBVTT_TEXT_HANDLER_H_
#include <stdint.h>
#include <vector>
#include "packager/media/base/media_handler.h"
#include "packager/media/base/muxer_options.h"
#include "packager/media/event/muxer_listener.h"
namespace shaka {
namespace media {
// WebVttOutputHandler is the base class for all WebVtt text output handlers.
// It handles taking in the samples and writing the text out, but relies on
// sub classes to handle the logic of when and where to write the information.
class WebVttOutputHandler : public MediaHandler {
public:
WebVttOutputHandler() = default;
virtual ~WebVttOutputHandler() = default;
protected:
virtual Status OnStreamInfo(const StreamInfo& info) = 0;
virtual Status OnSegmentInfo(const SegmentInfo& info) = 0;
virtual Status OnTextSample(const TextSample& sample) = 0;
virtual Status OnStreamEnd() = 0;
// Top level functions for output. These functions should be used by
// subclasses to write to files.
void WriteCue(const std::string& id,
uint64_t start,
uint64_t end,
const std::string& settings,
const std::string& payload);
// Writes the current state of the current segment to disk. This will
// reset the internal state and set it up for the next segment.
Status WriteSegmentToFile(const std::string& filename);
private:
WebVttOutputHandler(const WebVttOutputHandler&) = delete;
WebVttOutputHandler& operator=(const WebVttOutputHandler&) = delete;
Status InitializeInternal() override;
Status Process(std::unique_ptr<StreamData> stream_data) override;
Status OnFlushRequest(size_t input_stream_index) override;
// A buffer of characters waiting to be written to a file.
std::string buffer_;
};
// This WebVttt output handler should only be used when the source WebVTT
// content needs to be segmented across multiple files.
class WebVttSegmentedOutputHandler : public WebVttOutputHandler {
public:
WebVttSegmentedOutputHandler(const MuxerOptions& muxer_options,
std::unique_ptr<MuxerListener> muxer_listener);
private:
Status OnStreamInfo(const StreamInfo& info) override;
Status OnSegmentInfo(const SegmentInfo& info) override;
Status OnTextSample(const TextSample& sample) override;
Status OnStreamEnd() override;
Status OnSegmentEnded();
void GoToNextSegment(uint64_t start_time_ms);
const MuxerOptions muxer_options_;
std::unique_ptr<MuxerListener> muxer_listener_;
// Sum together all segment durations so we know how long the stream is.
uint64_t total_duration_ms_ = 0;
uint32_t segment_index_ = 0;
};
} // namespace media
} // namespace shaka
#endif // PACKAGER_MEDIA_FORMATS_WEBVTT_WEBVTT_TEXT_HANDLER_H_