75 lines
2.8 KiB
C++
75 lines
2.8 KiB
C++
// Copyright 2017 Google LLC. 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_BASE_TRICK_PLAY_HANDLER_H_
|
|
#define PACKAGER_MEDIA_BASE_TRICK_PLAY_HANDLER_H_
|
|
|
|
#include <list>
|
|
|
|
#include <packager/media/base/media_handler.h>
|
|
|
|
namespace shaka {
|
|
namespace media {
|
|
|
|
class VideoStreamInfo;
|
|
|
|
/// TrickPlayHandler is a single-input single-output media handler. It takes
|
|
/// the input stream and converts it to a trick play stream by limiting which
|
|
/// samples get passed downstream.
|
|
// The stream data in trick play streams are not simple duplicates. Some
|
|
// information get changed (e.g. VideoStreamInfo.trick_play_factor).
|
|
class TrickPlayHandler : public MediaHandler {
|
|
public:
|
|
explicit TrickPlayHandler(uint32_t factor);
|
|
|
|
private:
|
|
TrickPlayHandler(const TrickPlayHandler&) = delete;
|
|
TrickPlayHandler& operator=(const TrickPlayHandler&) = delete;
|
|
|
|
Status InitializeInternal() override;
|
|
Status Process(std::unique_ptr<StreamData> stream_data) override;
|
|
Status OnFlushRequest(size_t input_stream_index) override;
|
|
|
|
Status OnStreamInfo(const StreamInfo& info);
|
|
Status OnSegmentInfo(std::shared_ptr<const SegmentInfo> info);
|
|
Status OnMediaSample(const MediaSample& sample);
|
|
Status OnTrickFrame(const MediaSample& sample);
|
|
|
|
const uint32_t factor_;
|
|
|
|
uint64_t total_frames_ = 0;
|
|
uint64_t total_key_frames_ = 0;
|
|
uint64_t total_trick_frames_ = 0;
|
|
|
|
// We cannot just send video info through as we need to calculate the play
|
|
// rate using the first two trick play frames. This reference should only be
|
|
// used to update the play back rate before video info is sent downstream.
|
|
// After getting sent downstream, this should never be used.
|
|
std::shared_ptr<VideoStreamInfo> video_info_;
|
|
|
|
// We need to track the segment that most recently finished so that we can
|
|
// extend its duration if there are empty segments.
|
|
std::shared_ptr<SegmentInfo> previous_segment_;
|
|
|
|
// Since we are dropping frames, the time that those frames would have been
|
|
// on screen need to be added to the frame before them. Keep a reference to
|
|
// the most recent trick play frame so that we can grow its duration as we
|
|
// drop other frames.
|
|
std::shared_ptr<MediaSample> previous_trick_frame_;
|
|
|
|
// Since we cannot send messages downstream right away, keep a queue of
|
|
// messages that need to be sent down. At the start, we use this to queue
|
|
// messages until we can send out |video_info_|. To ensure messages are
|
|
// kept in order, messages are only dispatched through this queue and never
|
|
// directly.
|
|
std::list<std::unique_ptr<StreamData>> delayed_messages_;
|
|
};
|
|
|
|
} // namespace media
|
|
} // namespace shaka
|
|
|
|
#endif // PACKAGER_MEDIA_BASE_TRICK_PLAY_HANDLER_H_
|