media/filters/hls_live_rendition.h

   1 // Copyright 2023 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_FILTERS_HLS_LIVE_RENDITION_H_
   6 #define MEDIA_FILTERS_HLS_LIVE_RENDITION_H_
   7
   8 #include <queue>
   9
  10 #include "base/containers/queue.h"
  11 #include "base/moving_window.h"
  12 #include "media/filters/hls_rendition.h"
  13
  14 namespace media {
  15
  16 // Represents the playback logic for livestreams.
  17 class MEDIA_EXPORT HlsLiveRendition : public HlsRendition {
  18  public:
  19   ~HlsLiveRendition() override;
  20   HlsLiveRendition(ManifestDemuxerEngineHost* engine_host,
  21                    HlsRenditionHost* rendition_host,
  22                    std::string role,
  23                    scoped_refptr<hls::MediaPlaylist> playlist,
  24                    GURL media_playlist_uri);
  25
  26   // `HlsRendition` implementation
  27   absl::optional<base::TimeDelta> GetDuration() override;
  28   void CheckState(base::TimeDelta media_time,
  29                   double playback_rate,
  30                   ManifestDemuxer::DelayCallback time_remaining_cb) override;
  31   ManifestDemuxer::SeekResponse Seek(base::TimeDelta seek_time) override;
  32   void StartWaitingForSeek() override;
  33   void Stop() override;
  34
  35  private:
  36   base::TimeDelta GetForwardBufferSize() const;
  37
  38   // Segment fetching and appending.
  39   void LoadSegment(const hls::MediaSegment& segment, base::OnceClosure cb);
  40   void FetchMoreDataFromPendingStream(base::OnceClosure cb);
  41   void OnSegmentData(base::OnceClosure cb,
  42                      base::TimeTicks net_req_start,
  43                      HlsDataSourceProvider::ReadResult result);
  44
  45   // Manifest fetching.
  46   void AppendSegments(hls::MediaPlaylist* playlist);
  47   void MaybeFetchManifestUpdates(base::TimeDelta delay,
  48                                  ManifestDemuxer::DelayCallback cb);
  49   void FetchManifestUpdates(base::TimeDelta delay,
  50                             ManifestDemuxer::DelayCallback cb);
  51   void OnManifestUpdates(base::TimeTicks download_start_time,
  52                          base::TimeDelta delay_time,
  53                          ManifestDemuxer::DelayCallback cb,
  54                          HlsDataSourceProvider::ReadResult result);
  55   void ClearOldData(base::TimeDelta time);
  56   void ResetForPause();
  57   void ContinuePartialFetching(base::OnceClosure cb);
  58
  59   // `ManifestDemuxerEngineHost` owns the `HlsRenditionHost` which in
  60   // turn owns |this|, so it's safe to keep these as raw ptrs. |host_| is needed
  61   // to access the chunk demuxer, and |engine_| is needed to make network
  62   // requests.
  63   raw_ptr<ManifestDemuxerEngineHost> engine_host_;
  64   raw_ptr<HlsRenditionHost> rendition_host_;
  65
  66   // The chunk demuxer role for this rendition.
  67   std::string role_;
  68
  69   // The current playlist. Needs to be updated periodically.
  70   GURL media_playlist_uri_;
  71
  72   // A queue of segments.
  73   base::queue<scoped_refptr<hls::MediaSegment>> segments_;
  74
  75   // The parser offset timestamp for this stream.
  76   base::TimeDelta parse_offset_;
  77   base::TimeDelta parse_end_ = base::Seconds(0);
  78
  79   // Keep state for reloading playlists.
  80   base::TimeTicks last_download_time_;
  81   hls::types::DecimalInteger last_sequence_number_ = 0;
  82   hls::types::DecimalInteger first_sequence_number_ = 0;
  83
  84   // Manifests should declare an upper limit on the length of segments.
  85   base::TimeDelta segment_duration_upper_limit_;
  86
  87   // If this is set, then use it to get more data. Otherwise, fetch another
  88   // segment.
  89   std::unique_ptr<HlsDataSourceStream> partial_stream_;
  90
  91   // Record the time it takes to download content.
  92   base::MovingAverage<base::TimeDelta, base::TimeDelta> fetch_time_{32};
  93
  94   bool has_ever_played_ = false;
  95   bool require_seek_after_unpause_ = false;
  96   bool is_stopped_for_shutdown_ = false;
  97
  98   SEQUENCE_CHECKER(sequence_checker_);
  99
 100   base::WeakPtrFactory<HlsLiveRendition> weak_factory_{this};
 101 };
 102
 103 }  // namespace media
 104
 105 #endif  // MEDIA_FILTERS_HLS_LIVE_RENDITION_H_