Module: TorchCodec::Core

Defined in:
lib/torchcodec/core/metadata.rb

Class Method Summary collapse

Class Method Details

._get_optional_par_fraction(stream_dict) ⇒ Object 



3
4
5
6
7
8
9
10
11
12
 
# File 'lib/torchcodec/core/metadata.rb', line 3

def self._get_optional_par_fraction(stream_dict)
  begin
    Rational(
      stream_dict.fetch("sampleAspectRatioNum"),
      stream_dict.fetch("sampleAspectRatioDen")
    )
  rescue KeyError
    nil
  end
end

.get_container_metadata(decoder) ⇒ Object 



14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
 
# File 'lib/torchcodec/core/metadata.rb', line 14

def self.get_container_metadata(decoder)
  container_dict = JSON.parse(_get_container_json_metadata(decoder))
  streams_metadata = []

  container_dict["numStreams"].times do |stream_index|
    stream_dict = JSON.parse(_get_stream_json_metadata(decoder, stream_index))
    common_meta = {
      duration_seconds_from_header: stream_dict["durationSecondsFromHeader"],
      duration_seconds: stream_dict["durationSeconds"],
      bit_rate: stream_dict["bitRate"],
      begin_stream_seconds_from_header: stream_dict["beginStreamSecondsFromHeader"],
      begin_stream_seconds: stream_dict["beginStreamSeconds"],
      codec: stream_dict["codec"],
      stream_index: stream_index
    }
    if stream_dict["mediaType"] == "video"
      streams_metadata << {
        begin_stream_seconds_from_content: stream_dict["beginStreamSecondsFromContent"],
        end_stream_seconds_from_content: stream_dict["endStreamSecondsFromContent"],
        end_stream_seconds: stream_dict["endStreamSeconds"],
        num_frames: stream_dict["numFrames"],
        average_fps: stream_dict["averageFps"],
        width: stream_dict["width"],
        height: stream_dict["height"],
        num_frames_from_header: stream_dict["numFramesFromHeader"],
        num_frames_from_content: stream_dict["numFramesFromContent"],
        average_fps_from_header: stream_dict["averageFpsFromHeader"],
        pixel_aspect_ratio: _get_optional_par_fraction(stream_dict),
        **common_meta
      }
    elsif stream_dict["mediaType"] == "audio"
      streams_metadata << {
        sample_rate: stream_dict["sampleRate"],
        num_channels: stream_dict["numChannels"],
        sample_format: stream_dict["sampleFormat"],
        **common_meta
      }
    else
      # This is neither a video nor audio stream. Could be e.g. subtitles.
      # We still need to add a dummy entry so that len(streams_metadata)
      # is consistent with the number of streams.
      streams_metadata << common_meta
    end
  end

  {
    duration_seconds_from_header: container_dict["durationSecondsFromHeader"],
    bit_rate_from_header: container_dict["bitRate"],
    best_video_stream_index: container_dict["bestVideoStreamIndex"],
    best_audio_stream_index: container_dict["bestAudioStreamIndex"],
    streams: streams_metadata
  }
end