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CPL MainMarkers track IntrinsicDuration value #10

Open cfadamp opened 5 months ago

cfadamp commented 5 months ago

We received mixed request regarding the value of the MainMarkers track's IntrinsicDuration value. One group suggest that this value shall be one frame larger than the last Marker's Offset (a lot of mastering software use with this method).

<MainMarkers>
          <Id>urn:uuid:3aba1841-a4dd-41b4-8159-77dc49cda422</Id>
          <EditRate>24 1</EditRate>
          <IntrinsicDuration>2</IntrinsicDuration>
          <MarkerList>
            <Marker>
              <Label>FFOC</Label>
              <AnnotationText>First Frame of Composition</AnnotationText>
              <Offset>1</Offset>
            </Marker>
          </MarkerList>
        </MainMarkers>

The other group suggest that the tracks inside a reel must be homogeneous, thus the IntrinsicDuration of the MainMarkers track should be equal to the Duration of the Picture track.

<MainMarkers>
          <Id>urn:uuid:d638e663-08f4-4000-807b-a216e89c9f51</Id>
          <EditRate>24 1</EditRate>
          <IntrinsicDuration>3575</IntrinsicDuration>
          <MarkerList>
            <Marker>
              <Label>FFOC</Label>
              <AnnotationText>First Frame of Composition</AnnotationText>
              <Offset>1</Offset>
            </Marker>
          </MarkerList>
        </MainMarkers>

Could you clarify which value should be used?

SteveLLamb commented 1 week ago

For discussion here https://github.com/SMPTE/st429-7/issues/6