fcp xml invalid start time for clip.

[alatdneg]

Seems to be a bug in the code that calculates the start time..

start time doesn't match premiere, which is 1002

[
    {
        "OTIO_SCHEMA": "Clip.1", 
        "effects": [], 
        "markers": [], 
        "media_reference": {
            "OTIO_SCHEMA": "ExternalReference.1", 
            "available_range": {
                "OTIO_SCHEMA": "TimeRange.1", 
                "duration": {
                    "OTIO_SCHEMA": "RationalTime.1", 
                    "rate": 29.97, 
                    "value": 5744
                }, 
                "start_time": {
                    "OTIO_SCHEMA": "RationalTime.1", 
                    "rate": 29.97, 
                    "value": 500
                }
            }, 
            "name": null, 
            "target_url": "file://localhost/test.wav"
        }, 
        "metadata": {}, 
        "name": "test.wav", 
        "source_range": {
            "OTIO_SCHEMA": "TimeRange.1", 
            "duration": {
                "OTIO_SCHEMA": "RationalTime.1", 
                "rate": 60.0, 
                "value": 2246
            }, 
            "start_time": {
                "OTIO_SCHEMA": "RationalTime.1", 
                "rate": 60.0, 
                "value": 1001.001001001001
            }
        }
    }
]

clipitem id="clipitem-732" premiereChannelType="stereo">
	<masterclipid>masterclip-81</masterclipid>
	<name>hw_seq_full_mix.wav</name>
	<enabled>TRUE</enabled>
	<duration>11500</duration>
	<rate>
		<timebase>60</timebase>
		<ntsc>FALSE</ntsc>
	</rate>
	<start>0</start>
	<end>2246</end>
	<in>0</in>
	<out>2246</out>
	<pproTicksIn>0</pproTicksIn>
	<pproTicksOut>9508665600000</pproTicksOut>
	<file id="file-81">
		<name>test.wav</name>
		<pathurl>file://localhost/test.wav</pathurl>
		<rate>
			<timebase>30</timebase>
			<ntsc>TRUE</ntsc>
		</rate>
		<duration>5744</duration>
		<timecode>
			<rate>
				<timebase>30</timebase>
				<ntsc>TRUE</ntsc>
			</rate>
			<string>00;00;16;20</string>
			<frame>500</frame>
			<displayformat>DF</displayformat>
		</timecode>
		<media>
			<audio>
				<samplecharacteristics>
					<depth>16</depth>
					<samplerate>48000</samplerate>
				</samplecharacteristics>
				<channelcount>2</channelcount>
			</audio>
		</media>
	</file>
	<sourcetrack>
		<mediatype>audio</mediatype>
		<trackindex>1</trackindex>
	</sourcetrack>
</clipitem>

[alatdneg]

I'm starting to think that preimier is doing something odd here, as 1001.001001001 is valid as far as I can see.

[apetrynet]

Unless this is related to my drop-frame implementation it might have to do with the fcp_xml adapter scaling source_ranges.
source_range = otio.opentime.TimeRange( start_time=start_time.rescaled_to(item_rate), duration=otio.opentime.RationalTime(out_frame - in_frame, item_rate) )
Take a look here in the adapter code.

Perhaps @bashesenaxis might be able to answer this?

[alatdneg]

Ta, I suspect this stuff is going to be a bit tricky, it's probably easier to just get someone on ourside to fix the timeline,29.97 audio in a 60fps time line is just confusing.. as audio has no rate

[jminor]

Hmmm. Yeah, I'm not sure what the intent of the rescaled_to is in the code that @apetrynet pointed out above. @bashesenaxis can you give us a hint about what you intended with that?

[bashesenaxis]

I am not 100% sure at this point anymore what the point of that rescale was. Some thoughts below.

• Looking at the code, start_time should already be in item_rate. But perhaps because we are adding the timecode to it, this could change? Then if we force a rescale, at least we know what the rate will be in the end.
• I don`t think that xml is very aware of the different rates of the clips on a timeline. The rate is defined by the timeline.
• If you have independent clip rates and available rates, this could imply that your clip is stretched in time. At the time of writing the adapter, that was not a feature of otio and I am not entirely sure how it will behave with scaled clips.