file duration

[mpage]

Hello,
is it possible to compute with an Xpath query (or using any other XML tool) the total duration of a .aup file ?
Best regards,
Michel

[steve]

Not easily.
Audacity Projects may contain multiple audio clips in the same track, each with a start position offset.
You would need to identify the final audio clip (<sequence> ... </sequence>) in a track and its offset value, then add together the offset time with the sequence "numsamples" converted to seconds, then repeat for each track in the project and output the largest value.

[mpage]

Thanks for your answer Steve.
The files I deal with contain only one audio clip, so it should make the things simpler. However , I have difficulties to figure out how to perform the computation you propose.
Can you please give an example on the file below (the actual duration is around 71s) ?
Best
M.

Not easily.
Audacity Projects may contain multiple audio clips in the same track, each with a start position offset.
You would need to identify the final audio clip (<sequence> ... </sequence>) in a track and its offset value, then add together the offset time with the sequence "numsamples" converted to seconds, then repeat for each track in the project and output the largest value.

Code: Select all

<?xml version="1.0" standalone="no"?>
<!DOCTYPE project PUBLIC "-//audacityproject-1.3.0//DTD//EN" "http://audacityteam.org/xml/audacityproject-1.3.0.dtd">
<project xmlns="http://audacityteam.org/xml/" projname="020_data" version="1.3.0" audacityversion="1.3.13-beta" sel0="28.1890249433" sel1="28.1890249433" vpos="0" h="25.0311111111" zoom="86.1328125000" rate="44100.0">
	<tags/>
	<wavetrack name="Mixer" channel="2" linked="0" mute="0" solo="0" height="150" minimized="0" rate="44100" gain="1.0" pan="0.0">
		<waveclip offset="0.00000000">
			<sequence maxsamples="262144" sampleformat="262159" numsamples="3150747">
				<waveblock start="0">
					<simpleblockfile filename="e00007fe.au" len="262144" min="-0.216187" max="0.250671" rms="0.043167"/>
				</waveblock>
				<waveblock start="262144">
					<simpleblockfile filename="e0000661.au" len="262144" min="-0.186707" max="0.284424" rms="0.057777"/>
				</waveblock>
				<waveblock start="524288">
					<simpleblockfile filename="e0000730.au" len="262144" min="-0.188629" max="0.315247" rms="0.049921"/>
				</waveblock>
				<waveblock start="786432">
					<simpleblockfile filename="e000080f.au" len="262144" min="-0.315643" max="0.349243" rms="0.050288"/>
				</waveblock>
				<waveblock start="1048576">
					<simpleblockfile filename="e0000de9.au" len="262144" min="-0.243683" max="0.396942" rms="0.058242"/>
				</waveblock>
				<waveblock start="1310720">
					<simpleblockfile filename="e00003db.au" len="262144" min="-0.212891" max="0.338654" rms="0.05351"/>
				</waveblock>
				<waveblock start="1572864">
					<simpleblockfile filename="e00000d2.au" len="262144" min="-0.279816" max="0.368225" rms="0.058814"/>
				</waveblock>
				<waveblock start="1835008">
					<simpleblockfile filename="e00005a2.au" len="262144" min="-0.248749" max="0.283569" rms="0.051571"/>
				</waveblock>
				<waveblock start="2097152">
					<simpleblockfile filename="e00003d1.au" len="262144" min="-0.236389" max="0.297821" rms="0.059904"/>
				</waveblock>
				<waveblock start="2359296">
					<simpleblockfile filename="e0000c2b.au" len="262144" min="-0.240967" max="0.298462" rms="0.048832"/>
				</waveblock>
				<waveblock start="2621440">
					<simpleblockfile filename="e0000815.au" len="262144" min="-0.221466" max="0.321503" rms="0.04221"/>
				</waveblock>
				<waveblock start="2883584">
					<simpleblockfile filename="e0000467.au" len="262144" min="-0.224884" max="0.252655" rms="0.044508"/>
				</waveblock>
				<waveblock start="3145728">
					<simpleblockfile filename="e0000a5d.au" len="5019" min="-0.00824" max="0.006683" rms="0.000828"/>
				</waveblock>
			</sequence>
			<envelope numpoints="0"/>
		</waveclip>
	</wavetrack>
</project>

[steve]

Here's the relevant part of the file:

Code: Select all

   <wavetrack name="Mixer" channel="2" linked="0" mute="0" solo="0" height="150" minimized="0" rate="44100" gain="1.0" pan="0.0">
      <waveclip offset="0.00000000">
         <sequence maxsamples="262144" sampleformat="262159" numsamples="3150747">

The sample rate is 44100 Hz.
The offset is 0.00000000
The number of samples is 3150747

To calculate the length:

offset + (numsamples / sample rate)
0.000000 + (3150747 / 44100)
= 71.445510204 seconds.

[mpage]

Great help, Steve !
Thanks a lot.
Michel

Here's the relevant part of the file:

Code: Select all

   <wavetrack name="Mixer" channel="2" linked="0" mute="0" solo="0" height="150" minimized="0" rate="44100" gain="1.0" pan="0.0">
      <waveclip offset="0.00000000">
         <sequence maxsamples="262144" sampleformat="262159" numsamples="3150747">

The sample rate is 44100 Hz.
The offset is 0.00000000
The number of samples is 3150747

To calculate the length:

offset + (numsamples / sample rate)
0.000000 + (3150747 / 44100)
= 71.445510204 seconds.