Bill, The Cornell folks could probably answer you more definitively, but I think this is not a bug, but rather a result the way spectrograms are generated. The spectrogram comes from sampling and analyzing successive chunks of the waveform, so until enough time has gone by to encompass the initial "chunk" of the waveform there's not enough information to generate the spectrogram. You can change the delay by adjusting the spectrogram parameters, and you should be able to calculate what the delay will be as a function of those parameters, but there will always be a lag.
The lag is small enough that it won't be noticeable unless you are looking at a very short file, like an NFC. It may be that different programs make different decisions about how the spectrogram lines up with the wave form, so that the lag his masked in some programs. Hope that helps. Laura On 1/22/2015 7:40 AM, Bill Evans wrote: > When I open a short night flight call wav file in Raven, the waveform > window begins at 0 sec but the accompanying spectrogram window doesn't > begin at zero -- it begins after a few milliseconds. See attached example. > It’s not something that one would note unless they are working with > very short sound files, and perhaps wish to use such a short > spectrogram in a publication. > Anyone else notice this possible bug in Raven? > Bill Evans > -- > *NFC-L List Info:* > Welcome and Basics <http://www.northeastbirding.com/NFC_WELCOME> > Rules and Information <http://www.northeastbirding.com/NFC_RULES> > Subscribe, Configuration and Leave > <http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> > *Archives:* > The Mail Archive > <http://www.mail-archive.com/nfc-l@cornell.edu/maillist.html> > Surfbirds <http://www.surfbirds.com/birdingmail/Group/NFC-L> > BirdingOnThe.Net <http://birdingonthe.net/mailinglists/NFCL.html> > *Please submit your observations to eBird > <http://ebird.org/content/ebird/>!* > -- -- NFC-L List Info: http://www.NortheastBirding.com/NFC_WELCOME http://www.NortheastBirding.com/NFC_RULES http://www.NortheastBirding.com/NFC-L_SubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/nfc-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NFC-L 3) http://birdingonthe.net/mailinglists/NFCL.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
