I think I see what you mean. Perhaps it's a result of the continual
reinterpolating of the spectrogram graphics to achieve the non integer
horizontal movement. If so then it could be fixed by adjusting the horizontal
scale of the image a bit.
I decided not to use that method because the correct scale depends on the
number of frames in the movie. I.e. the scale is determined by the length of
the clip, and will therefore have to be different for different recordings. It
also requires manual adjustment of the generating script each time, and I'd
like to automate it all.
From: On
Behalf Of rock_scallop
Sent: Monday, 14 January 2013 5:20 AM
To:
Subject: [Nature Recordists] Re: More on scrolling spectrograms
Thanks, Peter. I do not mean jerky like fits and starts, but rather a slightly
uneven flow like a bicycle wheel with somewhat worn bearings. It may just be
from the youtube. Anyway, it is pretty darn cool.
John Hartog
rockacallop.org
--- In
<naturerecordists%40yahoogroups.com>,
Peter Shute wrote:
>
> I ended up using sox, the command line audio program, to dump the image. Not
> quite as good as some of the other programs I tried, but it has the advantage
> that I have full control of the scales, and I can now probably automate the
> whole process.
>
> It will only create an image a maximum of 5000 pixels wide (3 minutes at the
> scale I chose), so I had to join dozens of them together, but that can be
> automated too. The program authors have agreed to increase it to 200,000
> pixels in the next release, probably sometime this year. All the other
> programs I tried had some sort of limit, generally less than half an hour,
> after which they'd crash or include random data in the image, or refuse to
> dump. I only looked at free programs.
>
> What do you mean by jerky? The scrolling, or the audio itself? Either way,
> you'd think it would be better when it's not being streamed from the
> Internet. It's also been twice compressed - once by me to get it small enough
> to upload, and once by YouTube in unknown ways.
>
> My main incentive for doing this was to make spectrograms of my recordings
> more accessible to birders who don't know how to create their own. I find
> that if I ask for expert advice about the id of a bird calling softly in the
> background of a dawn chorus, for example, people often can't understand which
> bit I mean. This way I can draw labels on the spectrogram image before I turn
> it into a movie, and hopefully it'll assist them, at least with the timing of
> the call.
>
> Another idea I had recently was to put movies of new recordings onto my iPad.
> That would let me review them more efficiently, in bed, on the train, etc,
> than just listening to audio. I wish I could make notes directly on the movie
> frames.
>
> Sent from my iPad
>
> On 13/01/2013, at 3:31 PM, "rock_scallop" > wrote:
>
>
>
> Hi Peter,
> What do you mean by "dumped spectrogram images?" What are you using to
> generate the images to be dumped?
> Nice sounds. I played the long one for a little while, a wee bit jerky but I
> think it's acceptable for an online viewing. Would it play smoother as a
> download or DVD video?
>
> John Hartog
> rockscallop.org
>
> --- In
> <naturerecordists%40yahoogroups.com> ,
> "Marc Myers" wrote:
> >
> > There are shortcomings to Acousmographe but I've used it for some time. My
> > original solution was to convert the Flash movie to another format with SWF
> > & FLV toolkit. Lately I've been using Premiere CS5, I import the FLV file,
> > then add the original audio. Then output to whatever file format I wish.
> > The advantage of Acousmographe is one can annotate.
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