CHDK PTP interface - page 67 - General Discussion and Assistance - CHDK Forum

CHDK PTP interface

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Re: CHDK PTP interface
« Reply #660 on: 15 / February / 2012, 09:38:34 »
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It is the only way you will get 5 fps.

as a matter of interest, I used 640x480 movie frames from a SINGLE rotating camera to create the top stereo panorama here :  http://www.stereomaker.net/panorama/panoramae.htm

Here are some technical details http://stereo.jpn.org/eng/stphmkr/help/file_27.htm

i did indeed go thru your site keenly a few months back the results are quite impressive from my point of view

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Either you need 5 fps or you do not.
The only in-between is to run in burst-shooting mode at whatever resolution you wish.
So, you can have 5 fps, 0.3 fps or something in-between.
The accumulated images can be batch-downloaded at intervals via PTP.
Bear in mind that my A620 uses MJPEG encoding for the movies, every frame is a JPG.
With the more recent MOV files, most frames are interpolated.
I would use VirtualDub to change the framerate to 5 fps, save as an image sequence and then inspect them to determine the quality loss.

i dont intend changing the frame rate in virtualdub as in any case i would be finally saving the frames. i would be saving every 6th frame that would give me the 5fps (assuming 30fps i think that the camera uses) that i want.

thankyou for your feedback - after discussing with you i think it is the way to go. also as i am using SX 130 i would be getting 1280 x 720 (or thereabouts i think) and i have done some test runs the video quality is excellent for my requirement.



Re: CHDK PTP interface
« Reply #661 on: 15 / February / 2012, 09:54:06 »

i dont intend changing the frame rate in virtualdub

Maybe you misunderstand, that in effect temporarily throws away most frames and allows you to save the remainder as an image sequence.

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i think it is the way to go. also as i am using SX 130 i would be getting 1280 x 720 (or thereabouts i think) and i have done some test runs the video quality is excellent for my requirement.

I am also interested in using a 1280x720 camera for the stereo panoramas, orientated vertically to give almost 3x the height of my 640x480 images.

Is it possible to post a full-size extracted frame somewhere ?

There may be an earlier Canon camera that supports movie size greater than 640x480 AND still uses MJPEG encoding.

If so, maybe the compression is higher.
The unknown factor is whether the quality of the extracted frame would be better than the interpolated higher-resolution one.


David

Re: CHDK PTP interface
« Reply #662 on: 16 / February / 2012, 00:38:00 »
of course i can post a full fram capture -
if you want i can also upload a small clip so that you may experiment with it.

give me a few hrs and i will post the clip and the frame

from what little i have had time to check the movie mode- the quality really blew me away. it was more than anything i had expected ( :) i had low expectation from the movie mode anyways )
« Last Edit: 16 / February / 2012, 00:40:02 by ntstatic »

Re: CHDK PTP interface
« Reply #663 on: 17 / February / 2012, 05:49:32 »
sorry about the delay ....
here are the snaps from the clip



download the clip from here..
MVI_0006.MOV

« Last Edit: 17 / February / 2012, 06:19:15 by ntstatic »


Re: CHDK PTP interface
« Reply #664 on: 17 / February / 2012, 16:58:24 »
Many thanks for that.

Yes, they are not bad at all, especially when you consider the fairly low light level.
I set framerate in VirtualDub to 3 which therefore selected 26 frames.
It would not detect that value for export as image sequence so i saved as uncompressed AVI, reloaded and saved as image sequence.

What software are you using ?


Can you lock the exposure in movie mode ?

This camera, and others, would capture 180 frames in six seconds .. sufficient for most 360 degree stereo panoramas.

Just need a 10 rpm rotator.

Something like a cordless screwdriver could rotate the camera.

Re: CHDK PTP interface
« Reply #665 on: 17 / February / 2012, 20:32:01 »
sorry about the delay ....
here are the snaps from the clip


Wa wa wa wa wa wait...  :o
What's the nature of this clip again ? Is it a PTP capture, or a movie-mode shoot, downloaded as a file from the device ?  ???

Re: CHDK PTP interface
« Reply #666 on: 18 / February / 2012, 01:16:42 »
Many thanks for that.

Yes, they are not bad at all, especially when you consider the fairly low light level.
i hope it is sufficient for your purposes. if you require i could get the thing outdoors and get you a clip. lazy is that i am, i just took the clip sitting at my table :). yes that mess is actually my office table.

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I set framerate in VirtualDub to 3 which therefore selected 26 frames.
It would not detect that value for export as image sequence so i saved as uncompressed AVI, reloaded and saved as image sequence.

What software are you using ?
for movie i use VirtualDub. for extracting the frames from the .mov files i am going to write a utility in vb6. (hoping it would not be more effort than what i am anticipating). if you are intrested i will upload it once it is done.

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Can you lock the exposure in movie mode ?
i do not think movie mode allows any setting other than White balance, Movie Quality and resolution etc. i am not sure about CHDK. dont have it at hand, will revert back.

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This camera, and others, would capture 180 frames in six seconds .. sufficient for most 360 degree stereo panoramas.

Just need a 10 rpm rotator.

Something like a cordless screwdriver could rotate the camera.

i would use a 10 rpm synchronous AC motor if left to a choice - in case AC is a problem outdoors, DC synchronous geared motors are available. here in india 10rpm A/c synchro would cost around inr 100. (around us$ 2) and dc synchronous would be approx inr 150 - 200 (us$ 3 -4)

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Wa wa wa wa wa wait...  :o
What's the nature of this clip again ? Is it a PTP capture, or a movie-mode shoot, downloaded as a file from the device ?  ???
it is not a PTP capture, just a regular capture from the camera. but PTP is perfectly capable of capturing in movie mode and downloading the clip.

Re: CHDK PTP interface
« Reply #667 on: 18 / February / 2012, 06:17:04 »
i am going to write a utility in vb6. (hoping it would not be more effort than what i am anticipating). if you are intrested i will upload it once it is done.

Yes, thanks.
If you were really clever you could write a VDub plugin but ther last time I looked at the code it was very complicated.

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in case AC is a problem outdoors

I will probably use DC motor but you have reminded me that I have a 12V DC/240C AC converter that I have not used.


You can lock the exposure on your SX130is in movie mode, see page 103 of the manual.

David
« Last Edit: 18 / February / 2012, 06:54:53 by Microfunguy »


Re: CHDK PTP interface
« Reply #668 on: 18 / February / 2012, 08:58:02 »
i am going to write a utility in vb6. (hoping it would not be more effort than what i am anticipating). if you are intrested i will upload it once it is done.

Yes, thanks.
If you were really clever you could write a VDub plugin but ther last time I looked at the code it was very complicated.
yes a plugin in VDub would be one way of doing it, but i need the end user to feel that the whole damn thing is a proper solution without patchwork. i could probably call VirtualDub in the background but still i would like to have control and know when exactly the process is completed. also i always think of a solution in VB so probably i can do it faster that way.

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Quote
in case AC is a problem outdoors

I will probably use DC motor but you have reminded me that I have a 12V DC/240C AC converter that I have not used.


You can lock the exposure on your SX130is in movie mode, see page 103 of the manual.
David
thanks will check

Re: CHDK PTP interface
« Reply #669 on: 18 / February / 2012, 10:15:48 »
i always think of a solution in VB so probably i can do it faster that way.

Are you saying a VB application can extract the frames without requiring the VDub MOV plugin and without having QuickTime installed on your PC ?

 

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