Attachment_fu

Rails
#1

Hello,
I have a functionality where i need to upload an image, So for that i am
using attachment_fu + acts_as_state_machine,. and every thing is
working
fine. But now from the view front i want to display as an thumbnail
image
just like youtube but the problem is that how do i crop a image from a
video?

Thanks for any help

Thanks
Abhis

#2

Abhishek shukla wrote:

Hello,
I have a functionality where i need to upload an image, So for that i am
using attachment_fu + acts_as_state_machine,. and every thing is
working
fine. But now from the view front i want to display as an thumbnail
image
just like youtube but the problem is that how do i crop a image from a
video?

Is your question on actually getting a frame from a video file, or
cropping an image?

As far as grabbing a frame that might depend on what video format you’re
using. For example QuickTime provides methods for getting/setting a
poster frame. So from the Quicktime API you would use a message to
QTMovie:

  • (NSImage *)posterImage.

In case no posterImage has been set then you could fall back to getting
some other frame using the message:

  • (NSImage *)frameImageAtTime:(QTTme)time

Now, obviously that’s the internals of QuickTime, but the point I’m
making is that I’m not sure that attachement_fu itself is going to help
you. I’m sure there is probably an open source tool that can provide
access to these features.

Maybe ffmpeg would help:
http://ffmpeg.org/

#3

Robert W. wrote:

Maybe ffmpeg would help:
http://ffmpeg.org/

An excerpt from the ffmpeg docs:

For extracting images from a video:

ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg

This will extract one video frame per second from the video and will
output them in files named foo-001.jpeg',foo-002.jpeg’, etc. Images
will be rescaled to fit the new WxH values.

If you want to extract just a limited number of frames, you can use the
above command in combination with the -vframes or -t option, or in
combination with -ss to start extracting from a certain point in time.
…
…
-ss position' Seek to given time position in seconds. hh:mm:ss[.xxx] syntax is also supported. ... ...-vframes number’
Set the number of video frames to record.

This looks to me like it should work well for your needs.

#4

Thanks robert for sharing the ideas will defiantly implement it.

On Thu, Sep 24, 2009 at 8:54 PM, Robert W. <