Saving a streaming video / presentation

Ever wondered to to save those streaming videos from Youtube, Metacafe, InfoQ, and so many others? I always wanted to save those streams, so that I could watch them again and again even without an Internet connection.

I am a faithful Firefox user, and one of its wonderful plugin - DownloadHelper has helped me for a long time to capture and save Youtube videos as flash video files on my local hard disk. That was quite helpful. But I always wanted to save those InfoQ videos as well, but unfortunately, DownloadHelper did not provide support for InfoQ (among others).

It was only recently, that I used the conversion feature of DownloadHelper, in which I was converting one of those Youtube videos to be converted to wmv format. I noticed, that the conversion started only after the whole of the video stream was played on my browser. And I could readily guess, that the conversion must be using one of the libraries on my machine. So I looked at the process to find that it was using ffmpeg command to do this job. I also noticed, that actually every video was buffered to the /tmp on my Ubuntu. The filename I could see was something like FlashVOZFnS.

This was a great news, because this was applicable even to InfoQ videos. Naturally, if a movie plays on your machine, it must be stored somewhere before being played on your browser. So now if you want to save your next streaming video, just identify where in your system does the flash player saves its movie temporarily before being played on your browser, and save that file to your videos folder, and possibly give it a .flv extension too.

Note: 

1. As soon as you close the tab containing the video, the temporary file is discarded.
2. Not all videos may be fully buffered before playing. Very long videos and webcasts may not be fully buffered.
   

Converting flash movies to other format (Linux)

And now if you also want to convert it into other formats, its very easy in Linux with the following commands:
FLV to WMV: 
ffmpeg -i /home/thomas/Desktop/infoq.flv -y -v 0 -acodec wmav1 -b 1000kbps -f asf -vcodec wmv1 /home/thomas/Desktop/infoq.wmv

FLV to MPG:
ffmpeg -i /home/thomas/dwhelper/Desktop/infoq.flv -y -v 0 -f asf -vcodec mpeg4 /home/thomas/Desktop/infoq.mpg

There are so many other options with this command, even up to video capturing your screen, but I am not very expert at those. So I leave it to you to experiment with those options.

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Update

I could notice that actually DownloadHelper can download InfoQ videos, but just that you should have only this one tab containing any video to download. In other words, if you have multiple tabs with video contents, DownloadHelper seems to get confused, so you may not actually get a download link help. Also, getting the Slides on InfoQ is also easy. If you are a good developer, just see the source code of the page, and you will understand. Right now I see those videos and slides at my ease stored on my hard disk.

Configuring log4j with XML in OSGi

Sometime back, I had to make perf4j work on OSGi. It required log4j as the logging library and purely demanded log4j.xml (it would not take the .properties file since the configuration must attach downstream appenders). I assumed that it should be simple, but unfortunately it was not. In the rest of this post, I describe how I could get around this, and used log4j.xml to configure log4j logging in OSGi.