"The Linux Gazette...making Linux just a little more fun!"

The Lost Art of Helper Apps

From Josh Stewart on Mon, 12 Jul 1999

I don't like streaming video because it looks and sounds bad. Do you know a wayfor saving a real video to my hard disk and I don't care how big it because I have a fast connection. Example: How would I save this file: pnm://209.196.146.50:7090/air1/realmedia/myfriend.rm

I've never use streaming audio or video over the Internet. So, I'll only be guessing at things a bit here.

The URL you've give would be typical of one that would invoke a "Helper Application" in a traditional web browser.

Helper Applications existed before Netscape "plugins" and Java, JavaScript, and frames and CSS and most of the buzz/hype stuff that the big web sites and software companies are pushing unto the web. The idea was simple: URLs start with a format specifier: ftp://, http://, telnet://, gopher:// etc. The only ones you usually see these days are http:// and ftp:// which are handled directly by your web browser. (Gopher is still supported by most web browsers, too, from which I've heard. I haven't seen a gopher site in so long I have no way to test this).

For any service that the browser doesn't handle itself, it consults a list of "helper apps" These bind the service prefix to a program (such as the real audio player, or whatever).

So the question is, can you replace your realmedia player with a program that speaks the correct protocol to the realmedia server on the far end and then writes that out the the disk instead of out to your sound card and video subsystem.

I don't know. I don't know what protocol they are using to stream the data to you.

Another question might be: Is there a utility for Linux that could allow you capture the output to your video/sound through some sort of "loopback" arrangement. (Guess what! I don't know the answer to that either).

However they are interesting questions and I'll pose them as "stumpers of the month"

Finally another question comes to mind --- is the poor quality of this material (as you're experiencing) due to the delivery mechanism (the fact that it's streaming over a presumably low bandwidth connectin as you're viewing it, or is it due to some other factor? Will looping it out to your disk improve it?

My guess is that saving it to disk (without improving the delivery bandwidth by which it gets to your system) probably won't help. I'd guess that the server is doing some scaling of the image/sound quality on the fly, as it delivers it to you and in response to you speed and latency of your connection.

Of course it would make sense if your friends (the content providers) simply provided you with access to MPEG videos and MP3 files via FTP or HTTP. Then you'd download (at whatever speed, who cares) and playback at your leisure.

But that would probably be too easy among your friends, and is probably not an option at many of the "new media" sites on the modern stupor hypeway.

Copyright © 1999, James T. Dennis
Published in The Linux Gazette Issue 44 August 1999

HTML transformation by Heather Stern of Starshine Techinical Services, http://www.starshine.org/

			1	4	7	9
			11	12	14	17
18	19	20	21	24	25	26
28	29	30	31	32	33	34
35	36	37	38	39	40	41
42	43	44	45	46	47	48