Date: Sat, 8 Apr 2000 12:32:18 -0400 From: Walter Scott <[EMAIL PROTECTED]> Subject: RealAudio For DOS Previously, I was asked whether there is software available for DOS which might play RealAudio. Answering this question is a bit difficult. The bottom line, as nearly as I can tell, is that it might be a losing battle to try for RealAudio in DOS. Real Networks -- the folks who created and control RealAudio -- will provide support for Windows alone. It seems as though any progress with RealAudio in DOS has been through reverse engineering of RealAudio file formats. Note that this is a perception. I don't know it for certain and suspect I could be wrong; it's hard to know for certain what's what on this issue. Apparently, Real Networks protects its RealAudio file formats and has forged a relationship with providers of RealAudio and RealVideo content to insure goals are achieved consistent with Real Networks' business priorities and the copyright concerns of providers. Thus, whether you can ultimately download, keep, and play back material you'd be interested to hear is an important issue which is not entirely in your control. In fact, this is not within the control of many who have and use the latest version of RealPlayer from Real Networks. Where radio and television stations are concerned: they want to be certain that content won't be downloaded and distributed across the INTERNET to various sites where the station does not want such content to reside. Accordingly, server software seems designed to determine whether the RealPlayer is being used to obtain and listen to the LATEST format of RealAudio. If not, then access is blocked; the server just won't give you the content. Ergo, the provider can be certain content won't be used or re-used except by the provider's permission. Radio and TV stations are VERY picky about this! Some providers allow completely unrestricted access to their RealAudio with the option to, as Real Networks' software refers to it, "record" content. There are FEW content providers on the INTERNET that do this, and PROBABLY even fewer who have content most folks would care to download and keep on their hard disk. This situation is partly why the MP3 revolution has been picking up steam. With this in mind, it appears to be unlikely anyone will be hot to build a RealAudio player for DOS. One can, however, find material on the INTERNET created in older RealAudio formats that can be downloaded and retained on your hard disk. Is it worth keeping? That is for the listener to decide. Is it worth supporting from a programmer's perspective? It doesn't seem so. But, there ARE options. Here is one such option: --------------------------------------------------------------------------- http://members.tripod.com/~ladsoft/ra.htm LADsoft Real Audio Page Real audio is all the rage on the internet; unfortunately they don't support certain platforms like MSDOS. On the up side I was able to find an amiga page that has sources for a real-audio decoder on it. But on the down side that is for an older version of real audio. Still, it works very well for those files it will decode... Decoding into a flat file of 16-bit samples at approximately an 8KHZ rate. However, after some talking to the powers that be it turned out there is a (largely unknown) decoder for the type of real-audio file that has been seeing the most popularity of late. I've gotten hold of that and it works extremely well as well on the files it was designed for. Unfortunately it appears that this version only works for a subset of the RA4 files; there are things that can be done in the headers to defeat it. But there is a third type of RA file which is actually called a real-media file. It is essentially an encapsulation of the second type of RA file, and I plan to support it a little later on. I'm probably going to make one utility that will do all three types of files... for now all you will find on this site is source code. Later when I get my act together and have time to clean some of this up I will post executables. Good news is these programs compile on both a 16-bit and 32-bit compiler so you should be able to compile it any way you want. Getting back to 16-bits was a real hassle in this case because of compiler differences... but you want to use a 32-bit compiler if you can, the stuff runs faster. Finally, if you have a sound blaster I have a play utility you can use to play this stuff, sources are on my SOUND page. I will include an executable for that as well as soon as I do executables. Unfortunately I don't support anything other than sound blaster, you have to find another player if you don't have a sound blaster card. Maybe MIKMOD will do it, I don't know. Here are links to the two source codes I have. Bear in mind that these RA decoders were not written by me; as far as I know it is in the public domain which means you can basically do as you please with it. 14.4Khz decoder (old style): http://members.tripod.com/~ladsoft/ra/ra144.txt 28.8Khz decoder (new style): http://members.tripod.com/~ladsoft/ra/ra288.txt Here is a link to a generic decoder (for MSDOS) which will identify and decode either of the above two formats; or tell you what kind of format you have that it can not decode. This is executables for both a decoder and a player; the player is sound-blaster specific so you may need to find another player if you do not have a sound blaster. Generic decoder executables: http://members.tripod.com/~ladsoft/ra/rax.zip My current link to good sound files in both formats is: GoldTooth Sound Clips: HTTP://www.goldtoothdisplay.com/avpage.shtml Bear in mind if you aren't using a browser with a real-audio plug-in, this site will actually send you a .RAM file. Type the .RAM file out and it gives you a URL where you can get the associated sound file. --------------------------------------------------------------------------- ******************************************************** To unsubscribe from this list, send a message to [EMAIL PROTECTED] with the single word Unsubscribe as the subject. You MUST use the same address with which you subscribed! ********************************************************
