Look up the Fraunhofer reference implementation, also check out BladeEnc (both are mp3 encoders, don't try to learn decoding until you understand encoding), and goto http://www.MP3.com/ and look for open source implementations of the mp3 decoding algorithm. Critical parts of the algorithm are patented by 2 or 3 different companies. You can't implement the algorithm without treading on their patents, and thus must pay a royalty to them if you plan on distributing it (commercially or otherwise). You might try tooking into Ogg Vorbis, an open source encoding which is almost mature. It features a higher compression rate with better sound quality, and is not hampered by patents. The algorithms are about as difficult to implement on any platform as the new MP4 spec. http://www.xiph.org/ogg/vorbis/ As far as speech encoding, there are literally tons of other compression algortihms out there which are as good as mp3 with much a MUCH easier transform (that can be handled by a PIC). Obviously MP3 has to account for a much larger bandwidth than speech needs, and it would be overkill to implement a full MP3 solution for 3kHz of sound infomation. Whether you can or cannot do it on a PIC, please, go ahead and try. Many people thought TCP/IP couldn't be done on a PIC just a few short years ago, which was only because said detracters didn't know how simple tcp/ip really is if you know the PIC. I will state, as a fact, that it would NOT be worth your time trying to implement mp3 on a pic. It may be an interesting learning excersize, but decoder chips can be had for under $30 in one-offs. Unless your time is worth less than $0.50 / hr you are wasting your resources. You could work at a fast food joint for a week and make enough to have a complete MP3 testbed (controlled by a PIC, decoded by a dedicated decoder, memory stored on a HD, etc). Or you can spend several hours (minimum) reading the mp3 spec and trying to understand it, then many, many more porting existing sw to the microcontroller of your choice, or writing your own. There is a point of diminishing returns, and for this particular application that point would be where you are deciding between making one of these and making 10 million or more of them. If you were making 10 million, then it might be cost effective to do it yourself. If you are in it for the learning experience, do it on the computer, a much more flexible and powerful development and learning platform for the work you are attempting. -Adam Kyrre Aalerud wrote: > > Maaaaaaaaaaaaaan... > > If anyone knows th algorithms then please just tell him. (And me) > We know that u can't do it with a 16F84 but I think it should be up to US to figure out if we can do it at all.... > Please... If anyone have some routines for mp3 decoding thne post it! > > I on my hand want to decode a mp3 stream of only 3 kbit... With a bandwith of a probable 1-2 kHz. This is for speach only. > > ----- Original Message ----- > From: "Bob Ammerman" > To: > Sent: Thursday, November 16, 2000 10:15 PM > Subject: [PICLIST] [EE]: mp3 player > > > You won't be able to build a MP3 decoder around a PIC. It doesn't have > > enough memory, nor enough processing power! > > > > Bob Ammerman > > RAm Systems > > (contract development of high performance, high function, low-level > > software) > > > > ----- Original Message ----- > > From: Miroslav Tzvetkov > > To: > > Sent: Thursday, November 16, 2000 4:10 PM > > Subject: Re: [EE]: mp3 player > > > > > > > thanks , byt i'm looking for mp3 decoding alghorithm > > > > > > i want making mp3 decoder whit PIC microkontroler > > > ----------------------------- > > > Free mail from www.dir.bg! > > > > > > -- > > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > > > > > > > > -- > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > > > > > > > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu