--- Simon Jenkins <[EMAIL PROTECTED]> wrote: > ok: > > ~ Downsampling by 50??? That's *got* to require > some > filtering. In keeping with your need for speed - not > to mention > my lack of DSP guru-head - i've implemented the > crudest > imagineable. > > ~ fseek()-ing the pipe wasn't working. I've removed > the > first fseek(), but that means that g_startTime is no > longer > honoured and must be left at zero. The (ahem) > "filter" i > added means the second fseek() is no longer > required. > > ~ A couple of math corrections. > > ~ Widened expected bpm range: It now looks for 100 - > 199 bpm. > You should probably narrow that back down again if > you know > your source is in a narrower range. > > I actually ran it a couple of times and it seems to > produce plausible > results now though i don't have the exact bpms for > the mp3s i tried. > Also, my test mp3s contained looped samples and/or > programmed > drum parts. I'm not sure this algorithm will work so > well (or at > all for that matter) on less regular material. > > Simon Jenkins > (Bristol, UK) >
Simon, Thanks so much for lending a hand :) I was working on it too tonight, and received your email about 30 seconds after I got it working, hehe. I found that while it's not "supported", the fseek works fine for me. The man pages for fseek say that it can't be used on pipes opened for /writing/. Obviously we're just reading from a pipe..and while errno is still set to EPIPE, it works here. However, I don't like hacks, and so I'll replace all piping / reliance on mpg123 with calls to libmad. You are dead on with the downsampling issue. With a downsampleFactor of 1 or 2 the program works great for me now - 50 was way too high. I know jack sh!t about filtering..or PCM in general. But the program, while slower, is now at least as accurate as my Numark CDN-88's Beatkeeper III. Again, I'm really greatful for your help. I'll attach a completed version soon, hopefully. Take care, ===== Jay Dolan Software Engineer, Systems Analyst Windmill Cycles, Inc. 508.999.4000 __________________________________ Do you Yahoo!? Yahoo! Finance Tax Center - File online. File on time. http://taxes.yahoo.com/filing.html
