Orri Ganel wrote: > Hello all, > > I've been working on a program for a week or two now that will convert > all the wav files in a folder to mp3s, filling the id3 tags with the > correct information as collected from gracenote.com. This part works > fine. However, the actual conversion to mp3 takes between 30 and 50 > seconds per song, so it's usually about 10 minutes per album. With this > in mind, I thought, why not try to use threads so all the conversions > happen simultaneously? That way, the whole album will take between 30 > and 50 seconds. Unfortunately, I can't seem to get a working threaded > version that significantly reduces the time involved . . . The
The only part you are doing in a thread is the actual conversion. This is likely to be CPU-intensive so running it in multiple threads may not help - you still have only the one CPU to run on. To the extent that you can overlap disk I/O in one conversion with processing in another you may get a win; on the other hand you could just as well have contention for the disk as you try to read and write a bunch of files at the same time. The fetch from gracenote.com seems like a better candidate for threading because there is some latency...but the total time is still probably small compared to the conversion time. Maybe if you have multiple CPUs you can get a speedup by using as many threads as CPUs...I'm not sure how os.system() behaves in this case. You may have to explicitly fork to get a new process. Hmm...come to think of it, os.system() may block other threads, I don't know...you could try subprocess.Popen() instead. Kent > unthreaded version is available at > http://rafb.net/paste/results/Y1DTnW54.html, and the current, only > slightly time-improved threaded version is available at > http://rafb.net/paste/results/Lvsjj495.html. Any and all suggestions as > to how to threadify this are welcome. I realize the code isn't as > pretty as it could be, but first I want to make a threaded version that > works. Once this has been accomplished, I'll finish commenting the code > and making it more user-friendly to read. > > Thanks in advance, > Orri > > P.S. - In order to make my code work, it is necessary to download > several modules. Once the code works, I'll include above the code a > comment listing all the requirements. Right now, I believe the following > modules are needed: > > ClientForm - http://wwwsearch.sourceforge.net/ClientForm/ > id3writer - > http://www.comfortableshoe.co.uk/cgi-bin/blosxom.cgi/Home/Python/id3Writer.comments > > (click the "download link" link) > id3reader - > http://www.comfortableshoe.co.uk/cgi-bin/blosxom.cgi/Home/Python/id3Writer.comments > > (click the "Ned Batchelder's id3Reader" link) > PyID3 - http://sourceforge.net/projects/pyid3 > threadpool - http://chrisarndt.de/en/software/python/threadpool.html > > I also considered using the following, but decided not to for reasons of > difficulty of use or lack of desired operations: > > PyID3Tag - http://superduper.net/?page=pyid3tag > ID3-Py - http://id3-py.sourceforge.net/ > > The following non-Python program is also needed: > > Lame - http://lame.sourceforge.net/download/download.html > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
