FIX - iTunes Crash while "Determining Song Volume"

Question

I figured out how to make iTunes stop crashing on "Determining Song Volume". This may not fix it for everybody, but if you have a Dual-Core processor, it's worth a try.
iTunes' SoundCheck scanning process (aka determining song volume) is not fully thread-safe. When it's trying to scan several songs, it launches each one in a separate thread. On a dual-core or dual-processor machine, this means that the scans happen simultaneously. My guess is that the decoding/scanning is perfectly fine, but the bit where it's writing the updated information into iTunes database is not. And so it eventually hits a case where both threads try to write at the same instant and bam, crash. Probably because a lack of mutex locking on the database routines.
Anyway, if you're experiencing this problem, and have dual-cores, try this:
1. Start iTunes. If it starts scanning immediately, hit the X icon to the right of where it says "determining song volume" to make it stop and not crash.
2. Go to preferences and turn off SoundCheck. Also turn off "Use soundcheck when burning CDs" or something like that.
3. Open the Task Manager (CTRL-SHIFT-ESC). Click the Processes Tab.
4. Right click on the iTunes.exe process, and select "Set Affinity..."
5. You should have checkmarks beside CPU0 and CPU1. Turn off the CPU1 checkmark.
6. Back in iTunes, turn on SoundCheck again. It'll start determining song volume, and this time, it should not crash.
If this works for you, then you can make it semi-permanent with this little program: http://www.activeplus.com/us/freeware/runfirst/
It's called RunFirst.exe and what you do is to put a copy of it in the iTunes directory. Then change the shortcut you use to start iTunes to have the full path to runfirst.exe followed by the normal path to iTunes.exe. SO change the shortcut's properties to look like this:
"C:\Program Files\iTunes\RunFirst.exe" "C:\Program Files\iTunes\iTunes.exe"
This makes the shortcut launch RunFirst, which launches iTunes with the CPU Affinity forced to one core only.
That should fix it for a lot of people. It worked for me. So enjoy!
Apple can fix this in future revisions of iTunes, if somebody tells them to check that all the bits are totally thread-safe, because clearly that's where the issue lies.

Answer 1

Sarah: Sound Check (and other volume leveling schemes) usually do lower the volume. There's lot of good technical reasons for this, but the basic gist of it is that songs which are too loud cause distortion. If you want louder music, your best bet is to leave the Sound Check on and crack up the volume knob on the speakers instead. Most audio sources are actually too loud to begin with, because people think loud = better, but this ruins the dynamic range and you don't get the full effect of the audio. CD's really would sound just as good as live performances if it were not for this.
Sound Check doesn't actually change the song's volume itself. It just inserts a tag saying what the volume of the song is. On playback, the volume is auto adjusted to conform to an optimum level. ReplayGain works in much the same way, but it is much more precise. But anyway, turning off the Sound Check option really does turn the effect off. Sound Check doesn't permenantly change the music to begin with.
My suggestion is to not use the volume slider on the computer, but to leave Sound Check on, and to instead simply turn up the volume on the speakers. Using the speaker volume won't distort the music in the same way that using a volume slider on the computer will. I could explain why, but it's really technical, having to do with amps and dynamic range and so forth. You're probably not that interested.
But if you are interested, go over to the HydrogenAudio forums and start reading. More technical gibberish there than you can shake a stick at.