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Tech Question!!!!

Whitesnake - Jul 6, 2002

		Whitesnake	Jul 6, 2002
		i have mentioned this before somewhere else but would it be possible to change the playback rate of the audio on ntsc games to match the pal speed of 50hz, i am using goldwave and am wondering what would i have to change it to for it to work, its currently at 44100hz.

		Arakon	Jul 6, 2002
		uh.. I hope you are aware that all music would run too slow then. besides, you can't downsample from 44100, since the audio cd standard requires the audio to be 44100 khz.

		Whitesnake	Jul 6, 2002
		oh yeah i forgot about that well is there anyway to change the speed of the audio for 50hz machines there would not really be much of a difference

		Curtis	Jul 6, 2002
		You could do this if you wanted. You could use a pitch shifter to reduce the length of the file by 17.5% (the diference between 50 and 60 Hz) . By doing this, however, you will end up with audio files that sound wrong - they will be the right length but will sound silly. The other option is to use a (usually) expensive piece of software that offers time stretching and compression facilities. I think Goldwave has one of these built in, but I don't think it is terribly good. This will allow you to adjust the length of the track with no noticable pitch shifting affects, but may also affect the audio in other ways depending on how much you use it. Again the aim is to make the track 17.5% longer (or shorter?) Neither way affects the playback rate (i.e. 44100Hz) that is important as Arakon says. Hope this is helpful to you.

		sizone	Jul 6, 2002
		sonic foundry sound forge does time compression/lengthening but their algorythims leave alot to be desired if the sound you're working on is more than a few seconds long or is more complex than one track (adds alot of nasty flange and distortion). digidesign pro tools has similar features and is free, as i haven't gotten around to trying it out however i have no idea as far as the quality

		Whitesnake	Jul 8, 2002
		thanks for the feeback,but when sega release a game in europe from america they must employ some audio technique to make it work.

		Curtis	Jul 8, 2002
		I think it is more likely that they change the speed of the animation that they are trying to sync the audio to, than alter the actual audio itself. If there is nothing that needs to be synced (like background music, for example) then you just loose a few seconds from the end of the track - no one is the wiser for it.

		King M	Jul 11, 2002
		i've never heard of audio being played at a different frequency in europe. the only references i've seen to the 50/60hz difference were talking about video. are you sure you need to change the audio? i think the audio on sega cd (or mega cd i guess) is standard red book cd audio.

		Curtis	Jul 11, 2002
		There are problems with the audio when you try to sync a video file with a standard CD audio track. If the audio is embedded in the video then you have no problems, but in games like Lunar, the "video" is really just a series of frames like an animated gif and audio is synced from a track of normal CD audio.

		M3d10n	Jul 12, 2002
		I'm no expert, but I guess such sync problems only happens if you use SCDConv. Try getting actual PAL versions, since those are re-programmed. Unless a game is programmed to react differently to NTSC/PAL, it will have problems when converted with SCDConv. A game that originally draws 60 frames at 60fps, takes 1 second to do it, will then draw the same 60 frames at 50fps, taking 1.2 second to do it. It's like running emulators on slow computers: the game will play slower, since it has no "frameskipping" feature programmed. This is also aggravated by the fact most console games use frames as time unit, instead of seconds/milliseconds. So they must be reprogrammed so they skip a few frames, or re-scale their speed variables.

		Curtis	Jul 13, 2002
		Yes you are right M3d10n - you will only have problems when using SCDConv on NTSC games. If the game is natively for a PAL system, then the programmers will have changed the length of the animation to match the music - if they are any good at what they do, this should be a few simple changes to a couple of lines of code.