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VirtualDub 1.5.0 is out. From the user's prospective, 1.5.0 consists mostly of bug fixes, not the revolutionary change you would expect from a major version bump. The reason for the major bump is that the program has been internally restructured, breaking out some code into libraries and cleaning up the build process significantly. Sources are no longer split across four archives and sylia.dll is no longer statically linked, which should simplify project management a bit.
That is not to say that there are no new features in this release, however. 1.5.0 is the first release to have audio filtering, which has been a requested feature for some time. Now, the audio filtering system is quite rough at this point -- it's not optimized, and the filter selection is a bit sparse. You also cannot write external audio filters yet, although that is definitely going to change. The current selection of audio filters consists mainly of miscellaneous algorithms that I have been playing with for a while within a sandbox WinAmp 2 plugin:
Center cut. The classic "vocal cut" filter, except that the output is stereo instead of mono. This is accomplished through FFT phase analysis; the output will have some warbling in it, but stereo separation is preserved. Also known as the "make your own karaoke to embarrass yourself with" filter.
Ratty phase shift. A time-domain, sawtooth-swept delay line, with rake-like correlation to smooth out the jumps. Good for about +/-20% variation in pitch.
Now, you might ask what a pitch shifter is good for with video. Well, 1.5.0 also contains a stretch filter that allows you to slow down or speed up audio, like a tweaked tape recorder. Combine a stretch and a matched pitch shift, and you get a time stretcher. If you set the pitch shifter and stretcher to the same ratio and tweak the video frame rate to match, you can speed up or slow down video. (Yes, you can now make "Sakura Saku" even faster!) I'm still looking for a better pitch shift algorithm -- the current version has problems with clicking when multiple dominant tones are present. I tried a frequency-domain version once, but it didn't work out too well: frequency-based algorithms don't like sharp attacks and tend to "smear" them, making percussives sound mushy.
That is not to say that there are no new features in this release, however. 1.5.0 is the first release to have audio filtering, which has been a requested feature for some time. Now, the audio filtering system is quite rough at this point -- it's not optimized, and the filter selection is a bit sparse. You also cannot write external audio filters yet, although that is definitely going to change. The current selection of audio filters consists mainly of miscellaneous algorithms that I have been playing with for a while within a sandbox WinAmp 2 plugin:
Center cut. The classic "vocal cut" filter, except that the output is stereo instead of mono. This is accomplished through FFT phase analysis; the output will have some warbling in it, but stereo separation is preserved. Also known as the "make your own karaoke to embarrass yourself with" filter.
Ratty phase shift. A time-domain, sawtooth-swept delay line, with rake-like correlation to smooth out the jumps. Good for about +/-20% variation in pitch.
Now, you might ask what a pitch shifter is good for with video. Well, 1.5.0 also contains a stretch filter that allows you to slow down or speed up audio, like a tweaked tape recorder. Combine a stretch and a matched pitch shift, and you get a time stretcher. If you set the pitch shifter and stretcher to the same ratio and tweak the video frame rate to match, you can speed up or slow down video. (Yes, you can now make "Sakura Saku" even faster!) I'm still looking for a better pitch shift algorithm -- the current version has problems with clicking when multiple dominant tones are present. I tried a frequency-domain version once, but it didn't work out too well: frequency-based algorithms don't like sharp attacks and tend to "smear" them, making percussives sound mushy.
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