Soundmap cleanup, file writing, beta preparation

Today I started with the planned cleanup of the revised soundmap playback code. This took some time but I had it finished my mid-afternoon (please note that I have small children around, which can sometimes make the progress quite slow).

By way of final test I did a 10 minute Burn:Cycle game session; there's still an audio decoding issue there because some parts of the music crackle heavily.

Then I continued working on the WAV / AVI writing front. I have this essentially working now; both types of files are correctly written (the AVI files now include both audio and video). There are new options -writewav and -writeavi to invoke these functions from the command line.

I used the WAV writing feature to check out the Burn:Cycle audio decoding issue. The audio samples go way out of range at the point of the crackles (they actually clamp against the minimum/maximum values). There is probably something wrong in the scaling or something.

One generic issue with WAV file writing is that silent periods (where the CD-i application doesn't play any audio) do not show up in the recorded audio. For the moment, I've decided that this is a feature :-)

There is also some kind of audio timing issue in AVI file writing; the recorded files sometimes sound "skippy". However, this may also be related to the speed of my PC; these are uncompressed AVI files which take 61.5 MB per second for the CD-i video data alone (50 x 3 x 768 x 560 bytes per second). Compared to this, audio is only a measly 172 KB per second :-)

I've found that real-time AVI writing is nearly impossible on my hardware; the framerate drops below 2/50 sometimes (I've lowered the previous 10/50 limit) which makes the titles unplayable. Tomorrow I'll try my work PC which is much faster. That should also give me an opportunity to add frame rate throttling; on fast PC's the emulator currently runs too fast.

However, non-realtime AVI writing also gives the "skippy" sound, so it may be unrelated. Sometimes the audio also gets way out of sync...

One worrying generic issue is that CD-i Emulator seems to have become slower as of late, for no good reason that I can think of. It may be that some debugging code somewhere is slowing things down, but I haven't found it yet. Or it could be that the titles I'm currently running are simple more demanding...

During testing, I also fixed a recent bug where mouse input and keyboard input interfere with each other. I also took out the use of the Shift key for button 2, as it is prone to generate false button presses when using Alt-Tab / Shift-Alt-Tab to switch between windows. You can still use the numeric "+" key for button 2, though, but that is too far away for generic use: I need an alternative closer to the space bar. Perhaps Backspace for button 2, and Esc for button 3 (buttons 1 and 2 together)?

Finally, I've started putting together the first v0.5.3 beta distribution. It will be mostly identical to a v0.5.2 one, with some updates in the sys directory, updated cdiroms.ini and cditypes.rul files and of course an updated executable which will be named wcdiemu-v053b1.exe (for beta 1) to avoid accidentally overwriting an existing v0.5.2 executable. I've also taken a first crack at a release notes document (very descriptively named BETA1).