Tran - Ambience (1994) [Digital Capture]
Channel: Paul Chattaway
Date: 2014-10-13

Ambience by Tran.  Not your typical PC demo, the effects are relatively simple for 1994, but it can be mesmerizing...  I let the music loop three times before stopping the demo.  Download links below if interested...

This capture looks best in 480p.  If you choose a lower quality, you lose the authentic chunkiness of the video.  Also, if you maximize this to full screen, the edges of the pixels will get "soft".  The maximum original VGA resolution was 640x480, and it looks best when viewed at that scale, even if it doesn't fill the screen.

This capture was made by DOSBox, which is proving to be quite capable of running a variety of DOS games and demos.  The default configuration of DOSBox worked fine, but cycles per millisecond was set to 66000.  Probably unnecessary.  For some reason the demo runs at half the normal framerate when first started up, quickly upping and then downing the framerate makes it work normally.

At no point was the video or audio ever converted to analog and back again.  Direct digital capture via the emulator.  Everything was kept in uncompressed RGB and PCM audio right up until making the final MP4.  So crisp it makes your eyes hurt a little :-P  by which I'm referring to just how clearly you can make out the low resolution used in those days.  The original capture was 100 frames per second, this demo uses a high (for the time) refresh rate, so you're not quite seeing the real thing, but if you're viewing this in 480p you are at least seeing every single pixel.  Getting this to look right took some manipulation of the video because they alternated between two different images on every refresh to get around the 256 colour limitation (and I suspect because it looked kinda trippy on CRT monitors).  On today's monitors it looks horrible, but I blended the two fields together and then converted the framerate to 29.97.  Aside from the field swapping, they also really tweaked the VGA mode they used and the raw capture was slightly underscanned - hence the narrow black bars on the sides.  The actual capture resolution was 624x199, I first duplicated every line to get to 624x398, then did a lanczos resize to 624x478 to correct the aspect ratio, and letterboxed to 640x480.  Looking at other YouTube postings of this and other demos, I don't see others putting in quite this much attention to detail... ;-)

The audio has never been analog, but it sounds kinda soft, due to the lower sampling rate used to make the audio samples for the music track.  The mixing rate was CD quality, however.

You can download the original DOS executable here:
http://paul.chattaway.com/clacomp/demo.repository/1994/a/

And, if you want a copy without YouTube compression artifacts (quite noticeable in some scenes), you can get a high quality MP4 here:
http://bigbox.chattaway.com/demos/Tran%20-%20Ambience%20(1994).mp4