Screenshots of Rebecka Liljeberg in Sajber

All screenshots in one file (with slightly higher quality). Just download the file, unpack somewhere and doubleclick on index.html.

Interview in full: 20.3MB MPEG1, 40.7MB MPEG2 and 10.2MB DivX.

Other TV appearances


This time I finally seriously tried MPEG4/DivX for compression. A lot of promises have been made about this "wonder" compression. I am not that optimistic about it. Yes, it can deliver better results than MPEG1 or 2 when the bitrates are really low. But it is not right to say that DivX/MPEG4 can deliver virtually DVD quality results with far less bitrate. Everything has its price, so does low bitrate.

One thing to consider is that DVD movies are digitized/captured with very, very high quality, then painstakingly cleaned of all remaining noise and other garbage. This makes DVD movies hugely easier to compress. On the other hand it means that when we have a more usual video capture, one that is more noisy, not so "perfect", much of the glory of low-bitrate compression disappears. MPEG4 doesn't produce MPEG1/2 comparable files even with equal bitrates when the source isn't perfectly clean. The results still remain lifeless compared to MPEG1/2 versions.

In this case I decided that I want to see what can be done with half of MPEG1/VCD bitrate. I played for a while with VirtualDub recompression utility together with AngelPotion V1.build.702 and DivX v3.11 alpha MPEG4 codecs. I started out with AngelPotion codec and quickly realized that something was seriously wrong. When I played back clips made with any of AngelPotion supported codecs (AngelPotion AP41 or Slow Motion DivX), with any bitrate and played them back with Microsoft Media Player 6.2, results were really blocky. Much more so than I expected. After some investigating I noticed that when I played back the same clips inside VirtualDub, the blockiness was all but gone. With higher bitrates it WAS gone. I then remembered seeing something like that with one of the better looking DivX movies I had seen (Cruel Intentions) - I really liked it in VirtualDub but it sucked badly in Media Player.

I then tried to reproduce the same image quality in VirtualDub that I saw in Media Player. As a sidenote it is probably neccessary to point out that I run my display in True Colour (24/32bit mode at all times, I never use 16bit colour). After a bit of testing I found out that VirtualDub shows the same result as MediaPlayer 6.x + AngelPotion codec when I select 16bit colour in Video menu, Color depth dialog, Decompression format selector. In other words, I am convinced that when DivX movies are played with MediaPlayer 6.x and AngelPotion codec (actually also DivX v3.11 Video for Windows decompressor as long as DivX DirectShow filter is not installed), the image quality is actually really poor because 16bit colour is used in a critical stage of decompression.

I then started to search for a way of viewing these clips with proper colours. First, I found that original, OLD Media Player 1.0 that comes bundled with Windows95/98 (Start/Run -> mplayer.exe), plays them properly. Player user interface, however, is awful and when one forces the image into full screen mode with that player, it forces display into some really weird resolution and mode. I then found that after properly installing DivX 3.11 alpha codec, colours reverted back to proper ones. I.e. even Media Player 6.x plays DivX movies with proper colours when DivX v3.11 is installed. I traced this improvement to DivX DirectShow filter that comes bundled with DivX codec files.

So. To see DivX movies properly, it is NOT enough to install AngelPotion codec and start watching movies. Come to think of it, there is maybe no real reason to use AngelPotion codec at all - it compresses alright, but it is poor on playback (it maybe fast, but the results are ugly). DivX v3.11 is the right codec.

Sulo Kallas