Some tips for game recordings compression?

[itxaka]

Hello everybody!

I normally record some videos from dosbox/Scummvm for personal use and collection. This are old adventure games mostly so near pixel perfection is needed in the final videos.

Normally in Dosbox I use the ZMBV (http://wiki.multimedia.cx/index.php?title=DosBox_Capture_Codec) codec included as it's mandatory, but also because it gives me awesome results. Small files with no artifacts and no loss of colors (I don't know if it's losless, but it looks like it is)

For scummvm I normally use TSCC as is a almost losless(again, not sure but it looks like it is) codec that gives me good videos without the size of the uncompressed files and a really good speed.

But I want to encode them to a more "normal" codec but I found that normally any codec out there gives me a really bad image size vs compression.

For example, a TSCC video of 4:30 weigths about 32Mb at 30fps 879Kbps. The same video encoded with Xvid in Cartoon mode (It's an old adveture game, the Dig) gives me a 29Mb file at 798Kbps with artifacts.

Is there any tips on xvid/divx encoding to make those videos look better?

Will I be better using x264 losless?

Has something to do with it the colors? Old games had so little colors that maybe I had to force some special options?

What is recommended for a good no-artifacts compression for videos with 256 colors and low bitrate (Im talking about 90kbps bitrate for example)?

Much appreciated!!

[Dark Shikari]

ZBMV is lossless, yes.

x264 is going to be better than most anything else, but you're still going to have trouble going to that low a bitrate. Try and see how it goes.

x264 lossless will give a whole lot better compression than ZBMV I would think, but it'll still probably be larger than you want.

[itxaka]

ZBMV is lossless, yes.

x264 is going to be better than most anything else, but you're still going to have trouble going to that low a bitrate. Try and see how it goes.

x264 lossless will give a whole lot better compression than ZBMV I would think, but it'll still probably be larger than you want.

thanks for the answer!

After some tries, yes, x264 is MUCH better than any other codec. Not only it doesn't increase the filesize, but it decreases it!

As I can see the codec doubles the bitrate with the losless profile. 2 recordings went from 74/90 Kbps to 150/190 Kbps

The good part is, the file size. The bad part is the videos are looking a bit blurry and I'm a little loss with x264 options in MEgui.

Is there any option to sharpen the image?

Will it improve if I choose "Source is anime" when creating the Avisynth file?


Thanks!

[Esurnir]

x264 lossless doesn't really have a bitrate, it simply try to make the file as small as it can without applying any "quantization" (the step that make the file loose quality), on the other hand this codec is the most resource hungry in encoding and decoding you can find anywhere. If you want smaller file than x264, like a predetermined filesize, since your encoding a game I would advise you if your using MEGUI to do the encodes to use the non anime profiles in megui like Unrestricted 2 pass balanced or DXVA SD ballanced if you wish to send them over the net, anime profiles disable psy-rdo which in the case of games is a bad idea since you want to retain more detail while anime viewer don't mind a little blurriness.

[Dark Shikari]

thanks for the answer!

After some tries, yes, x264 is MUCH better than any other codec. Not only it doesn't increase the filesize, but it decreases it!

As I can see the codec doubles the bitrate with the losless profile. 2 recordings went from 74/90 Kbps to 150/190 Kbps

The good part is, the file size. The bad part is the videos are looking a bit blurry and I'm a little loss with x264 options in MEgui.

Is there any option to sharpen the image?

Will it improve if I choose "Source is anime" when creating the Avisynth file?


Thanks!The inherent problem with the YV12 colorspace is edges between colors will get a bit blurred.

You could try resizing 2x upwards before encoding, but that's silly.