Cdxl vs yafa

[Cobe]

This needs more testing but initial tests are promising. Not tested on real cd32 yet. The goal is to play anims from cd of course so the limit is 300kb/s.

This is the best I could get so far with test anim:

cdxl anim: 208x156 12.5fps ham6 no audio
cdxl anim: 204x152 12.5fps ham6 with audio
yafa anim: 248x186 12.5fps ham6 no audio with audio workaround

iso v1
https://drive.google.com/file/d/1Xks...w?usp=drivesdk
iso v2
https://drive.google.com/file/d/1Joz...w?usp=drivesdk
iso v3
https://drive.google.com/file/d/1OUZ...w?usp=drivesdk

iso plays cdxl, than yafa anim, and loops

The reason why they have no audio is cause I read that yafa has 128kb limit for sample size. Probably I'd had to split audio but that would probably lead to stutter every time it loads sample during animation. But I didn't experiment yet. Now, yafa player has advantage that it can play mods. So one day I'll either use mod music or make mod with split samples so everything would be loaded at once. Though, I don't know why I never thought about that, but probably I could play mod with cdxl too by simple multitasking...
Seems that cdgsxl is not that system friendly as I thought I remember... but yafa player is.

First I tried xpk for yafa and the files were significantly smaller but although 020 w/o fast ram can play them from hdd it stutters from cd.
I settled with byte delta compression which also makes smaller files, just enough smaller to make noticeable differences when compered to cdxl and doesn't stutter when played from cd.

Also along the way, older yafa player v.0.78 turned out to access the cd faster than v.1.0.2

[Samurai_Crow]

The 128k limit for samples is a Paula hardware limit. CDXL streams audio interleaved with the data stream leaving two voices unused. I'm not as familiar with YAFA but I know there is a codec for YAFA on Hollywood making it the preferred format for cross-platform development.

[Glen M]

After playing with the AGA Blaster player I can't help but think the performance is mostly down to how fast you can stream the file and with only 300kbps to play with the quality needs to take a massive hit.

It might be worth having a chat with Earok who ported Time Gal and Road Avenger both of which stream the video and audio from disc I think using CDXL.

[Amigajay]

Originally Posted by Glen M

After playing with the AGA Blaster player I can't help but think the performance is mostly down to how fast you can stream the file and with only 300kbps to play with the quality needs to take a massive hit.

It might be worth having a chat with Earok who ported Time Gal and Road Avenger both of which stream the video and audio from disc I think using CDXL.

Of course data streaming on disc always comes down to the drive speed, the CD32 is already pushed to the max, the quality can't possibly be any bigger in size or higher in quality without a much better CPU/GPU de-compressing on the fly

[Glen M]

Originally Posted by Amigajay

Of course data streaming on disc always comes down to the drive speed, the CD32 is already pushed to the max, the quality can't possibly be any bigger in size or higher in quality without a much better CPU/GPU de-compressing on the fly

I'm not convinced that streaming 300kbps pushes the CD32 even stock to its limits but its impossible to put an estimate on just what would be capable due to the 300kbps limit so yes my comment is a null point.

I suppose what I was getting at was that on the discussion about AGA Blaster most people reported 17ish fps on their TF330 streaming from CF card but I am getting a perfectly stable 24fps which I can only put down to the very fast CF card that sits just under 6mb/s. Again a null point in this discussion but I just thought I'd mention it.

[Amigajay]

When i said pushes the CD32 to the max, i mean’t streaming from disc with its 300/k sec drive, of course you can get better streaming from HDD and even more from the TF330.

I think the conversion of the ‘Only Amiga’ or Ashley Cotter Cairns CDXL vids i did, cant remember the exact resolution but with sdl the screen area was quite big i don’t think with a 300/k drive it could get any better without hardware like the FMV card,

[Cobe]

Originally Posted by Samurai_Crow

The 128k limit for samples is a Paula hardware limit. CDXL streams audio interleaved with the data stream leaving two voices unused. I'm not as familiar with YAFA but I know there is a codec for YAFA on Hollywood making it the preferred format for cross-platform development.

yup, I read its actually Paula's limit. I guess that holywood codec overcomes this obstacle in one or another way. Would be interesting to read how they did it..

Originally Posted by Glen M

It might be worth having a chat with Earok who ported Time Gal and Road Avenger both of which stream the video and audio from disc I think using CDXL.

He didn't use cdxl, he used his own method. I was expecting him to pop up already

Originally Posted by Glen M

I suppose what I was getting at was that on the discussion about AGA Blaster most people reported 17ish fps on their TF330 streaming from CF card but I am getting a perfectly stable 24fps which I can only put down to the very fast CF card that sits just under 6mb/s. Again a null point in this discussion but I just thought I'd mention it.

Those are 320x200 vids?

Amigajay has all valid points.
But yafa proves that with delta compression videos can be 20ish% larger/better on the same bandwidth. Though I kinda have a feeling that in yafa case cpu waits disk dma to be finished...

And I also don't have clear picture how cpu and chipset share chipmem. I read that cpu use even cycles and chipset odd so that cpu could work in parallel. But someone more knowledgeable would be nice to write how exactly this works and am I pursuing something that's not possible or is it possible to have full disk dma stream non stop and cpu decompressing in the same time?

Also I'd be interested to hear from someone which xpk sublibrary has fastest decompresion on 020.

[Samurai_Crow]

Re:Hollywood audio

...is AHI all the way with CPU based mixing if you don't have a sound card.

[Glen M]

Originally Posted by Cobe

He didn't use cdxl, he used his own method. I was expecting him to pop up already

Really, thats very interesting as I could have swore it was CDXL.

Originally Posted by Cobe

Those are 320x200 vids?

320 x 256 actually and 256 colours all be it the converter is dynamic in its use of colour i.e. if it can get away with less it does. I'm going to be doing some more testing later at 640x256 to see how it copes.

Originally Posted by Cobe

Amigajay has all valid points.
But yafa proves that with delta compression videos can be 20ish% larger/better on the same bandwidth. Though I kinda have a feeling that in yafa case cpu waits disk dma to be finished...

And I also don't have clear picture how cpu and chipset share chipmem. I read that cpu use even cycles and chipset odd so that cpu could work in parallel. But someone more knowledgeable would be nice to write how exactly this works and am I pursuing something that's not possible or is it possible to have full disk dma stream non stop and cpu decompressing in the same time?

Also I'd be interested to hear from someone which xpk sublibrary has fastest decompresion on 020.

All that's way above my head to be honest. AmigaJay usually was valid points whereas most of mine are more

The biggest let down of CDXL really is the lack of compression so one of the videos i converted is 544mb and only 4.33 minutes long which works out to roughly 2mb/s so well out of the reach of the CD drive. You'd need to half the image size, the fps and the colour count to even get close.

I'll keep an eye on this thread though as it does interest me.

[Retro1234]

Did you ever test Hamp ? I don't know if it would be any better than CDXL.

[Cobe]

No. But I think its uncompressed and pretty much the same as cdxl.

[earok]

My ears are burning

Road Avenger / Time Gal don't use CDXL per se, but a custom format. Having said that, it has identical limitations to CDXL given that it's just storing uncompressed audio and video. It doesn't really stream the same way that CDXL does, but buffers around 1-1.5MB of video/audio data from the disk, and plays it and updates game logic while simultaneously loading the next chunk (hence, there's a short delay at the start of each level).

I'd certainly be interested in some means of playing back compressed video within the limitations of a stock CD32! I'll keep an eye on the thread and pitch in if I think of anything.

[Retro1234]

Would this work? http://eab.abime.net/showthread.php?...81#post1378281

Obviously with good dithering you can reduce the colour without too much loss of quality and decreases the file size.