Well, after almost a year of hibernation, I brought my MSX back to life. I equipped my MSX tR with hard disk and CD-ROM (all this is in fact for sake of playing eva files). But the experience was not that astounding, becouse despite video goes smoothly, the audio jitters. I play eva files from a 24X CD-ROM. Any clue to get rid of that annoying jitters?
Thanks

You say you have an MSX turboR. I say you try the /W and the /V command line options. Usually the /W takes care of the audio jitter.

Thanks for the replay, though I couldn't have time to use my MSX and try the options.
Well, Amestrad CPC SymbOS has a video player www.symbos.de/files/videoplay.gif with a control panel (play/stop, forward/backward) while the EVA player has not? Can that be implemented in evaide.com?

few questions...

Does the EVA player works on a pure z80 ?

Who does develop/mantain the EVA players for MSX?

Who knows how the audio of EVA files is encoded and played (what is the covox device I have seen)?

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(play/stop, forward/backward) while the EVA player has not? Can that be implemented in evaide.com?

There is no reason, why it could not be done. If you want to do that, EVAIDE sources can be found here.

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There is no reason, why it could not be done. If you want to do that, EVAIDE sources can be found here.

Well, I'm just talking the talk, not walking the talk . It was just an idea that came into my mind when I saw that CPC Symbos.

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Does the EVA player works on a pure z80 ?

It's 100% Z80 assembly if that's what you mean. It's also not specifically R800 if that's what you meant.

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Who knows how the audio of EVA files is encoded and played (what is the covox device I have seen)?

Audio is not encoded, it's just raw PCM data. It's played by just outputting the data to the respective port, which is either the tR PCM, Music Module or covox dac port. A covox is a simple parallel port DAC that is connected to the printer port. Just search for the word on the net, you'll see.

So, if I modify audio section of the EVA encoder/decoder including the algorithms of PCMENC,
I could get on a z80@3.57MHz a full eva player that does PCM audio and straming video on MSX2...

Correct?

If that PCMENC can decode 15.75kHz sound in reasonable time, yes.

Before I forget though, MSX2 would really need V9990 for the video data, although you could convert your EVA files to downscale them to screen 8.

Hi D-Tail
The re-player of pcmenc is very light, and can go to up to 44,1KHz with 3 bit LRE, without encoding could also rise the frequency rate (at about 70KHz), but at the cost of a huge waste of space (3bytes per sample @ 15KHz is a lot of space).
The problem is that "very light" couldn't be enough when you have to do video decoding at the same time.
How heavy is the video-decoding of Eva files? What is the encoding algorithm ?
How many Tcycles per frame are required ?

Video encoding is just like the sound encoding: zero. It's just raw YJK data (or RGB data, depending on your EVA file) which is sent directly to the Video RAM. It's said (though because of lack of experience I can't confirm) that pumping the video data to the VRAM is the most time consuming process. Calculate for yourself: 128*106 pixels * 8bpp * 12fps = 159kB/s, or 13,25kB/frame. Then there's also the 10FPS variant of the EVA movie, which has a slightly different file format. I encorporated both in EVAcon - I could send you the Java source, if you would be interested in it.

To be honest, I'm dying to have a decent EVA replayer for MSXDOS(2) - with usable controls and the like. But due to my lack of skill in the ASM department, I can't make it myself.

How do you play the data?
Do you store the full file in the ram ?
Do you play the file directly from the HD disk?

In 0,083333333 secs I should

load form the disk 13568 bytes
send to the Vram 13568 bytes
load from the disk 4000 bytes (3*16KHz * 0.0833333, I am thinking to PCMENC audio)
out to the PSG 4000 bytes

does it work in this way?

I don't know exactly how the IDE device is controlled, so I don't really know how the EVA data is loaded... My guess would be that it's streamed from the disk, and it gets the data as needed. I could be entirely wrong tho... ^_^ Anyhow, have a look at the sources of the MSX replayer idd, you should be able to figure something out... I have info on the file format if that's what you need, but you can also easily obtain that by looking at the source. Audio and video data is interleaved in the 12fps format, having small chunks of video data followed by a few bytes of audio. The 10FPS format seperates the audio data from the video data completely, suggesting the data is either not streamed, or is streamed from RAM with a frame delay. Like said, I don't know enough about the IDE to really know what's going on, perhaps you do. Let me know if you need the format info.

EVA video is sent to VDP directly from IDE-controller using OTI and OTD commands, so there is no RAM buffering except in 10fps format where the next frame sound is buffered.

ARTRAG: It may be a bit hard to implement decent PSG playback to EVA. I would suggest, you make your own movie format, that implements PSG playback and uses SCREEN 2 to play video. This way you can use even more space for audio as full 256*212 screen of SC2 data is only 13824 bytes and color pallette is 45 nibbles.