CHD format not as good as people make out ?

[liveevil]

Hi, i've converted some CD32 and CDTV games to CHD format but i'm noticing some oddities with the files. For instance,

Battle Chess - Makes a very loud buzz noise when starting a game for about a second (it scared the life out of me!)

The Clue - A lot of the speech doesn't play the first second or so and sometimes no speech at all.

Tie Break - Same as The Clue, the speech doesn't always play properly and sometimes not at all.

Base Jumpers - Some white noise during logo.

Not sure what's causing this. If I extract the CHD's back to CUE/BIN then they play fine.

I'm using CHDMAN v5. Any other users of CHD's experiencing this (or not noticed ?). Are there better conversion flags to use to prevent this ?

[liveevil]

@Ian
@Retroplay

I read in another thread that you have converted a lot (or all) of your CD collection to the CHD format. Have you not experienced any of the issues I noted ? Or maybe you just haven't used them since you converted them all! I've only played 8 games in this CHD format and found 4 issues already (as stated in the first post).

[Retroplay]

I tried Base Jumpers CD32, redump image converted to chd v5.

WinUAE = buzz sound at Rasputin logo
MAME = no problem, audio is playing as it should.

[liveevil]

So it's a bug in WinUAE ? The 2 games with speech (The Clue and Tie break) are a bit annoying as it only plays part of the speech. As I said, i've only tried about 8 games so far and half of them have oddities. I'm wondering whether to hold off on converting to CHD.

[sonninnos]

The more there are tracks in the image, the more they begin to start at the wrong place, as in later than they should.

Easily noticed for example with Pinball Illusions since it has 39 tracks, and especially with the last table which uses the tracks at the end of the disc.

Better way to confirm is to copy and force the image as an audio CD by editing the first data track as audio in the CUE file, so that launching the disc boots the audio player.

I made a tiny change in the CHD code for libretro PUAE core, which makes CHD image sound exactly like the raw image. The image format is not to blame, but the reading of it.

[ransom1122]

All the games you mention work fine with Latest WinUae for me..

Battle Chess - No Buzz
The Clue - Speech is perfect
Tie Break - Speech is perfect
Base Jumpers - No White Noise

Pinball Illusions (Last Table) Extreme Sports - Works identical to my BIN/CUE/WAV version... Both copies on the last table's music after about 3 seconds launching the ball has a slight music silent pause. I assume that is how the game is made.

I have the CHD's and the CHDMAN I used so if you need send me a PM

[liveevil]

Thanks for the replies guys. I tried the files you uploaded for me ransom1122, thanks. Your 'Battle Chess' and 'Base Jumpers' have no buzz/white noise but the speech on 'The Clue' intro still only plays part of each sentence or doesn't play at all. Your CHDMAN version is mame0200. The one I use is mame0205. I tried converting Battle Chess again using your CHDMAN but I still get that really loud buzz when starting the game/tutorial !! I've used the redump version.

So why doesn't the speech play properly ? It's like it waits before it decides to play the sample and if the sample is short then you don't hear the beginning or anything.

[liveevil]

So I did a couple of tests. I downloaded the TOSEC versions of 'Battle Chess' and 'Base Jumpers', converted them to CHD and got NO loud buzzing/white noise (as stated above). So my solution to those problems are don't use ReDump when converting to CHD !!

When testing Battle Chess with CHD, the music starts abruptly like it's missed the first second or so (even on yours Ransom!). This doesn't happen when using CUE/BIN. So it's not starting the audio at the correct time. Is this the correct behaviour of CHD (even on MAME ?) or is it a WinUAE thing ?

[ransom1122]

I may have had the correct version of chdman and source files to begin with, without even knowing.

Try to experiment with multiple versions of chdman then if that fails use a different game source I guess

[liveevil]

@sonninos

I tried what you said about editing the cue file so that is plays as an audio CD then converted it to CHD. I tried Battle Chess and all the audio tracks seem to be silent for 2 or 3 seconds before the audio starts abruptly.

So CHD starts playing the audio track but you can't hear it until a few seconds later. Is this the correct behaviour of CHD ?

[sonninnos]

Originally Posted by liveevil

@sonninos

So CHD starts playing the audio track but you can't hear it until a few seconds later. Is this the correct behaviour of CHD ?

No it is not correct CHD behavior. Try the same file for example with a Sega CD emulator or some other that has a CD audio player built in. I can't make that same thing happen anywhere else except with WinUAE now that I found a cure in PUAE (which mainly uses WinUAE code).

And sure seems scary that an older version of chdman would do it right..

[liveevil]

So I just tried the Battle Chess CHD I made (that only plays the audio) in the GenesisPlusGX emulator in Retroarch and the audio tracks play fine ! No silence before the tracks start playing. So that means it's a problem with WinUAE ?

Here is the Battle Chess Audio CHD I made, (tracks 1 & 2 are the same) -

https://mega.nz/file/eop2GQ6I#pFOosh...h1KjZPzXXD_sMM

If you load it in WinUAE or Retroarch PUAE you will get a pause at the beginning of every audio track. In GenesisPlusGX the tracks play instantly and not cut off.

[Retroplay]

Try and load the chd in MAME, use this command:

mame cd32 -cdrom "[path to chd]/Battle Chess (Europe).chd"

Audio seems to play perfectly well to me.

WinUAE doesn't like it though, buzz before audio plays.

[Toni Wilen]

If there is already a fix and confirmed working CHD do work in other emulators, I'd like to see the fix first.

[liveevil]

Unfortunately I know nothing about code. The CHD link I posted above was made from Battle Chess CD32. I just made it so it would boot straight to the CD32 CD player. When playing any track there is a few seconds silence at the beginning of every track. When booting the CHD in the GenesisPlusGX CD player the tracks play instantly with no delay. Retroplay said that MAME also works better but I don't know how to run it. I didn't know CD32 was working on that. https://github.com/ekeeke/Genesis-Plus-GX/search?q=chd No idea what to look for, if anyone can help.

[Retroplay]

Did some testing with Battle Chess CD32.
It seems mode1/2352 raw audio is the culprit regarding WinUAE and the audio glitch.

TOSEC image:
Mode1/2048 + WAV audio converted to chd plays audio fine.

Redump image:
Mode1/2352 + raw audio converted to chd is problematic and makes the static scratching/buzzing sound.

[Toni Wilen]

Ah, that could explain it because my test files seemed to work.

[liveevil]

Thanks for testing Retroplay. Would you mind trying the CHD from the link I posted to see if the audio tracks play without a delay in the MAME CD32 CD player ?

[sonninnos]

Originally Posted by liveevil

So I just tried the Battle Chess CHD I made (that only plays the audio) in the GenesisPlusGX emulator in Retroarch and the audio tracks play fine ! No silence before the tracks start playing. So that means it's a problem with WinUAE ?

Here is the Battle Chess Audio CHD I made, (tracks 1 & 2 are the same) -

https://mega.nz/file/eop2GQ6I#pFOosh...h1KjZPzXXD_sMM

If you load it in WinUAE or Retroarch PUAE you will get a pause at the beginning of every audio track. In GenesisPlusGX the tracks play instantly and not cut off.

Thanks. It is definitely due to the pregaps. CHDMAN says that every track in that image has pregap value of 150, but it is defined differently in all tracks after 2 when the CUE is extracted:

  TRACK 01 AUDIO
    PREGAP 00:02:00
    INDEX 01 00:00:00
  TRACK 02 AUDIO
    PREGAP 00:02:00
    INDEX 01 01:57:02
  TRACK 03 AUDIO
    INDEX 00 03:54:04
    INDEX 01 03:56:04
  TRACK 04 AUDIO
    INDEX 00 06:27:06
    INDEX 01 06:29:06

If those PREGAPs are changed to 00:00:00 and INDEX 00 is replaced with 01, they start to play fine in WinUAE.

I tried to update the CHD handling code in PUAE with current MAME code, and that fixed those PREGAP tracks, but not yet those with double INDEX.

But I'll keep looking, since indeed GenesisPlusGX plays everything fine..

[Retroplay]

There are 2 second gaps specified in TOSEC and Redump cue sheets for Battle Chess CD32.