MagicEngine

[michaeljamesjohnson]

So I was thinking of a few things I would like to see in MagicEngine:

1. You know how we can now show FPS and screen resolution while playing a game? What if we added a few more such as PC Engine CPU speed, RAM usage and sound file stats (i.e. 2 channel, 16-bit, 44.1kHz)?

2. Would it be possible to integrate Vista's WASAPI mode for audio in MagicEngine? Just wondering if bit perfect is possible for a gaming emulator when it comes to sound.

Thanks for the awesome work you are doing!

[dmichel]

If you overclock the CPU MagicEngine will display the frequency in MHz under the FPS counter.

For RAM and sound, hmm I don't know, they are pretty static values, sound is always the same and RAM usage doesn't change much while the emulator is running.
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David Michel

[michaeljamesjohnson]

I am talking about the PC Engine RAM and Sound just so we are on the same page.

I would be interested to know the stats of sounds that are playing and if they change during gameplay kinda like screen resolutions change in some games. Mono, 2 channel, 8-bit, 16-bit, 32kHz, 44.1kHz, etc. etc.

RAM is not a big deal, but again would be interesting. Wonder if it would be possible to overclock the PC Engine RAM just like the CPU?

[dmichel]

Oh, OK...

Yes, I could add a little RAM/ROM size indicator, is it what you mean?

For audio it doesn't change much, only CD/SCD games have a channel with variable sampling rate, from 2 to 32KHz, but usualy games only use 16KHz. Otherwise for HuCard that have voices and/or drums they are always 5-bit, 7KHz.

About RAM overclocking, it's already done, when you overclock the CPU the RAM is automaticaly overclocked too
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David Michel

[michaeljamesjohnson]

Yes, a real time RAM/ROM size indicator would be cool.

In regards to audio...


It appears to me that most PC Engine CD audio files are 2 channel, 16-bit, 44.1kHz when ripped to wav using an application like Exact Audio Copy. Are you stating that the PC Engine console never did or was never capable of sending a signal in this format to the internal PC Engine DAC? (Digital to Analog Convertor) If this is true, then I'm guessing the DAC simply did not support full 2 channel, 16-bit, 44.1kHz CD audio...

Looking on Wikipedia, I am really confused regarding PC Engine (HuCard) audio. I do see 5-bits mentioned and 6.99kHz, but a lot of other stuff is mentioned too.

So what happens when playing a PC Engine CD game? Does the CD audio (aka Redbook) and non-CD audio get mixed together and scaled, up-sampled, down-sampled, etc., to one single format before the Digital to Analog Conversion takes place? Something like this must happen, because a DAC can only lock on to one single format at a time the way I understand it. In the case of an emulator running on a PC, I am not familiar with a sound card that can support 5-bit, 6.99kHz sound files, so something is probably changing the format in the chain (i.e. MagicEngine, Windows, Sound Card driver, etc.) to a format that is supported by the sound card.


I still think it would be cool to have a few lines under the FPS/CPU/Resolution meter related to audio:

Line 1 = PC Engine CD native redbook audio stats in real time

Line 2 = PC Engine non-CD (i.e. HuCard) native audio stats in real time

Line 3 = Resulting mixed audio stats in real time just before hitting the internal PC Engine DAC so we can see what happens mainly in CD games.



Obviously the above may be totally incorrect if I am misunderstanding.


Sorry to keep this going, but I am really interested in the audio side of MagicEngine now that the video side is feature complete in my opinion.

[dmichel]

Oh, yes, the CD audio is 16-bit, 44KHz, but the PCE doesn't have a main DAC, each audio source has its own DAC and produce an analog signal that is mixed with all the others, there's no digital mixer, it's all analog. The PSG has six little 5-bit DAC, the ADPCM channel has a 12-bit DAC (2-32KHz), and the CD a 16-bit DAC (44.1KHz). I don't know exactly the frequency limit of the PSG DAC, I know it can play back waverforms at more than 44Khz but I dunno the maximun frequency. Internaly MagicEngine resamples the PSG at 44.1KHz, and the ADPCM at 32KHz, and it send those along with the CD at 44.1KHz to the sound card which will handle the mixing of all the channels (6 PSG + 1 ADPCM + 1 CD).

What I could add perhaps is two more bars in the VU-meter, one for ADPCM and one for CD.
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David Michel