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kuma4649 / mml2vgm

GNU General Public License v3.0
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Support K054539? #123

Closed musicalman closed 7 months ago

musicalman commented 2 years ago

こんにちは。 私はコナミのK054539サウンドチップのサポートをお願いしています。 これはK053260の後継で、私の意見では大きく改善されています。 サポートを追加することは可能だと思いますか？お時間をいただきありがとうございます。

ghost commented 2 years ago

Gonna throw in a quick warning that the current emulation of the 054539 chip has it's flaws tho. Namely, the 4-bit DPCM decoding appears to be incorrect, resulting in artifacts in DPCM samples. (8-bit and 16-bit PCM samples appear to be fine) Additionally, the Echo/Reverb isn't emulated either.

May be probably best to disallow using the Reverb and 4-bit DPCM samples until the emulation in those two aspects has improved.

musicalman commented 2 years ago

Thanks for the heads-up! I've heard some truly horrible dpcm emulation with this chip, but vgmplay doesn't give me anything nearly that awful. Whether it's accurate or not I don't know. In vgmplay some tracks have echo/reverb applied but the echo appears pitch shifted down an octave. MDPlayer does the same, so I wouldn't doubt it's weird atm. In any case, mml2vgm doesn't support dpcm or reverb on similar chips yet, so omitting these features wouldn't be a big issue for me.

kuma4649 commented 2 years ago

OPXが残念な状態なので、あまり気が進まないですね。。。

musicalman commented 2 years ago

混乱しています。K054539のエミュレーションはOPXのように未熟だとおっしゃるのですか？

kuma4649 commented 2 years ago

そういうことです。 気が向いたらサポートしますｗ

musicalman commented 2 years ago

ああ、私はエミュレーションが悪かったことを知りませんでした。 私はそれを使うことに興奮しました。 しかし、私はあなたが快適に感じていないかどうかを理解しています。

SaxxonPike commented 2 years ago

Hello! I just happened to find your project while searching for K054539 filter info while I improve the DPCM support in MAME.

You may use this table of deltas for your own K054539 emulation, which I have found to be more correct and do not result in a DC offset in samples I have tried: { 0, 1, 2, 4, 8, 16, 32, 64, 0, -64, -32, -16, -8, -4, -2, -1 }

As for reverb, it's probably a FIR filter (like the SPC700) but we do not know the taps for it yet.

kuma4649 commented 2 years ago

こんばんは。申し訳ありません。 音源chipの対応は基本的にvgmplayか、mameの対応を待ってそれに合わせてこちらも移植しています。 ですので、ご提案はありがたいのですが、mameの開発チームに向けていただいたほうが良いです。

SaxxonPike commented 2 years ago

You make a good point. So, I have contributed my changes to mame. They are now merged. I hope you can find this useful.

https://github.com/mamedev/mame/pull/9778