Whether the ADPCM-A of OPNB can seamlessly switch PCM sampling.

[Denjhang Liu]

For OPNB, ADPCM-A can only use 18.5khz wav, and the longest audio is about 30 seconds. I recently used a large section of wav samples as PCM samples. I cut several minutes of audio into a file every 30 seconds and defined it as @0, @1, @2, etc. I found that there is a very short interval between @0C and @1c. Can it be eliminated?
magic.zip
The file contains a few minutes OPNB VGM, using only ADPCM-A.

[Denjhang Liu]

The vgm I uploaded has a very short interval every 30 seconds.

[kuma]

恐らく、この問題は解決しません。
発音タイミングは、PCMの合成処理とは別に存在し、正確な同期が不可能だからです。

[Denjhang Liu]

Is it possible to advance @1c by a few milliseconds? Does the existing command have this function?
If you can make @1c a few milliseconds in advance, you can make up for this gap.

[kuma]

ありません。

[Denjhang Liu]

I found a strange way to temporarily solve the problem. I analyzed the output wav and found that there is an interval of about 0.056 seconds in each 30-second segment, so I used the following method to solve the problem. But the effect is not very good
'T15 T8 p2 l1 @20c r1024 @22c r1024 @24c
'T16 T8 p2 l1 r1024 @21c1024 r~1024 @23c r

[Denjhang Liu]

[Denjhang Liu]

In my impression, many neogeo arcade games use ADPCM-A or ADPCM-B audio streams that last several minutes. How is that done?

[kuma]

おそらく、予め曲のテンポを決めておいて、フレーズごとにサンプリングしていると思います。
後はフレーズが始まるタイミングでキーオンするのみかと。

[kuma]

閉じますね。