Delay script drifts off time. jdelay node latency or bug?

[whoopsydoodle]

For some reason this simple delay scriptnode patch results in a delay that drifts off time. With an additional latency getting compounded with each feedback loop.

Is this a bug in the jdelay? I briefly tried one of the other delay modules and it wasn't better.

HiseSnippet 1779.3oc6Z0raaaDDdojWYKGmzDzfdVmJb.REDsb7OnnvN9uViTaKD431S0XM4JqMhhKAIksUK50hdrOH8gHnO.8RAJPu0GgdonGSmYIo3RYIaIk3Df.SCX3c2YmY1gey2Ljz07kV7f.oOwn3gc83Di4n065F1bylLgKY2svIB55ZUxl6v5R1nqGKHfaSLLx+knDFEmhnt9m01f4vbs3oSQHGIEV7uVzVDlNas0elvwYGlM+PQaMoWb8csjtaJcjc.uIOsBwiY0hcJeeFJVNJwnv11hPoe8PVHOfXL0FR6t0aJO2MR9iDAhSb33.SRcPQQSuizwF8XbVxlMEN10RN0ADPK0RiA4ihAOjtmvVza9zXw8UKTJcG5wCibYcu7YbOSc2qhl6M.WxPyklJxkd.stkuvKLcEzetCcW2PteCFD10ckHYIFuhtoDDvMrbaVK9N9vfdaX9kpT4wkfe8nOuQGWqPgzsjzceYH+.24ezr+vrEm8GmsT+K0nw.WCMiuzwg6Ovkw6z9W0Fm2sS6S39OtzYLmN7dBBG+rwT5vio52xshN0ZBJc20UDdfG2cX.ARbnBh+4h8JPzPUz+dwQ+5NBatOQ.A4ooOyUdhIQ4vwn3W8eewetFYj2b0Latzu582qQdwtawBYHFH1c.Wzi6GJvSuwV7yfDpHDQQ5V7fVgROk+11S5hNuwzWqGeQZN2tq2Mcv9qGxu.z.k13jVDujPytvVmkFnzViKfjReHeDvP37QhRFCyWcnl+65Y9y4gip4+FPTxkyVf7TocGGVX1jWjwJdA.8kIiASKbCDgc0Yz5OidpQKi9pIbFU28AzZhPqlC1eyM.+EAt2v9aL+3coa2nA2JL0Ymhty29tiLb1XzEXSz3ZviAQB9yzTBGOeNff3GJqAUylOf01yg+bvCeboSbjVspK9d9kYohwhafRLuUSlqK2IXRHyJLxwDyqLlPdtrSnv8z8Xg9BHehtem10gxlV7Mi8NXNibHmVz3J3XDgTm6ZqF7Z3JdQSbrQ7hlIKlRGR1mGdtzuk5lQ7eCoyw8FnBxG23Bv849AHLExzqTF9g7TGG44H2fHF.C2TTyUS5z0qozUXgSEIQhq+z1xNHQRj++UrfCYBGDwWuS.vdaefacPXUeFHJaeoM7WE1gYAA1t0XgMwLGj+Gflb+xV58wj5qo3DE9CtGTKgXIHJ9iJNoYjnXG3msUbbXqH4w0ihHJOfhlXZZj4tFuIqwGUCkSyPyPunACIVyXo6qrD..KGu53YHsJMvLwi.9kbnE+HDioEiNJpxUd5BJBBcQKfrY7DIJRO3LtuCyCvWmiDZGx7OkGprg9Dwk7b4pjofrCiO8HmeA5oXLrldcfBJl8rF3x5K2.02zJ8YNXEdE6XgAuCsPDRckLBnt1S3FGRnX9AYO1E8FaBii.PQS8zNgx1.IQBobFLVfmCzO8PwXQK+liwhCzYryc.63yKe5XihykItjWKtTHMtLC8yLqzenAGWOj6gTyXm4UJCxntLWb0JllKATks3mG4lDiOl9jxKtvBKrbkkWdwUVzrZkUIQmF08Gs.KvuLX2n+aOyPQKNdtAJP0JlUpBBr5pqr3pKWwLti85skxvl.6cRFRA5Bn1Iu6CJyQeNOfGFo1LJmnSFjE90tiSnX3vunkeaPwoHKqdyPlR0rzbzPNz+5w3i4l0ZOrGgplDimASaeKk2avDaEouT8L18QEcGnMeXV0yJmkcYJM.Cc3v2BTyUx.WzoaNDOW8npiaj7SWenYFl8q5kFhpmitGBD.tHPG8oex55og4Ii14HR2CxVEoa6xfFmrujgHintG0TbzZ2i9BWDHvsU2S5YxW+50JPHh0uhTmn5F2xndKipFrnH0mawEmw6moyOpI+xIK+F.OLFmTrnGoZGN29DlUqT.dU00erVe2wG5wJgNKyw5tvzAdke4kechi0AJ23lWOJHoooQupx92L4lvX575iVDE57S8.ZYhm2qGLAWbbwH5c7azWa7yQ0JS0qY9DvXlRQ8M3p05tAGgqZwbRzJblubgeya9B+2Uqvu46wJ+yDmpbag+OjK7adag+aK7qCKlMgL07CqJ+8nyFoB+i8I5C1R+p2zyvBpETE+eeV6WCt9Vt3+PUvjrxjXzLXpovME8kktt7kdIH+xu8uyie9tQ6UX16s2lodex69KC4UjufejsTeIsHWp+j9MqR4xRkSGUlJYus9Sexe863Wtbzdgoo8.lw803MF7qMUC+LzMNI2H2PJa0lo97DSzWO8cxGSoMyxWdbbOk3gaF0LPppq5+tghz8vwkx98jUWsE1hisrxppKswElzMVcR23hS5FexjtwklzMt7jtwUt9Mh+CgDShi3cHor11JPngQRyoXqt+Of8WEUI

[ustk]

@whoopsydoodle Mmm, nothing weird here with that snippet...

[whoopsydoodle]

@ustk I am getting very strange results in DAW. I don't think it's jdelay. I think it's the tempo_sync node, or possibly something else.

It actually now looks fine in Plugin Doctor. If I set 300ms it's right on that and matches other delay plugins. But in Ableton I get this.

Top is the Ableton delay set to 300ms
Middle is this test set to 300ms
Bottom is this test except I replaced the jdelay with a delay node I made in Faust that has a negative sample offset from the value sent to it by the tempo node in Hise. I set that offset to -350samples. The project is at 44,1. If you look closely you can see that it's actually early on the first tap but then late on the later taps. I don't know what's going on.

[ustk]

@whoopsydoodle Very strange indeed! These alignements are weirdly misaligned...
the latest is in advance but then gets aligned later...

Are the different tests at least aligned with themselves if you repeat the operation? or is it random?

[whoopsydoodle]

@ustk I did a few further tests. It's not the tempo_sync node because taking it out and just manually setting the jdelay to a specific value gives the same result.

My best guess is there is some kind of compounding latency in the send receive nodes? I really don't know. All I can tell you is that the latency grows with each repeat. It's not a static amount that can be easily offset for.

I'm thinking it's time to call @Christoph-Hart on this one. It seems like it must be a deeper bug in scriptnode or something else.

[whoopsydoodle]

@whoopsydoodle Yep I just did further testing putting the whole feedback loop into a faust node instead of using hise for the feedback loop and the latency is gone. All repeats line up perfectly as they should.

It seems like there is a bug with the scriptnode send receive nodes that is causing latency to be added into the feedback signal.