Hi sorry, the correct word is probably sustain part, the post-attack-stable part of sound that you may be able to loop easily, for instance the quasi-steady state of a piano tone after the attack during the quasi-flat decay. Something found in archives presents very clearly the problem, and a possible implementation :
Let's suppose this is the sample: |-----SS-----LB-----LE------| where: SS= sample start (where we want the sample to start playing the first time) LB= loop begin LE= loop end
With appropriate calculations, the two phasors can be adjusted so that:
- Phasor A reproduces the sample the first time from SS to LE in its first
cycle. In subsequent cycles it would do the same but it will be muted so we don't mind. 2) Phasor B reproduces the loop region; its initial phase is calculated in such a way that at the beginning, when it is muted, it will be producing garbage, but when phasor A will reach point LB for the first time, phasor B will also be on LB, so that, during ONE cycle of phasor B, the two phasors will be reproducing *exactly* the same portion LB-LE synchronously.
So, at any moment of that cycle, we can (and we must) safely switch from the output of phasor A to that of phasor B; we don't need to do a crossfade because the two outputs are perfectly identical.
So, for detecting when to switch, we can use a [threshold~] on LB on the output of phasor A, even if threshold is block quantized. No matter if the actual switching occurs with a delay of almost one block, it will still be safe to switch.
... which seems brilliant ! (sorry i do not remember this contribution's author) Has this solution been implemented ? Is there an abstraction in a library addressing the same basic need ?
JM
Le 1 août 2012 à 18:54, Patrice Colet a écrit :
hello,
what is 'resonance part'?
in principle you compute the loop size in ms and send the result to [phasor~] or [vline~] for driving [tabread4~]
Colet Patrice
----- Mail original -----
De: "Jean-Marie Adrien" jma@jeanmarie-adrien.net À: "pd-list@iem.at List" pd-list@iem.at Envoyé: Mercredi 1 Août 2012 10:10:31 Objet: [PD] looping at the end of sample
Hi list have looked at the archives threads concerning managing the tabread4~'s index for reading an audio sample from the beginning and then loop on a chunk at the end (in the resonance part). Many things during the last years, but nothing very clear to me... Any patch around for playing sample from start and loop at the end ? Jm _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Allright, it seems you are looking for a crossfade loop implementation, that is quite usefull for looping audio in realtime, without getting clicks at loop point...
I might have something to start with, it's attached.
This patch uses cyclone objects because it has been originaly developped by a student using maxmsp native objects.
[trapezoid~] and [pong~] for crossfading with one phasor~ signal, and [wave~] for reading the wavefile.
I'm not sure about how to set the fading time, originaly expr was designed like this:
[expr 1./pow(2. ,$f1)]
The minimum table lenght is equal to loopsize + fadetime/2. [trapezoid~] makes the amplitude ramps, and [pong~] decays the ramps for reading both loopstart, and after loopend.
I'm still looking for pd-vanilla native implementation of this patch...
Colet Patrice
----- Mail original -----
De: "Jean-Marie Adrien" jma@jeanmarie-adrien.net À: "pd-list@iem.at List" pd-list@iem.at Envoyé: Jeudi 2 Août 2012 10:32:09 Objet: [PD] Rép : looping at the end of sample
Hi sorry, the correct word is probably sustain part, the post-attack-stable part of sound that you may be able to loop easily, for instance the quasi-steady state of a piano tone after the attack during the quasi-flat decay. Something found in archives presents very clearly the problem, and a possible implementation :
Let's suppose this is the sample: |-----SS-----LB-----LE------| where: SS= sample start (where we want the sample to start playing the first time) LB= loop begin LE= loop end
With appropriate calculations, the two phasors can be adjusted so that:
- Phasor A reproduces the sample the first time from SS to LE in its
first cycle. In subsequent cycles it would do the same but it will be muted so we don't mind. 2) Phasor B reproduces the loop region; its initial phase is calculated in such a way that at the beginning, when it is muted, it will be producing garbage, but when phasor A will reach point LB for the first time, phasor B will also be on LB, so that, during ONE cycle of phasor B, the two phasors will be reproducing *exactly* the same portion LB-LE synchronously.
So, at any moment of that cycle, we can (and we must) safely switch from the output of phasor A to that of phasor B; we don't need to do a crossfade because the two outputs are perfectly identical.
So, for detecting when to switch, we can use a [threshold~] on LB on the output of phasor A, even if threshold is block quantized. No matter if the actual switching occurs with a delay of almost one block, it will still be safe to switch.
... which seems brilliant ! (sorry i do not remember this contribution's author) Has this solution been implemented ? Is there an abstraction in a library addressing the same basic need ?
JM
Le 1 août 2012 à 18:54, Patrice Colet a écrit :
hello,
what is 'resonance part'?
in principle you compute the loop size in ms and send the result to [phasor~] or [vline~] for driving [tabread4~]
Colet Patrice
----- Mail original -----
De: "Jean-Marie Adrien" jma@jeanmarie-adrien.net À: "pd-list@iem.at List" pd-list@iem.at Envoyé: Mercredi 1 Août 2012 10:10:31 Objet: [PD] looping at the end of sample
Hi list have looked at the archives threads concerning managing the tabread4~'s index for reading an audio sample from the beginning and then loop on a chunk at the end (in the resonance part). Many things during the last years, but nothing very clear to me... Any patch around for playing sample from start and loop at the end ? Jm _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Thanks Patrice ! I was trying though to stick two loops without any amplitude ramp, just by being precise with the indexes on a single tabread4~ With some help, I solved the problem with a single loop~ object, plus samplehold~ to trigger window change : simple indeed. Could not manage synchronizing two phasors~ along many cycles with enough precision, due to 32bit computation of initial phase maybe. JM
Le 2 août 2012 à 19:53, Patrice Colet a écrit :
Allright, it seems you are looking for a crossfade loop implementation, that is quite usefull for looping audio in realtime, without getting clicks at loop point...
I might have something to start with, it's attached.
This patch uses cyclone objects because it has been originaly developped by a student using maxmsp native objects.
[trapezoid~] and [pong~] for crossfading with one phasor~ signal, and [wave~] for reading the wavefile.
I'm not sure about how to set the fading time, originaly expr was designed like this:
[expr 1./pow(2. ,$f1)]
The minimum table lenght is equal to loopsize + fadetime/2. [trapezoid~] makes the amplitude ramps, and [pong~] decays the ramps for reading both loopstart, and after loopend.
I'm still looking for pd-vanilla native implementation of this patch...
Colet Patrice
----- Mail original -----
De: "Jean-Marie Adrien" jma@jeanmarie-adrien.net À: "pd-list@iem.at List" pd-list@iem.at Envoyé: Jeudi 2 Août 2012 10:32:09 Objet: [PD] Rép : looping at the end of sample
Hi sorry, the correct word is probably sustain part, the post-attack-stable part of sound that you may be able to loop easily, for instance the quasi-steady state of a piano tone after the attack during the quasi-flat decay. Something found in archives presents very clearly the problem, and a possible implementation :
Let's suppose this is the sample: |-----SS-----LB-----LE------| where: SS= sample start (where we want the sample to start playing the first time) LB= loop begin LE= loop end
With appropriate calculations, the two phasors can be adjusted so that:
- Phasor A reproduces the sample the first time from SS to LE in its
first cycle. In subsequent cycles it would do the same but it will be muted so we don't mind. 2) Phasor B reproduces the loop region; its initial phase is calculated in such a way that at the beginning, when it is muted, it will be producing garbage, but when phasor A will reach point LB for the first time, phasor B will also be on LB, so that, during ONE cycle of phasor B, the two phasors will be reproducing *exactly* the same portion LB-LE synchronously.
So, at any moment of that cycle, we can (and we must) safely switch from the output of phasor A to that of phasor B; we don't need to do a crossfade because the two outputs are perfectly identical.
So, for detecting when to switch, we can use a [threshold~] on LB on the output of phasor A, even if threshold is block quantized. No matter if the actual switching occurs with a delay of almost one block, it will still be safe to switch.
... which seems brilliant ! (sorry i do not remember this contribution's author) Has this solution been implemented ? Is there an abstraction in a library addressing the same basic need ?
JM
Le 1 août 2012 à 18:54, Patrice Colet a écrit :
hello,
what is 'resonance part'?
in principle you compute the loop size in ms and send the result to [phasor~] or [vline~] for driving [tabread4~]
Colet Patrice
----- Mail original -----
De: "Jean-Marie Adrien" jma@jeanmarie-adrien.net À: "pd-list@iem.at List" pd-list@iem.at Envoyé: Mercredi 1 Août 2012 10:10:31 Objet: [PD] looping at the end of sample
Hi list have looked at the archives threads concerning managing the tabread4~'s index for reading an audio sample from the beginning and then loop on a chunk at the end (in the resonance part). Many things during the last years, but nothing very clear to me... Any patch around for playing sample from start and loop at the end ? Jm _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
<crossfadeLoop.pd>
-
Jean-Marie Adrien -
Patrice Colet