From 572a69758a76e0c713444df248658ce84a9c4c5c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 19 Jul 2021 17:28:25 +0200
Subject: [PATCH] Min playback speed is +/- (100/16)%

This is for at least two reasons: transport will effectively
move with 32 samples * 6.25% = 2 samples per cycle and the
resampler cannot up/downsample a factor of > 16 with
reasonable quality.
---
 libs/ardour/session_transport.cc | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index 82576f019f..2dcd02a877 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -321,6 +321,15 @@ Session::default_play_speed ()
 void
 Session::set_default_play_speed (double spd)
 {
+	/* see also Port::set_speed_ratio and
+	 * VMResampler::set_rratio() for min/max range.
+	 * speed must be > +/- 100 / 16 %
+	 */
+	if (spd > 0.0) {
+		spd = std::min<double> (Config->get_max_transport_speed(), std::max (0.0625, spd));
+	} else if (spd < 0.0) {
+		spd = std::max<double> (- Config->get_max_transport_speed(), std::min (-0.0625, spd));
+	}
 	_transport_fsm->set_default_speed(spd);
 	TFSM_SPEED(spd);
 	TransportStateChange (); /* EMIT SIGNAL */