From 0efae0488ccd4536926f5fa2b4cf524e63da9095 Mon Sep 17 00:00:00 2001 From: Georg Chini Date: Mon, 4 Jan 2021 21:08:05 +0100 Subject: [PATCH] loopback: Fix sink latency calculation if source is alsa source with fixed latency When an alsa source with fixed latency is used, the actual latency of the source will only be one fragment size. This is not taken into account when the required sink latency is calculated. This patch fixes the issue. Part-of: --- src/modules/module-loopback.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/modules/module-loopback.c b/src/modules/module-loopback.c index 871f011..4f8ceec 100644 --- a/src/modules/module-loopback.c +++ b/src/modules/module-loopback.c @@ -1016,6 +1016,14 @@ static void set_sink_input_latency(struct userdata *u, pa_sink *sink) { if (u->min_source_latency > requested_latency) { latency = PA_MAX(u->latency, u->minimum_latency); requested_latency = (latency - u->min_source_latency) / 2; + /* In the case of a fixed alsa source, u->minimum_latency is calculated from + * the default fragment size while u->min_source_latency is the reported minimum + * of the source latency (nr_of_fragments * fragment_size). This can lead to a + * situation where u->minimum_latency < u->min_source_latency. We only fall + * back to use the fragment size instead of min_source_latency if the calculation + * above does not deliver a usable result. */ + if (u->fixed_alsa_source && u->min_source_latency >= latency) + requested_latency = (latency - u->core->default_fragment_size_msec * PA_USEC_PER_MSEC) / 2; } latency = PA_CLAMP(requested_latency , u->min_sink_latency, u->max_sink_latency); -- 2.7.4