Currently loopback module indefinitely increased latency if underruns
occurs. This patch allows to set up the upper limit of latency.
---
src/modules/module-loopback.c | 34 ++++++++++++++++++++++++++++++----
1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/src/modules/module-loopback.c b/src/modules/module-loopback.c
index aecac0a..19005e8 100644
--- a/src/modules/module-loopback.c
+++ b/src/modules/module-loopback.c
@@ -45,6 +45,7 @@ PA_MODULE_USAGE(
"sink=<sink to connect to> "
"adjust_time=<how often to readjust rates in s> "
"latency_msec=<latency in ms> "
+ "max_latency_msec=<maximum latency in ms> "
"format=<sample format> "
"rate=<sample rate> "
"channels=<number of channels> "
@@ -89,6 +90,7 @@ struct userdata {
/* Values from command line configuration */
pa_usec_t latency;
+ pa_usec_t max_latency;
pa_usec_t adjust_time;
/* Latency boundaries and current values */
@@ -158,6 +160,7 @@ static const char* const valid_modargs[] = {
"sink",
"adjust_time",
"latency_msec",
+ "max_latency_msec",
"format",
"rate",
"channels",
@@ -325,10 +328,20 @@ static void adjust_rates(struct userdata *u) {
/* If we are seeing underruns then the latency is too small */
if (u->underrun_counter > 2) {
- u->underrun_latency_limit = PA_MAX(u->latency, u->minimum_latency) + 5
* PA_USEC_PER_MSEC;
- u->underrun_latency_limit = PA_CLIP_SUB((int64_t)u->underrun_latency_limit,
u->sink_latency_offset + u->source_latency_offset);
+ pa_usec_t target_latency;
+
+ target_latency = PA_MAX(u->latency, u->minimum_latency) + 5 *
PA_USEC_PER_MSEC;
+
+ if (u->max_latency == 0 || target_latency < u->max_latency) {
+ u->underrun_latency_limit = PA_CLIP_SUB((int64_t)target_latency,
u->sink_latency_offset + u->source_latency_offset);
+ pa_log_warn("Too many underruns, increasing latency to %0.2f ms",
(double)target_latency / PA_USEC_PER_MSEC);
+ } else {
+ u->underrun_latency_limit = PA_CLIP_SUB((int64_t)u->max_latency,
u->sink_latency_offset + u->source_latency_offset);
+ pa_log_warn("Too many underruns, configured maximum latency of %0.2f ms is
reached", (double)u->max_latency / PA_USEC_PER_MSEC);
+ pa_log_warn("Consider increasing the max_latency_msec");
+ }
+
update_minimum_latency(u, u->sink_input->sink, false);
- pa_log_warn("Too many underruns, increasing latency to %0.2f ms",
(double)u->minimum_latency / PA_USEC_PER_MSEC);
u->underrun_counter = 0;
}
@@ -347,7 +360,7 @@ static void adjust_rates(struct userdata *u) {
}
u->adjust_time_stamp = now;
- /* Rates and latencies*/
+ /* Rates and latencies */
old_rate = u->sink_input->sample_spec.rate;
base_rate = u->source_output->sample_spec.rate;
@@ -1252,6 +1265,7 @@ int pa__init(pa_module *m) {
pa_source_output_new_data source_output_data;
bool source_dont_move;
uint32_t latency_msec;
+ uint32_t max_latency_msec;
pa_sample_spec ss;
pa_channel_map map;
bool format_set = false;
@@ -1336,10 +1350,22 @@ int pa__init(pa_module *m) {
goto fail;
}
+ max_latency_msec = 0;
+ if (pa_modargs_get_value_u32(ma, "max_latency_msec", &max_latency_msec) <
0) {
+ pa_log("Invalid maximum latency specification");
+ goto fail;
+ }
+
+ if (max_latency_msec > 0 && max_latency_msec < latency_msec) {
+ pa_log_warn("Configured maximum latency is smaller than latency, using
latency instead");
+ max_latency_msec = latency_msec;
+ }
+
m->userdata = u = pa_xnew0(struct userdata, 1);
u->core = m->core;
u->module = m;
u->latency = (pa_usec_t) latency_msec * PA_USEC_PER_MSEC;
+ u->max_latency = (pa_usec_t) max_latency_msec * PA_USEC_PER_MSEC;
u->output_thread_info.pop_called = false;
u->output_thread_info.pop_adjust = false;
u->output_thread_info.push_called = false;
