From 4693028b9b706616b43d058e3b165d13090b1aff Mon Sep 17 00:00:00 2001
From: Arun Raghavan <arun@asymptotic.io>
Date: Wed, 12 Jan 2022 13:22:34 -0500
Subject: [PATCH] sink, source: Add API to change channel count

This makes this part symmetrical with the rest of the sample spec, and
will be useful when we implement switching channel count in a sink.
---
 src/pulsecore/sink.c   | 18 ++++++++++++++++++
 src/pulsecore/sink.h   |  1 +
 src/pulsecore/source.c | 18 ++++++++++++++++++
 src/pulsecore/source.h |  1 +
 4 files changed, 38 insertions(+)

diff --git a/src/pulsecore/sink.c b/src/pulsecore/sink.c
index 43a12f390..f6d15b9e3 100644
--- a/src/pulsecore/sink.c
+++ b/src/pulsecore/sink.c
@@ -4083,6 +4083,24 @@ void pa_sink_set_sample_rate(pa_sink *s, uint32_t rate) {
     pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK | PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
 }
 
+/* Called from the main thread */
+void pa_sink_set_channels(pa_sink *s, uint8_t channels) {
+    uint8_t old_channels;
+
+    pa_assert(s);
+    pa_assert(pa_channels_valid(channels));
+
+    old_channels = s->sample_spec.channels;
+    if (old_channels == channels)
+        return;
+
+    pa_log_info("%s: channels: %u -> %u", s->name, old_channels, channels);
+
+    s->sample_spec.channels = channels;
+
+    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK | PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+}
+
 /* Called from the main thread */
 void pa_sink_set_channel_map(pa_sink *s, pa_channel_map *map) {
     pa_channel_map old_map;
diff --git a/src/pulsecore/sink.h b/src/pulsecore/sink.h
index 764721a55..9ff68c877 100644
--- a/src/pulsecore/sink.h
+++ b/src/pulsecore/sink.h
@@ -529,6 +529,7 @@ pa_idxset* pa_sink_check_formats(pa_sink *s, pa_idxset *in_formats);
 
 void pa_sink_set_sample_format(pa_sink *s, pa_sample_format_t format);
 void pa_sink_set_sample_rate(pa_sink *s, uint32_t rate);
+void pa_sink_set_channels(pa_sink *s, uint8_t channels);
 void pa_sink_set_channel_map(pa_sink *s, pa_channel_map *map);
 
 /*** To be called exclusively by the sink driver, from IO context */
diff --git a/src/pulsecore/source.c b/src/pulsecore/source.c
index d3ed57254..58e4e458a 100644
--- a/src/pulsecore/source.c
+++ b/src/pulsecore/source.c
@@ -3077,6 +3077,24 @@ void pa_source_set_sample_rate(pa_source *s, uint32_t rate) {
     pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE | PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
 }
 
+/* Called from the main thread */
+void pa_source_set_channels(pa_source *s, uint8_t channels) {
+    uint8_t old_channels;
+
+    pa_assert(s);
+    pa_assert(pa_channels_valid(channels));
+
+    old_channels = s->sample_spec.channels;
+    if (old_channels == channels)
+        return;
+
+    pa_log_info("%s: channels: %u -> %u", s->name, old_channels, channels);
+
+    s->sample_spec.channels = channels;
+
+    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE | PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+}
+
 /* Called from the main thread */
 void pa_source_set_channel_map(pa_source *s, pa_channel_map *map) {
     pa_channel_map old_map;
diff --git a/src/pulsecore/source.h b/src/pulsecore/source.h
index 64ea11f9d..8c67b2d4b 100644
--- a/src/pulsecore/source.h
+++ b/src/pulsecore/source.h
@@ -450,6 +450,7 @@ pa_idxset* pa_source_check_formats(pa_source *s, pa_idxset *in_formats);
 
 void pa_source_set_sample_format(pa_source *s, pa_sample_format_t format);
 void pa_source_set_sample_rate(pa_source *s, uint32_t rate);
+void pa_source_set_channels(pa_source *s, uint8_t channels);
 void pa_source_set_channel_map(pa_source *s, pa_channel_map *map);
 
 /*** To be called exclusively by the source driver, from IO context */