loopback: Enable routing on loopback streams

At module-loopback load, if no sink is given, the default sink is used. If the
stream has a media.role property, the property cannot be used because a the
source or sink is forced to default. Both module-intended-roles and
module-device-manager are affected. The same apply to sources.

With this patch, if sink or source is missing, routing modules can be used.

1 files changed, 89 insertions, 26 deletions

diff --git a/src/modules/module-loopback.c b/src/modules/module-loopback.c
index 1a69445f..9054700c 100644
--- a/src/modules/module-loopback.c
+++ b/src/modules/module-loopback.c
@@ -647,15 +647,18 @@ static pa_bool_t sink_input_may_move_to_cb(pa_sink_input *i, pa_sink *dest) {
 int pa__init(pa_module *m) {
     pa_modargs *ma = NULL;
     struct userdata *u;
-    pa_sink *sink;
+    pa_sink *sink = NULL;
     pa_sink_input_new_data sink_input_data;
     pa_bool_t sink_dont_move;
-    pa_source *source;
+    pa_source *source = NULL;
     pa_source_output_new_data source_output_data;
     pa_bool_t source_dont_move;
     uint32_t latency_msec;
     pa_sample_spec ss;
     pa_channel_map map;
+    bool format_set = false;
+    bool rate_set = false;
+    bool channels_set = false;
     pa_memchunk silence;
     uint32_t adjust_time_sec;
     const char *n;
@@ -668,12 +671,14 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
-    if (!(source = pa_namereg_get(m->core, pa_modargs_get_value(ma, "source", NULL), PA_NAMEREG_SOURCE))) {
+    n = pa_modargs_get_value(ma, "source", NULL);
+    if (n && !(source = pa_namereg_get(m->core, n, PA_NAMEREG_SOURCE))) {
         pa_log("No such source.");
         goto fail;
     }
 
-    if (!(sink = pa_namereg_get(m->core, pa_modargs_get_value(ma, "sink", NULL), PA_NAMEREG_SINK))) {
+    n = pa_modargs_get_value(ma, "sink", NULL);
+    if (n && !(sink = pa_namereg_get(m->core, n, PA_NAMEREG_SINK))) {
         pa_log("No such sink.");
         goto fail;
     }
@@ -683,13 +688,45 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
-    ss = sink->sample_spec;
-    map = sink->channel_map;
+    if (sink) {
+        ss = sink->sample_spec;
+        map = sink->channel_map;
+        format_set = true;
+        rate_set = true;
+        channels_set = true;
+    } else if (source) {
+        ss = source->sample_spec;
+        map = source->channel_map;
+        format_set = true;
+        rate_set = true;
+        channels_set = true;
+    } else {
+        /* FIXME: Dummy stream format, needed because pa_sink_input_new()
+         * requires valid sample spec and channel map even when all the FIX_*
+         * stream flags are specified. pa_sink_input_new() should be changed
+         * to ignore the sample spec and channel map when the FIX_* flags are
+         * present. */
+        ss.format = PA_SAMPLE_U8;
+        ss.rate = 8000;
+        ss.channels = 1;
+        map.channels = 1;
+        map.map[0] = PA_CHANNEL_POSITION_MONO;
+    }
+
     if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
         pa_log("Invalid sample format specification or channel map");
         goto fail;
     }
 
+    if (pa_modargs_get_value(ma, "format", NULL))
+        format_set = true;
+
+    if (pa_modargs_get_value(ma, "rate", NULL))
+        rate_set = true;
+
+    if (pa_modargs_get_value(ma, "channels", NULL) || pa_modargs_get_value(ma, "channel_map", NULL))
+        channels_set = true;
+
     latency_msec = DEFAULT_LATENCY_MSEC;
     if (pa_modargs_get_value_u32(ma, "latency_msec", &latency_msec) < 0 || latency_msec < 1 || latency_msec > 2000) {
         pa_log("Invalid latency specification");
@@ -715,7 +752,9 @@ int pa__init(pa_module *m) {
     pa_sink_input_new_data_init(&sink_input_data);
     sink_input_data.driver = __FILE__;
     sink_input_data.module = m;
-    pa_sink_input_new_data_set_sink(&sink_input_data, sink, FALSE);
+
+    if (sink)
+        pa_sink_input_new_data_set_sink(&sink_input_data, sink, FALSE);
 
     if (pa_modargs_get_proplist(ma, "sink_input_properties", sink_input_data.proplist, PA_UPDATE_REPLACE) < 0) {
         pa_log("Failed to parse the sink_input_properties value.");
@@ -723,20 +762,24 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
-    if (!pa_proplist_contains(sink_input_data.proplist, PA_PROP_MEDIA_NAME))
-        pa_proplist_setf(sink_input_data.proplist, PA_PROP_MEDIA_NAME, "Loopback from %s",
-                         pa_strnull(pa_proplist_gets(source->proplist, PA_PROP_DEVICE_DESCRIPTION)));
-
     if (!pa_proplist_contains(sink_input_data.proplist, PA_PROP_MEDIA_ROLE))
         pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_ROLE, "abstract");
 
-    if (!pa_proplist_contains(sink_input_data.proplist, PA_PROP_MEDIA_ICON_NAME)
-            && (n = pa_proplist_gets(source->proplist, PA_PROP_DEVICE_ICON_NAME)))
-        pa_proplist_sets(sink_input_data.proplist, PA_PROP_MEDIA_ICON_NAME, n);
-
     pa_sink_input_new_data_set_sample_spec(&sink_input_data, &ss);
     pa_sink_input_new_data_set_channel_map(&sink_input_data, &map);
-    sink_input_data.flags = PA_SINK_INPUT_VARIABLE_RATE | (remix ? 0 : PA_SINK_INPUT_NO_REMIX);
+    sink_input_data.flags = PA_SINK_INPUT_VARIABLE_RATE;
+
+    if (!remix)
+        sink_input_data.flags |= PA_SINK_INPUT_NO_REMIX;
+
+    if (!format_set)
+        sink_input_data.flags |= PA_SINK_INPUT_FIX_FORMAT;
+
+    if (!rate_set)
+        sink_input_data.flags |= PA_SINK_INPUT_FIX_RATE;
+
+    if (!channels_set)
+        sink_input_data.flags |= PA_SINK_INPUT_FIX_CHANNELS;
 
     sink_dont_move = FALSE;
     if (pa_modargs_get_value_boolean(ma, "sink_dont_move", &sink_dont_move) < 0) {
@@ -770,7 +813,8 @@ int pa__init(pa_module *m) {
     pa_source_output_new_data_init(&source_output_data);
     source_output_data.driver = __FILE__;
     source_output_data.module = m;
-    pa_source_output_new_data_set_source(&source_output_data, source, FALSE);
+    if (source)
+        pa_source_output_new_data_set_source(&source_output_data, source, FALSE);
 
     if (pa_modargs_get_proplist(ma, "source_output_properties", source_output_data.proplist, PA_UPDATE_REPLACE) < 0) {
         pa_log("Failed to parse the source_output_properties value.");
@@ -778,20 +822,23 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
-    if (!pa_proplist_contains(source_output_data.proplist, PA_PROP_MEDIA_NAME))
-        pa_proplist_setf(source_output_data.proplist, PA_PROP_MEDIA_NAME, "Loopback to %s",
-                         pa_strnull(pa_proplist_gets(sink->proplist, PA_PROP_DEVICE_DESCRIPTION)));
-
     if (!pa_proplist_contains(source_output_data.proplist, PA_PROP_MEDIA_ROLE))
         pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_ROLE, "abstract");
 
-    if (!pa_proplist_contains(source_output_data.proplist, PA_PROP_MEDIA_ICON_NAME)
-            && (n = pa_proplist_gets(sink->proplist, PA_PROP_DEVICE_ICON_NAME)))
-        pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_ICON_NAME, n);
-
     pa_source_output_new_data_set_sample_spec(&source_output_data, &ss);
     pa_source_output_new_data_set_channel_map(&source_output_data, &map);
-    source_output_data.flags = (remix ? 0 : PA_SOURCE_OUTPUT_NO_REMIX);
+
+    if (!remix)
+        source_output_data.flags |= PA_SOURCE_OUTPUT_NO_REMIX;
+
+    if (!format_set)
+        source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_FORMAT;
+
+    if (!rate_set)
+        source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_RATE;
+
+    if (!channels_set)
+        source_output_data.flags |= PA_SOURCE_OUTPUT_FIX_CHANNELS;
 
     source_dont_move = FALSE;
     if (pa_modargs_get_value_boolean(ma, "source_dont_move", &source_dont_move) < 0) {
@@ -836,6 +883,22 @@ int pa__init(pa_module *m) {
 
     u->asyncmsgq = pa_asyncmsgq_new(0);
 
+    if (!pa_proplist_contains(u->source_output->proplist, PA_PROP_MEDIA_NAME))
+        pa_proplist_setf(u->source_output->proplist, PA_PROP_MEDIA_NAME, "Loopback to %s",
+                         pa_strnull(pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_DESCRIPTION)));
+
+    if (!pa_proplist_contains(u->source_output->proplist, PA_PROP_MEDIA_ICON_NAME)
+            && (n = pa_proplist_gets(u->sink_input->sink->proplist, PA_PROP_DEVICE_ICON_NAME)))
+        pa_proplist_sets(u->source_output->proplist, PA_PROP_MEDIA_ICON_NAME, n);
+
+    if (!pa_proplist_contains(u->sink_input->proplist, PA_PROP_MEDIA_NAME))
+        pa_proplist_setf(u->sink_input->proplist, PA_PROP_MEDIA_NAME, "Loopback from %s",
+                         pa_strnull(pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_DESCRIPTION)));
+
+    if (source && !pa_proplist_contains(u->sink_input->proplist, PA_PROP_MEDIA_ICON_NAME)
+            && (n = pa_proplist_gets(u->source_output->source->proplist, PA_PROP_DEVICE_ICON_NAME)))
+        pa_proplist_sets(u->sink_input->proplist, PA_PROP_MEDIA_ICON_NAME, n);
+
     pa_sink_input_put(u->sink_input);
     pa_source_output_put(u->source_output);