daemon-conf: add remixing-use-all-sink-channels option

This option controls the PA_RESAMPLER_NO_FILL_SINK flag added in a
previous commit.

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=62588
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=94563

man/pulse-daemon.conf.5.xml.in

@@ -129,6 +129,14 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
       name-based matching only. Defaults to <opt>yes.</opt></p>
     </option>
 
+    <option>
+      <p><opt>remixing-use-all-sink-channels=</opt> If enabled, use
+      all sink channels when remixing. Otherwise, remix to the minimal
+      set of sink channels needed to reproduce all of the source
+      channels. (This has no effect on LFE remixing.) Defaults to
+      <opt>yes</opt>.</p>
+    </option>
+
     <option>
       <p><opt>enable-lfe-remixing=</opt> If disabled when upmixing or
       downmixing ignore LFE channels. When this option is disabled the

src/daemon/daemon-conf.c

@@ -82,6 +82,7 @@ static const pa_daemon_conf default_conf = {
     .log_time = false,
     .resample_method = PA_RESAMPLER_AUTO,
     .disable_remixing = false,
+    .remixing_use_all_sink_channels = true,
     .disable_lfe_remixing = true,
     .lfe_crossover_freq = 0,
     .config_file = NULL,
@@ -554,6 +555,8 @@ int pa_daemon_conf_load(pa_daemon_conf *c, const char *filename) {
         { "nice-level",                 parse_nice_level,         c, NULL },
         { "disable-remixing",           pa_config_parse_bool,     &c->disable_remixing, NULL },
         { "enable-remixing",            pa_config_parse_not_bool, &c->disable_remixing, NULL },
+        { "remixing-use-all-sink-channels",
+                                        pa_config_parse_bool,     &c->remixing_use_all_sink_channels, NULL },
         { "disable-lfe-remixing",       pa_config_parse_bool,     &c->disable_lfe_remixing, NULL },
         { "enable-lfe-remixing",        pa_config_parse_not_bool, &c->disable_lfe_remixing, NULL },
         { "lfe-crossover-freq",         pa_config_parse_unsigned, &c->lfe_crossover_freq, NULL },
@@ -748,6 +751,7 @@ char *pa_daemon_conf_dump(pa_daemon_conf *c) {
     pa_strbuf_printf(s, "log-level = %s\n", log_level_to_string[c->log_level]);
     pa_strbuf_printf(s, "resample-method = %s\n", pa_resample_method_to_string(c->resample_method));
     pa_strbuf_printf(s, "enable-remixing = %s\n", pa_yes_no(!c->disable_remixing));
+    pa_strbuf_printf(s, "remixing-use-all-sink-channels = %s\n", pa_yes_no(c->remixing_use_all_sink_channels));
     pa_strbuf_printf(s, "enable-lfe-remixing = %s\n", pa_yes_no(!c->disable_lfe_remixing));
     pa_strbuf_printf(s, "lfe-crossover-freq = %u\n", c->lfe_crossover_freq);
     pa_strbuf_printf(s, "default-sample-format = %s\n", pa_sample_format_to_string(c->default_sample_spec.format));

src/daemon/daemon-conf.h

@@ -68,6 +68,7 @@ typedef struct pa_daemon_conf {
         disable_shm,
         disable_memfd,
         disable_remixing,
+        remixing_use_all_sink_channels,
         disable_lfe_remixing,
         load_default_script_file,
         disallow_exit,

src/daemon/daemon.conf.in

@@ -55,6 +55,7 @@ ifelse(@HAVE_DBUS@, 1, [dnl
 
 ; resample-method = speex-float-1
 ; enable-remixing = yes
+; remixing-use-all-sink-channels = yes
 ; enable-lfe-remixing = no
 ; lfe-crossover-freq = 0
 

src/daemon/main.c

@@ -1037,6 +1037,7 @@ int main(int argc, char *argv[]) {
     c->realtime_priority = conf->realtime_priority;
     c->realtime_scheduling = conf->realtime_scheduling;
     c->disable_remixing = conf->disable_remixing;
+    c->remixing_use_all_sink_channels = conf->remixing_use_all_sink_channels;
     c->disable_lfe_remixing = conf->disable_lfe_remixing;
     c->deferred_volume = conf->deferred_volume;
     c->running_as_daemon = conf->daemonize;

src/pulsecore/core.c

@@ -142,6 +142,7 @@ pa_core* pa_core_new(pa_mainloop_api *m, bool shared, bool enable_memfd, size_t
     c->realtime_scheduling = false;
     c->realtime_priority = 5;
     c->disable_remixing = false;
+    c->remixing_use_all_sink_channels = true;
     c->disable_lfe_remixing = true;
     c->lfe_crossover_freq = 0;
     c->deferred_volume = true;

src/pulsecore/core.h

@@ -200,6 +200,7 @@ struct pa_core {
     bool running_as_daemon:1;
     bool realtime_scheduling:1;
     bool disable_remixing:1;
+    bool remixing_use_all_sink_channels:1;
     bool disable_lfe_remixing:1;
     bool deferred_volume:1;
 

src/pulsecore/sink-input.c

@@ -456,6 +456,7 @@ int pa_sink_input_new(
                           ((data->flags & PA_SINK_INPUT_VARIABLE_RATE) ? PA_RESAMPLER_VARIABLE_RATE : 0) |
                           ((data->flags & PA_SINK_INPUT_NO_REMAP) ? PA_RESAMPLER_NO_REMAP : 0) |
                           (core->disable_remixing || (data->flags & PA_SINK_INPUT_NO_REMIX) ? PA_RESAMPLER_NO_REMIX : 0) |
+                          (core->remixing_use_all_sink_channels ? 0 : PA_RESAMPLER_NO_FILL_SINK) |
                           (core->disable_lfe_remixing ? PA_RESAMPLER_NO_LFE : 0)))) {
                 pa_log_warn("Unsupported resampling operation.");
                 return -PA_ERR_NOTSUPPORTED;
@@ -2259,6 +2260,7 @@ int pa_sink_input_update_rate(pa_sink_input *i) {
                                      ((i->flags & PA_SINK_INPUT_VARIABLE_RATE) ? PA_RESAMPLER_VARIABLE_RATE : 0) |
                                      ((i->flags & PA_SINK_INPUT_NO_REMAP) ? PA_RESAMPLER_NO_REMAP : 0) |
                                      (i->core->disable_remixing || (i->flags & PA_SINK_INPUT_NO_REMIX) ? PA_RESAMPLER_NO_REMIX : 0) |
+                                     (i->core->remixing_use_all_sink_channels ? 0 : PA_RESAMPLER_NO_FILL_SINK) |
                                      (i->core->disable_lfe_remixing ? PA_RESAMPLER_NO_LFE : 0));
 
         if (!new_resampler) {

src/pulsecore/source-output.c

@@ -401,6 +401,7 @@ int pa_source_output_new(
                         ((data->flags & PA_SOURCE_OUTPUT_VARIABLE_RATE) ? PA_RESAMPLER_VARIABLE_RATE : 0) |
                         ((data->flags & PA_SOURCE_OUTPUT_NO_REMAP) ? PA_RESAMPLER_NO_REMAP : 0) |
                         (core->disable_remixing || (data->flags & PA_SOURCE_OUTPUT_NO_REMIX) ? PA_RESAMPLER_NO_REMIX : 0) |
+                        (core->remixing_use_all_sink_channels ? 0 : PA_RESAMPLER_NO_FILL_SINK) |
                         (core->disable_lfe_remixing ? PA_RESAMPLER_NO_LFE : 0)))) {
                 pa_log_warn("Unsupported resampling operation.");
                 return -PA_ERR_NOTSUPPORTED;
@@ -1714,6 +1715,7 @@ int pa_source_output_update_rate(pa_source_output *o) {
                                      ((o->flags & PA_SOURCE_OUTPUT_VARIABLE_RATE) ? PA_RESAMPLER_VARIABLE_RATE : 0) |
                                      ((o->flags & PA_SOURCE_OUTPUT_NO_REMAP) ? PA_RESAMPLER_NO_REMAP : 0) |
                                      (o->core->disable_remixing || (o->flags & PA_SOURCE_OUTPUT_NO_REMIX) ? PA_RESAMPLER_NO_REMIX : 0) |
+                                     (o->core->remixing_use_all_sink_channels ? 0 : PA_RESAMPLER_NO_FILL_SINK) |
                                      (o->core->disable_lfe_remixing ? PA_RESAMPLER_NO_LFE : 0));
 
         if (!new_resampler) {