[pulseaudio-discuss] [PATCH v4 23/23] echo-cancel: Add beamforming support in the webrtc canceller
arun at accosted.net
arun at accosted.net
Wed Feb 17 14:17:15 UTC 2016
From: Arun Raghavan <git at arunraghavan.net>
---
src/modules/echo-cancel/webrtc.cc | 152 +++++++++++++++++++++++++++++++++++++-
1 file changed, 148 insertions(+), 4 deletions(-)
diff --git a/src/modules/echo-cancel/webrtc.cc b/src/modules/echo-cancel/webrtc.cc
index ead7884..45ba00f 100644
--- a/src/modules/echo-cancel/webrtc.cc
+++ b/src/modules/echo-cancel/webrtc.cc
@@ -53,6 +53,7 @@ PA_C_DECL_END
#define DEFAULT_INTELLIGIBILITY_ENHANCER false
#define DEFAULT_EXPERIMENTAL_AGC false
#define DEFAULT_AGC_START_VOLUME 85
+#define DEFAULT_BEAMFORMING false
#define DEFAULT_TRACE false
#define WEBRTC_AGC_MAX_VOLUME 255
@@ -71,6 +72,9 @@ static const char* const valid_modargs[] = {
"intelligibility_enhancer",
"experimental_agc",
"agc_start_volume",
+ "beamforming",
+ "mic_geometry", /* documented in parse_mic_geometry() */
+ "target_direction", /* documented in parse_mic_geometry() */
"trace",
NULL
};
@@ -116,7 +120,8 @@ static pa_volume_t webrtc_volume_to_pa(int v)
static void webrtc_ec_fixate_spec(pa_sample_spec *rec_ss, pa_channel_map *rec_map,
pa_sample_spec *play_ss, pa_channel_map *play_map,
- pa_sample_spec *out_ss, pa_channel_map *out_map)
+ pa_sample_spec *out_ss, pa_channel_map *out_map,
+ bool beamforming)
{
rec_ss->format = PA_SAMPLE_FLOAT32NE;
play_ss->format = PA_SAMPLE_FLOAT32NE;
@@ -131,14 +136,100 @@ static void webrtc_ec_fixate_spec(pa_sample_spec *rec_ss, pa_channel_map *rec_ma
else
rec_ss->rate = 8000;
- /* In int16 mode, AudioProcessing will give us the same spec we give it */
*out_ss = *rec_ss;
*out_map = *rec_map;
+ if (beamforming) {
+ /* The beamformer gives us a single channel */
+ out_ss->channels = 1;
+ pa_channel_map_init_mono(out_map);
+ }
+
/* Playback stream rate needs to be the same as capture */
play_ss->rate = rec_ss->rate;
}
+static bool parse_point(const char **point, float (&f)[3]) {
+ int ret, length;
+
+ ret = sscanf(*point, "%g,%g,%g%n", &f[0], &f[1], &f[2], &length);
+ if (ret != 3)
+ return false;
+
+ /* Consume the bytes we've read so far */
+ *point += length;
+
+ return true;
+}
+
+static bool parse_mic_geometry(const char **mic_geometry, std::vector<webrtc::Point>& geometry) {
+ /* The microphone geometry is expressed as cartesian point form:
+ * x1,y1,z1,x2,y2,z2,...
+ *
+ * Where x1,y1,z1 is the position of the first microphone with regards to
+ * the array's "center", x2,y2,z2 the position of the second, and so on.
+ *
+ * 'x' is the horizontal coordinate, with positive values being to the
+ * right from the mic array's perspective.
+ *
+ * 'y' is the depth coordinate, with positive values being in front of the
+ * array.
+ *
+ * 'z' is the vertical coordinate, with positive values being above the
+ * array.
+ *
+ * All distances are in meters.
+ */
+
+ /* The target direction is expected to be in spherical point form:
+ * a,e,r
+ *
+ * Where 'a is the azimuth of the first mic channel, 'e' its elevation,
+ * and 'r' the radius.
+ *
+ * 0 radians azimuth is to the right of the array, and positive angles
+ * move in a counter-clockwise direction.
+ *
+ * 0 radians elevation is horizontal w.r.t. the array, and positive
+ * angles go upwards.
+ *
+ * radius is distance from the array center in meters.
+ */
+
+ int i;
+ float f[3];
+
+ for (i = 0; i < geometry.size(); i++) {
+ if (!parse_point(mic_geometry, f)) {
+ pa_log("Failed to parse channel %d in mic_geometry", i);
+ return false;
+ }
+
+ /* Except for the last point, we should have a trailing comma */
+ if (i != geometry.size() - 1) {
+ if (**mic_geometry != ',') {
+ pa_log("Failed to parse channel %d in mic_geometry", i);
+ return false;
+ }
+
+ (*mic_geometry)++;
+ }
+
+ pa_log_debug("Got mic #%d position: (%g, %g, %g)", i, f[0], f[1], f[2]);
+
+ geometry[i].c[0] = f[0];
+ geometry[i].c[1] = f[1];
+ geometry[i].c[2] = f[2];
+ }
+
+ if (**mic_geometry != '\0') {
+ pa_log("Failed to parse mic_geometry value: more parameters than expected");
+ return false;
+ }
+
+ return true;
+}
+
bool pa_webrtc_ec_init(pa_core *c, pa_echo_canceller *ec,
pa_sample_spec *rec_ss, pa_channel_map *rec_map,
pa_sample_spec *play_ss, pa_channel_map *play_map,
@@ -147,7 +238,7 @@ bool pa_webrtc_ec_init(pa_core *c, pa_echo_canceller *ec,
webrtc::AudioProcessing *apm = NULL;
webrtc::ProcessingConfig pconfig;
webrtc::Config config;
- bool hpf, ns, agc, dgc, mobile, cn, vad, ext_filter, intelligibility, experimental_agc;
+ bool hpf, ns, agc, dgc, mobile, cn, vad, ext_filter, intelligibility, experimental_agc, beamforming;
int rm = -1, i;
uint32_t agc_start_volume;
pa_modargs *ma;
@@ -257,6 +348,12 @@ bool pa_webrtc_ec_init(pa_core *c, pa_echo_canceller *ec,
}
ec->params.webrtc.agc_start_volume = agc_start_volume;
+ beamforming = DEFAULT_BEAMFORMING;
+ if (pa_modargs_get_value_boolean(ma, "beamforming", &beamforming) < 0) {
+ pa_log("Failed to parse beamforming value");
+ goto fail;
+ }
+
if (ext_filter)
config.Set<webrtc::ExtendedFilter>(new webrtc::ExtendedFilter(true));
if (intelligibility)
@@ -277,7 +374,54 @@ bool pa_webrtc_ec_init(pa_core *c, pa_echo_canceller *ec,
webrtc::Trace::SetTraceCallback((PaWebrtcTraceCallback *) ec->params.webrtc.trace_callback);
}
- webrtc_ec_fixate_spec(rec_ss, rec_map, play_ss, play_map, out_ss, out_map);
+ webrtc_ec_fixate_spec(rec_ss, rec_map, play_ss, play_map, out_ss, out_map, beamforming);
+
+ /* We do this after fixate because we need the capture channel count */
+ if (beamforming) {
+ std::vector<webrtc::Point> geometry(rec_ss->channels);
+ webrtc::SphericalPointf direction(0.0f, 0.0f, 0.0f);
+ const char *mic_geometry, *target_direction;
+
+ if (!(mic_geometry = pa_modargs_get_value(ma, "mic_geometry", NULL))) {
+ pa_log("mic_geometry must be set if beamforming is enabled");
+ goto fail;
+ }
+
+ if (!parse_mic_geometry(&mic_geometry, geometry)) {
+ pa_log("Failed to parse mic_geometry value");
+ goto fail;
+ }
+
+ if ((target_direction = pa_modargs_get_value(ma, "target_direction", NULL))) {
+ float f[3];
+
+ if (!parse_point(&target_direction, f)) {
+ pa_log("Failed to parse target_direction value");
+ goto fail;
+ }
+
+ if (*target_direction != '\0') {
+ pa_log("Failed to parse target_direction value: more parameters than expected");
+ goto fail;
+ }
+
+#define IS_ZERO(f) ((f) < 0.000001 && (f) > -0.000001)
+
+ if (!IS_ZERO(f[1]) || !IS_ZERO(f[2])) {
+ pa_log("The beamformer currently only supports targeting along the azimuth");
+ goto fail;
+ }
+
+ direction.s[0] = f[0];
+ direction.s[1] = f[1];
+ direction.s[2] = f[2];
+ }
+
+ if (!target_direction)
+ config.Set<webrtc::Beamforming>(new webrtc::Beamforming(true, geometry));
+ else
+ config.Set<webrtc::Beamforming>(new webrtc::Beamforming(true, geometry, direction));
+ }
apm = webrtc::AudioProcessing::Create(config);
--
2.5.0
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