[pulseaudio-discuss] [PATCH v2 2/4] resampler: Flag for remixing to all sink channels.
david at mandelberg.org
david at mandelberg.org
Wed Jan 4 16:55:47 UTC 2017
From: David Mandelberg <dseomn at google.com>
Add a flag PA_RESAMPLER_NO_FILL_SINK, which controls whether remixing
should attempt to use all sink channels, versus only the ones needed
to reproduce the source audio.
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=62588
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=94563
Suggested-by: Alexander E. Patrakov <patrakov at gmail.com>
---
src/pulsecore/resampler.c | 82 +++++++++++++++++++++++++++++++++++++++++------
src/pulsecore/resampler.h | 3 +-
2 files changed, 75 insertions(+), 10 deletions(-)
diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c
index ea22cd2..063c4c5 100644
--- a/src/pulsecore/resampler.c
+++ b/src/pulsecore/resampler.c
@@ -796,6 +796,64 @@ static int front_rear_side(pa_channel_position_t p) {
return ON_OTHER;
}
+/* Fill a map of which output channels should get mono from input, not including
+ * LFE output channels. (The LFE output channels are mapped separately.)
+ */
+static void setup_oc_mono_map(const pa_resampler *r, float *oc_mono_map) {
+ unsigned oc;
+ unsigned n_oc;
+ bool found_oc_for_mono = false;
+
+ pa_assert(r);
+ pa_assert(oc_mono_map);
+
+ n_oc = r->o_ss.channels;
+
+ if (!(r->flags & PA_RESAMPLER_NO_FILL_SINK)) {
+ /* Mono goes to all non-LFE output channels and we're done. */
+ for (oc = 0; oc < n_oc; oc++)
+ oc_mono_map[oc] = on_lfe(r->o_cm.map[oc]) ? 0.0f : 1.0f;
+ return;
+ } else {
+ /* Initialize to all zero so we can select individual channels below. */
+ for (oc = 0; oc < n_oc; oc++)
+ oc_mono_map[oc] = 0.0f;
+ }
+
+ for (oc = 0; oc < n_oc; oc++) {
+ if (r->o_cm.map[oc] == PA_CHANNEL_POSITION_MONO) {
+ oc_mono_map[oc] = 1.0f;
+ found_oc_for_mono = true;
+ }
+ }
+ if (found_oc_for_mono)
+ return;
+
+ for (oc = 0; oc < n_oc; oc++) {
+ if (r->o_cm.map[oc] == PA_CHANNEL_POSITION_FRONT_CENTER) {
+ oc_mono_map[oc] = 1.0f;
+ found_oc_for_mono = true;
+ }
+ }
+ if (found_oc_for_mono)
+ return;
+
+ for (oc = 0; oc < n_oc; oc++) {
+ if (r->o_cm.map[oc] == PA_CHANNEL_POSITION_FRONT_LEFT || r->o_cm.map[oc] == PA_CHANNEL_POSITION_FRONT_RIGHT) {
+ oc_mono_map[oc] = 1.0f;
+ found_oc_for_mono = true;
+ }
+ }
+ if (found_oc_for_mono)
+ return;
+
+ /* Give up on finding a suitable map for mono, and just send it to all
+ * non-LFE output channels.
+ */
+ for (oc = 0; oc < n_oc; oc++)
+ oc_mono_map[oc] = on_lfe(r->o_cm.map[oc]) ? 0.0f : 1.0f;
+}
+
static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed) {
unsigned oc, ic;
unsigned n_oc, n_ic;
@@ -858,14 +916,14 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
* 1) Connect all channels with matching names.
*
* 2) Mono Handling:
- * S:Mono: Copy into all D:channels
+ * S:Mono: See setup_oc_mono_map().
* D:Mono: Avg all S:channels
*
- * 3) Mix D:Left, D:Right:
+ * 3) Mix D:Left, D:Right (if PA_RESAMPLER_NO_FILL_SINK is clear):
* D:Left: If not connected, avg all S:Left
* D:Right: If not connected, avg all S:Right
*
- * 4) Mix D:Center
+ * 4) Mix D:Center (if PA_RESAMPLER_NO_FILL_SINK is clear):
* If not connected, avg all S:Center
* If still not connected, avg all S:Left, S:Right
*
@@ -908,6 +966,7 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
ic_unconnected_center = 0,
ic_unconnected_lfe = 0;
bool ic_unconnected_center_mixed_in = 0;
+ float oc_mono_map[PA_CHANNELS_MAX];
for (ic = 0; ic < n_ic; ic++) {
if (on_left(r->i_cm.map[ic]))
@@ -918,6 +977,8 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
ic_center++;
}
+ setup_oc_mono_map(r, oc_mono_map);
+
for (oc = 0; oc < n_oc; oc++) {
bool oc_connected = false;
pa_channel_position_t b = r->o_cm.map[oc];
@@ -925,14 +986,17 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
for (ic = 0; ic < n_ic; ic++) {
pa_channel_position_t a = r->i_cm.map[ic];
- if (a == b || a == PA_CHANNEL_POSITION_MONO) {
+ if (a == b) {
m->map_table_f[oc][ic] = 1.0f;
oc_connected = true;
ic_connected[ic] = true;
+ }
+ else if (a == PA_CHANNEL_POSITION_MONO && oc_mono_map[oc] > 0.0f) {
+ m->map_table_f[oc][ic] = oc_mono_map[oc];
- if (a == PA_CHANNEL_POSITION_MONO && on_lfe(b) && !(r->flags & PA_RESAMPLER_NO_LFE))
- *lfe_remixed = true;
+ oc_connected = true;
+ ic_connected[ic] = true;
}
else if (b == PA_CHANNEL_POSITION_MONO) {
m->map_table_f[oc][ic] = 1.0f / (float) n_ic;
@@ -945,7 +1009,7 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
if (!oc_connected) {
/* Try to find matching input ports for this output port */
- if (on_left(b)) {
+ if (on_left(b) && !(r->flags & PA_RESAMPLER_NO_FILL_SINK)) {
/* We are not connected and on the left side, let's
* average all left side input channels. */
@@ -960,7 +1024,7 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
/* We ignore the case where there is no left input channel.
* Something is really wrong in this case anyway. */
- } else if (on_right(b)) {
+ } else if (on_right(b) && !(r->flags & PA_RESAMPLER_NO_FILL_SINK)) {
/* We are not connected and on the right side, let's
* average all right side input channels. */
@@ -976,7 +1040,7 @@ static void setup_remap(const pa_resampler *r, pa_remap_t *m, bool *lfe_remixed)
* channel. Something is really wrong in this case anyway.
* */
- } else if (on_center(b)) {
+ } else if (on_center(b) && !(r->flags & PA_RESAMPLER_NO_FILL_SINK)) {
if (ic_center > 0) {
diff --git a/src/pulsecore/resampler.h b/src/pulsecore/resampler.h
index 4469022..5d3171f 100644
--- a/src/pulsecore/resampler.h
+++ b/src/pulsecore/resampler.h
@@ -68,7 +68,8 @@ typedef enum pa_resample_flags {
PA_RESAMPLER_VARIABLE_RATE = 0x0001U,
PA_RESAMPLER_NO_REMAP = 0x0002U, /* implies NO_REMIX */
PA_RESAMPLER_NO_REMIX = 0x0004U,
- PA_RESAMPLER_NO_LFE = 0x0008U
+ PA_RESAMPLER_NO_LFE = 0x0008U,
+ PA_RESAMPLER_NO_FILL_SINK = 0x0010U,
} pa_resample_flags_t;
struct pa_resampler {
--
2.7.4
More information about the pulseaudio-discuss
mailing list