channelmix: improve undefined channel layout

When we have no channel layout, just copy input to output
channel.
Optimize this case in the mixer implementation.

3 files changed, 35 insertions, 10 deletions

diff --git a/spa/plugins/audioconvert/channelmix-ops-c.c b/spa/plugins/audioconvert/channelmix-ops-c.c
index 710ed384..f839cbdd 100644
--- a/spa/plugins/audioconvert/channelmix-ops-c.c
+++ b/spa/plugins/audioconvert/channelmix-ops-c.c
@@ -58,12 +58,25 @@ channelmix_f32_n_m_c(struct channelmix *mix, uint32_t n_dst, void * SPA_RESTRICT
 	float **d = (float **) dst;
 	const float **s = (const float **) src;
 
-	for (n = 0; n < n_samples; n++) {
-		for (i = 0; i < n_dst; i++) {
-			float sum = 0.0f;
-			for (j = 0; j < n_src; j++)
-				sum += s[j][n] * mix->matrix[i][j];
-			d[i][n] = sum;
+	if (SPA_FLAG_IS_SET(mix->flags, CHANNELMIX_FLAG_ZERO)) {
+		for (i = 0; i < n_dst; i++)
+			memset(d[i], 0, n_samples * sizeof(float));
+	}
+	else if (SPA_FLAG_IS_SET(mix->flags, CHANNELMIX_FLAG_COPY)) {
+		uint32_t copy = SPA_MIN(n_dst, n_src);
+		for (i = 0; i < copy; i++)
+			spa_memcpy(d[i], s[i], n_samples * sizeof(float));
+		for (; i < n_dst; i++)
+			memset(d[i], 0, n_samples * sizeof(float));
+	}
+	else {
+		for (n = 0; n < n_samples; n++) {
+			for (i = 0; i < n_dst; i++) {
+				float sum = 0.0f;
+				for (j = 0; j < n_src; j++)
+					sum += s[j][n] * mix->matrix[i][j];
+				d[i][n] = sum;
+			}
 		}
 	}
 }
diff --git a/spa/plugins/audioconvert/channelmix-ops.c b/spa/plugins/audioconvert/channelmix-ops.c
index 24c03817..384f08ed 100644
--- a/spa/plugins/audioconvert/channelmix-ops.c
+++ b/spa/plugins/audioconvert/channelmix-ops.c
@@ -175,9 +175,16 @@ static int make_matrix(struct channelmix *mix)
 	if ((dst_mask & _MASK(MONO)) == _MASK(MONO))
 		dst_mask = _MASK(FC);
 
-	for (i = 0; i < NUM_CHAN; i++) {
-		if (src_mask & dst_mask & (1ULL << (i + 2)))
+	if (src_mask == 0 || dst_mask == 0) {
+		src_mask = dst_mask = ~0LU;
+		for (i = 0; i < NUM_CHAN; i++)
 			matrix[i][i]= 1.0f;
+		goto done;
+	} else {
+		for (i = 0; i < NUM_CHAN; i++) {
+			if ((src_mask & dst_mask & (1ULL << (i + 2))))
+				matrix[i][i]= 1.0f;
+		}
 	}
 
 	unassigned = src_mask & ~dst_mask;
@@ -329,6 +336,7 @@ static int make_matrix(struct channelmix *mix)
 			spa_log_warn(mix->log, "can't assign LFE");
 		}
 	}
+done:
 	for (ic = 0, i = 0; i < NUM_CHAN; i++) {
 		float sum = 0.0f;
 		if ((dst_mask & (1UL << (i + 2))) == 0)
@@ -377,7 +385,7 @@ static void impl_channelmix_set_volume(struct channelmix *mix, float volume, boo
 
 	SPA_FLAG_SET(mix->flags, CHANNELMIX_FLAG_ZERO);
 	SPA_FLAG_SET(mix->flags, CHANNELMIX_FLAG_EQUAL);
-	SPA_FLAG_UPDATE(mix->flags, CHANNELMIX_FLAG_IDENTITY, dst_chan == src_chan);
+	SPA_FLAG_SET(mix->flags, CHANNELMIX_FLAG_COPY);
 
 	t = 0.0;
 	for (i = 0; i < dst_chan; i++) {
@@ -392,9 +400,12 @@ static void impl_channelmix_set_volume(struct channelmix *mix, float volume, boo
 				SPA_FLAG_CLEAR(mix->flags, CHANNELMIX_FLAG_ZERO);
 			if ((i == j && v != 1.0f) ||
 			    (i != j && v != 0.0f))
-				SPA_FLAG_CLEAR(mix->flags, CHANNELMIX_FLAG_IDENTITY);
+				SPA_FLAG_CLEAR(mix->flags, CHANNELMIX_FLAG_COPY);
 		}
 	}
+	SPA_FLAG_UPDATE(mix->flags, CHANNELMIX_FLAG_IDENTITY,
+			dst_chan == src_chan && SPA_FLAG_IS_SET(mix->flags, CHANNELMIX_FLAG_COPY));
+
 	spa_log_debug(mix->log, "flags:%08x", mix->flags);
 }
 
diff --git a/spa/plugins/audioconvert/channelmix-ops.h b/spa/plugins/audioconvert/channelmix-ops.h
index 1f967450..4aac0554 100644
--- a/spa/plugins/audioconvert/channelmix-ops.h
+++ b/spa/plugins/audioconvert/channelmix-ops.h
@@ -54,6 +54,7 @@ struct channelmix {
 #define CHANNELMIX_FLAG_ZERO		(1<<0)		/**< all zero components */
 #define CHANNELMIX_FLAG_IDENTITY	(1<<1)		/**< identity matrix */
 #define CHANNELMIX_FLAG_EQUAL		(1<<2)		/**< all values are equal */
+#define CHANNELMIX_FLAG_COPY		(1<<3)		/**< 1 on diagonal, can be nxm */
 	uint32_t flags;
 	float matrix_orig[SPA_AUDIO_MAX_CHANNELS][SPA_AUDIO_MAX_CHANNELS];
 	float matrix[SPA_AUDIO_MAX_CHANNELS][SPA_AUDIO_MAX_CHANNELS];