pcm dmix plugin: fix generic direct remixing

In the case of the sum buffer being uninitialized, the source sample
must be negated not only when writing to the sum but also when writing
to the destination.

diff --git a/src/pcm/pcm_dmix_generic.c b/src/pcm/pcm_dmix_generic.c
index 29ea91a7beea6b0543b87f88d20115b284d6d603..a1086c9513b88f43927253ef7f206e0b77b00180 100644 (file)
--- a/src/pcm/pcm_dmix_generic.c
+++ b/src/pcm/pcm_dmix_generic.c
@@ -173,7 +173,7 @@ static void generic_remix_areas_16_native(unsigned int size,
                sample = *src;
                if (! *dst) {
                        *sum = -sample;
-                       *dst = *src;
+                       *dst = -sample;
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7fff)
@@ -238,7 +238,7 @@ static void generic_remix_areas_32_native(unsigned int size,
                sample = *src >> 8;
                if (! *dst) {
                        *sum = -sample;
-                       *dst = *src;
+                       *dst = -*src;
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7fffff)
@@ -303,7 +303,7 @@ static void generic_remix_areas_16_swap(unsigned int size,
                sample = (signed short) bswap_16(*src);
                if (! *dst) {
                        *sum = -sample;
-                       *dst = *src;
+                       *dst = (signed short) bswap_16((signed short) -sample);
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7fff)
@@ -368,7 +368,7 @@ static void generic_remix_areas_32_swap(unsigned int size,
                sample = bswap_32(*src) >> 8;
                if (! *dst) {
                        *sum = -sample;
-                       *dst = *src;
+                       *dst = bswap_32(-sample);
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7fffff)
@@ -434,7 +434,8 @@ static void generic_remix_areas_24(unsigned int size,
        for (;;) {
                sample = src[0] | (src[1] << 8) | (((signed char *)src)[2] << 16);
                if (!(dst[0] | dst[1] | dst[2])) {
-                       *sum = -sample;
+                       sample = -sample;
+                       *sum = sample;
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7fffff)
@@ -493,7 +494,8 @@ static void generic_remix_areas_u8(unsigned int size,
        for (;;) {
                register int sample = *src - 0x80;
                if (*dst == 0x80) {
-                       *sum = -sample;
+                       sample = -sample;
+                       *sum = sample;
                } else {
                        *sum = sample = *sum - sample;
                        if (sample > 0x7f)