libavcodec: Implementation of AC3 fixedpoint decoder

Signed-off-by: Nedeljko Babic <nbabic@mips.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 26 insertions, 0 deletions

diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c
index 0d5ea39d08..b746817c9d 100644
--- a/libavcodec/ac3dsp.c
+++ b/libavcodec/ac3dsp.c
@@ -239,6 +239,31 @@ static void ac3_downmix_c(float **samples, float (*matrix)[2],
     }
 }
 
+static void ac3_downmix_c_fixed(int32_t **samples, int16_t (*matrix)[2],
+                                int out_ch, int in_ch, int len)
+{
+    int i, j;
+    int64_t v0, v1;
+    if (out_ch == 2) {
+        for (i = 0; i < len; i++) {
+            v0 = v1 = 0;
+            for (j = 0; j < in_ch; j++) {
+                v0 += (int64_t)samples[j][i] * matrix[j][0];
+                v1 += (int64_t)samples[j][i] * matrix[j][1];
+            }
+            samples[0][i] = (v0+2048)>>12;
+            samples[1][i] = (v1+2048)>>12;
+        }
+    } else if (out_ch == 1) {
+        for (i = 0; i < len; i++) {
+            v0 = 0;
+            for (j = 0; j < in_ch; j++)
+                v0 += (int64_t)samples[j][i] * matrix[j][0];
+            samples[0][i] = (v0+2048)>>12;
+        }
+    }
+}
+
 static void apply_window_int16_c(int16_t *output, const int16_t *input,
                                  const int16_t *window, unsigned int len)
 {
@@ -266,6 +291,7 @@ av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
     c->sum_square_butterfly_int32 = ac3_sum_square_butterfly_int32_c;
     c->sum_square_butterfly_float = ac3_sum_square_butterfly_float_c;
     c->downmix = ac3_downmix_c;
+    c->downmix_fixed = ac3_downmix_c_fixed;
     c->apply_window_int16 = apply_window_int16_c;
 
     if (ARCH_ARM)