flacdec: move lpc filter to flacdsp

Signed-off-by: Mans Rullgard <mans@mansr.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/libavcodec/flacdsp.c b/libavcodec/flacdsp.c
index b7e074644e..fcee8e44c7 100644
--- a/libavcodec/flacdsp.c
+++ b/libavcodec/flacdsp.c
@@ -29,6 +29,49 @@
 #define SAMPLE_SIZE 32
 #include "flacdsp_template.c"
 
+static void flac_lpc_16_c(int32_t *decoded, const int coeffs[32],
+                          int pred_order, int qlevel, int len)
+{
+    int i, j;
+
+    for (i = pred_order; i < len - 1; i += 2) {
+        int c;
+        int d = decoded[i-pred_order];
+        int s0 = 0, s1 = 0;
+        for (j = pred_order-1; j > 0; j--) {
+            c = coeffs[j];
+            s0 += c*d;
+            d = decoded[i-j];
+            s1 += c*d;
+        }
+        c = coeffs[0];
+        s0 += c*d;
+        d = decoded[i] += s0 >> qlevel;
+        s1 += c*d;
+        decoded[i+1] += s1 >> qlevel;
+    }
+    if (i < len) {
+        int sum = 0;
+        for (j = 0; j < pred_order; j++)
+            sum += coeffs[j] * decoded[i-j-1];
+        decoded[i] += sum >> qlevel;
+    }
+}
+
+static void flac_lpc_32_c(int32_t *decoded, const int coeffs[32],
+                          int pred_order, int qlevel, int len)
+{
+    int i, j;
+
+    for (i = pred_order; i < len; i++) {
+        int64_t sum = 0;
+        for (j = 0; j < pred_order; j++)
+            sum += (int64_t)coeffs[j] * decoded[i-j-1];
+        decoded[i] += sum >> qlevel;
+    }
+
+}
+
 av_cold void ff_flacdsp_init(FLACDSPContext *c, enum AVSampleFormat fmt)
 {
     switch (fmt) {
@@ -37,6 +80,7 @@ av_cold void ff_flacdsp_init(FLACDSPContext *c, enum AVSampleFormat fmt)
         c->decorrelate[1] = flac_decorrelate_ls_c_32;
         c->decorrelate[2] = flac_decorrelate_rs_c_32;
         c->decorrelate[3] = flac_decorrelate_ms_c_32;
+        c->lpc            = flac_lpc_32_c;
         break;
 
     case AV_SAMPLE_FMT_S16:
@@ -44,6 +88,7 @@ av_cold void ff_flacdsp_init(FLACDSPContext *c, enum AVSampleFormat fmt)
         c->decorrelate[1] = flac_decorrelate_ls_c_16;
         c->decorrelate[2] = flac_decorrelate_rs_c_16;
         c->decorrelate[3] = flac_decorrelate_ms_c_16;
+        c->lpc            = flac_lpc_16_c;
         break;
     }
 }