h264pred: fix aliasing violations.

[ffmpeg] / libavcodec / ac3dsp.c

diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c
index 42b44f7db8cbec93d062f8d534af46ab08316bf5..e3ca37ebdd49da3e8e37b91163e2bc5cc3999596 100644 (file)
--- a/libavcodec/ac3dsp.c
+++ b/libavcodec/ac3dsp.c
@@ -19,7 +19,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/avassert.h"
 #include "avcodec.h"
+#include "ac3.h"
 #include "ac3dsp.h"
 
 static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
@@ -101,6 +103,76 @@ static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
     } while (len > 0);
 }
 
+static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
+                                     int start, int end,
+                                     int snr_offset, int floor,
+                                     const uint8_t *bap_tab, uint8_t *bap)
+{
+    int bin, band;
+
+    /* special case, if snr offset is -960, set all bap's to zero */
+    if (snr_offset == -960) {
+        memset(bap, 0, AC3_MAX_COEFS);
+        return;
+    }
+
+    bin  = start;
+    band = ff_ac3_bin_to_band_tab[start];
+    do {
+        int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
+        int band_end = FFMIN(ff_ac3_band_start_tab[band+1], end);
+        for (; bin < band_end; bin++) {
+            int address = av_clip((psd[bin] - m) >> 5, 0, 63);
+            bap[bin] = bap_tab[address];
+        }
+    } while (end > ff_ac3_band_start_tab[band++]);
+}
+
+static int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap,
+                                       int nb_coefs)
+{
+    int bits, b, i;
+
+    bits = 0;
+    for (i = 0; i < nb_coefs; i++) {
+        b = bap[i];
+        if (b <= 4) {
+            // bap=1 to bap=4 will be counted in compute_mantissa_size_final
+            mant_cnt[b]++;
+        } else if (b <= 13) {
+            // bap=5 to bap=13 use (bap-1) bits
+            bits += b - 1;
+        } else {
+            // bap=14 uses 14 bits and bap=15 uses 16 bits
+            bits += (b == 14) ? 14 : 16;
+        }
+    }
+    return bits;
+}
+
+static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
+{
+    int i;
+
+    for (i = 0; i < nb_coefs; i++) {
+        int e;
+        int v = abs(coef[i]);
+        if (v == 0)
+            e = 24;
+        else {
+            e = 23 - av_log2(v);
+            if (e >= 24) {
+                e = 24;
+                coef[i] = 0;
+            } else if (e < 0) {
+                e = 0;
+                coef[i] = av_clip(coef[i], -16777215, 16777215);
+            }
+        }
+        exp[i] = e;
+    }
+}
+
 av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
 {
     c->ac3_exponent_min = ac3_exponent_min_c;
@@ -108,6 +180,9 @@ av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
     c->ac3_lshift_int16 = ac3_lshift_int16_c;
     c->ac3_rshift_int32 = ac3_rshift_int32_c;
     c->float_to_fixed24 = float_to_fixed24_c;
+    c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
+    c->compute_mantissa_size = ac3_compute_mantissa_size_c;
+    c->extract_exponents = ac3_extract_exponents_c;
 
     if (ARCH_ARM)
         ff_ac3dsp_init_arm(c, bit_exact);