[FFmpeg-devel] [PATCH 2/3] bink: get rid of double precission float use

Michael Niedermayer michaelni at gmx.at
Mon Feb 6 19:31:04 CET 2012


Add a small table of integers and out commented code to generate it with
the double precision code.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavcodec/bink.c |   36 ++++++++++++++++++++++++------------
 1 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/libavcodec/bink.c b/libavcodec/bink.c
index ff8bc8a..c77c139 100644
--- a/libavcodec/bink.c
+++ b/libavcodec/bink.c
@@ -1222,40 +1222,52 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPac
 static av_cold void binkb_calc_quant(void)
 {
     uint8_t inv_bink_scan[64];
-    double s[64];
+    static const int s[64]={
+        1073741824,1489322693,1402911301,1262586814,1073741824, 843633538, 581104888, 296244703,
+        1489322693,2065749918,1945893874,1751258219,1489322693,1170153332, 806015634, 410903207,
+        1402911301,1945893874,1832991949,1649649171,1402911301,1102260336, 759250125, 387062357,
+        1262586814,1751258219,1649649171,1484645031,1262586814, 992008094, 683307060, 348346918,
+        1073741824,1489322693,1402911301,1262586814,1073741824, 843633538, 581104888, 296244703,
+         843633538,1170153332,1102260336, 992008094, 843633538, 662838617, 456571181, 232757969,
+         581104888, 806015634, 759250125, 683307060, 581104888, 456571181, 314491699, 160326478,
+         296244703, 410903207, 387062357, 348346918, 296244703, 232757969, 160326478,  81733730,
+    };
     int i, j;
-
+#define C (1LL<<30)
+#if 0
     for (j = 0; j < 8; j++) {
         for (i = 0; i < 8; i++) {
             if (j && j != 4)
                if (i && i != 4)
-                   s[j*8 + i] = cos(j * M_PI/16.0) * cos(i * M_PI/16.0) * 2.0;
+                   s[j*8 + i] = llrint(cos(j * M_PI/16.0) * cos(i * M_PI/16.0) * 2.0 * C);
                else
-                   s[j*8 + i] = cos(j * M_PI/16.0) * sqrt(2.0);
+                   s[j*8 + i] = llrint(cos(j * M_PI/16.0) * sqrt(2.0)* C);
             else
                if (i && i != 4)
-                   s[j*8 + i] = cos(i * M_PI/16.0) * sqrt(2.0);
+                   s[j*8 + i] = llrint(cos(i * M_PI/16.0) * sqrt(2.0)* C);
                else
-                   s[j*8 + i] = 1.0;
+                   s[j*8 + i] = llrint(1.0* C);
+            av_log(0,0, "%10d,", s[j*8 + i]);
         }
+        av_log(0,0, "\n");
     }
-
+#endif
     for (i = 0; i < 64; i++)
         inv_bink_scan[bink_scan[i]] = i;
 
     for (j = 0; j < 16; j++) {
         for (i = 0; i < 64; i++) {
             int k = inv_bink_scan[i];
-            if (s[i] == 1.0) {
+            if (s[i] == C) {
                 binkb_intra_quant[j][k] = (1L << 12) * binkb_intra_seed[i] *
                                           binkb_num[j]/binkb_den[j];
                 binkb_inter_quant[j][k] = (1L << 12) * binkb_inter_seed[i] *
                                           binkb_num[j]/binkb_den[j];
             } else {
-                binkb_intra_quant[j][k] = (1L << 12) * binkb_intra_seed[i] * s[i] *
-                                          binkb_num[j]/(double)binkb_den[j];
-                binkb_inter_quant[j][k] = (1L << 12) * binkb_inter_seed[i] * s[i] *
-                                          binkb_num[j]/(double)binkb_den[j];
+                binkb_intra_quant[j][k] = binkb_intra_seed[i] * (int64_t)s[i] *
+                                          binkb_num[j]/(binkb_den[j] * (C>>12));
+                binkb_inter_quant[j][k] = binkb_inter_seed[i] * (int64_t)s[i] *
+                                          binkb_num[j]/(binkb_den[j] * (C>>12));
             }
         }
     }
-- 
1.7.5.4



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