[FFmpeg-devel] [PATCH 1/2] Define ff_inverse also in libavutil.

[Diego 'Flameeyes' Pettenò]

The FASTDIV macro (defined in libavutil/internal.h, and used by many
libavutil functions) requires access to ff_inverse, but this is
defined in libavcodec, adding a libavcodec dependency on libavutil.

By creating a copy of ff_inverse defined inside libavutil, the library
becomes independent.

With this change, libavutil can be built with -Wl,-z,defs with GNU or
Sun linkers, without undefined symbols on the library.
---

 libavutil/mathematics.c |   36 ++++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c
index ef93ba4..b8b26cd 100644
--- a/libavutil/mathematics.c
+++ b/libavutil/mathematics.c
@@ -37,6 +37,42 @@ const uint8_t ff_sqrt_tab[256]={
 240,240,241,242,242,243,243,244,244,245,245,246,246,247,247,248,248,249,249,250,250,251,251,252,252,253,253,254,254,255,255,255
 };
 
+/* a*inverse[b]>>32 == a/b for all 0<=a<=65536 && 2<=b<=255 */
+const uint32_t ff_inverse[256]={
+         0, 4294967295U,2147483648U,1431655766, 1073741824,  858993460,  715827883,  613566757,
+ 536870912,  477218589,  429496730,  390451573,  357913942,  330382100,  306783379,  286331154,
+ 268435456,  252645136,  238609295,  226050911,  214748365,  204522253,  195225787,  186737709,
+ 178956971,  171798692,  165191050,  159072863,  153391690,  148102321,  143165577,  138547333,
+ 134217728,  130150525,  126322568,  122713352,  119304648,  116080198,  113025456,  110127367,
+ 107374183,  104755300,  102261127,   99882961,   97612894,   95443718,   93368855,   91382283,
+  89478486,   87652394,   85899346,   84215046,   82595525,   81037119,   79536432,   78090315,
+  76695845,   75350304,   74051161,   72796056,   71582789,   70409300,   69273667,   68174085,
+  67108864,   66076420,   65075263,   64103990,   63161284,   62245903,   61356676,   60492498,
+  59652324,   58835169,   58040099,   57266231,   56512728,   55778797,   55063684,   54366675,
+  53687092,   53024288,   52377650,   51746594,   51130564,   50529028,   49941481,   49367441,
+  48806447,   48258060,   47721859,   47197443,   46684428,   46182445,   45691142,   45210183,
+  44739243,   44278014,   43826197,   43383509,   42949673,   42524429,   42107523,   41698712,
+  41297763,   40904451,   40518560,   40139882,   39768216,   39403370,   39045158,   38693400,
+  38347923,   38008561,   37675152,   37347542,   37025581,   36709123,   36398028,   36092163,
+  35791395,   35495598,   35204650,   34918434,   34636834,   34359739,   34087043,   33818641,
+  33554432,   33294321,   33038210,   32786010,   32537632,   32292988,   32051995,   31814573,
+  31580642,   31350127,   31122952,   30899046,   30678338,   30460761,   30246249,   30034737,
+  29826162,   29620465,   29417585,   29217465,   29020050,   28825284,   28633116,   28443493,
+  28256364,   28071682,   27889399,   27709467,   27531842,   27356480,   27183338,   27012373,
+  26843546,   26676816,   26512144,   26349493,   26188825,   26030105,   25873297,   25718368,
+  25565282,   25414008,   25264514,   25116768,   24970741,   24826401,   24683721,   24542671,
+  24403224,   24265352,   24129030,   23994231,   23860930,   23729102,   23598722,   23469767,
+  23342214,   23216040,   23091223,   22967740,   22845571,   22724695,   22605092,   22486740,
+  22369622,   22253717,   22139007,   22025474,   21913099,   21801865,   21691755,   21582751,
+  21474837,   21367997,   21262215,   21157475,   21053762,   20951060,   20849356,   20748635,
+  20648882,   20550083,   20452226,   20355296,   20259280,   20164166,   20069941,   19976593,
+  19884108,   19792477,   19701685,   19611723,   19522579,   19434242,   19346700,   19259944,
+  19173962,   19088744,   19004281,   18920561,   18837576,   18755316,   18673771,   18592933,
+  18512791,   18433337,   18354562,   18276457,   18199014,   18122225,   18046082,   17970575,
+  17895698,   17821442,   17747799,   17674763,   17602325,   17530479,   17459217,   17388532,
+  17318417,   17248865,   17179870,   17111424,   17043522,   16976156,   16909321,   16843010,
+};
+
 const uint8_t ff_log2_tab[256]={
         0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
         5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,