Merge rotation into lookup table.

Originally committed as revision 25774 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/wc3movie.c

@@ -83,40 +83,41 @@ typedef struct Wc3DemuxContext {
  * rounding issues, the maximum difference between
  * the table values and the calculated doubles is
  * about 0.497527
+ * The left-rotation of the input by 2 is also included in this table.
  */
 static const unsigned char wc3_pal_lookup[] = {
-  0x00, 0x03, 0x05, 0x07, 0x09, 0x0B, 0x0D, 0x0E,
-  0x10, 0x12, 0x13, 0x15, 0x16, 0x18, 0x19, 0x1A,
-  0x1C, 0x1D, 0x1F, 0x20, 0x21, 0x23, 0x24, 0x25,
-  0x27, 0x28, 0x29, 0x2A, 0x2C, 0x2D, 0x2E, 0x2F,
-  0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x38, 0x39,
-  0x3A, 0x3B, 0x3C, 0x3D, 0x3F, 0x40, 0x41, 0x42,
-  0x43, 0x44, 0x45, 0x46, 0x48, 0x49, 0x4A, 0x4B,
-  0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53,
-  0x54, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C,
-  0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64,
-  0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C,
-  0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74,
-  0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
-  0x7D, 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83,
-  0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
-  0x8C, 0x8D, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
-  0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x99,
-  0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1,
-  0xA2, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
-  0xA9, 0xAA, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
-  0xB0, 0xB1, 0xB2, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6,
-  0xB7, 0xB8, 0xB9, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD,
-  0xBE, 0xBF, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4,
-  0xC5, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB,
-  0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD0, 0xD1,
-  0xD2, 0xD3, 0xD4, 0xD5, 0xD5, 0xD6, 0xD7, 0xD8,
-  0xD9, 0xDA, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
-  0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE4, 0xE5,
-  0xE6, 0xE7, 0xE8, 0xE9, 0xE9, 0xEA, 0xEB, 0xEC,
-  0xED, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF1, 0xF2,
-  0xF3, 0xF4, 0xF5, 0xF6, 0xF6, 0xF7, 0xF8, 0xF9,
-  0xFA, 0xFA, 0xFB, 0xFC, 0xFD, 0xFD, 0xFD, 0xFD
+    0x00, 0x09, 0x10, 0x16, 0x1C, 0x21, 0x27, 0x2C,
+    0x31, 0x35, 0x3A, 0x3F, 0x43, 0x48, 0x4C, 0x50,
+    0x54, 0x59, 0x5D, 0x61, 0x65, 0x69, 0x6D, 0x71,
+    0x75, 0x79, 0x7D, 0x80, 0x84, 0x88, 0x8C, 0x8F,
+    0x93, 0x97, 0x9A, 0x9E, 0xA2, 0xA5, 0xA9, 0xAC,
+    0xB0, 0xB3, 0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8,
+    0xCB, 0xCF, 0xD2, 0xD5, 0xD9, 0xDC, 0xDF, 0xE3,
+    0xE6, 0xE9, 0xED, 0xF0, 0xF3, 0xF6, 0xFA, 0xFD,
+    0x03, 0x0B, 0x12, 0x18, 0x1D, 0x23, 0x28, 0x2D,
+    0x32, 0x36, 0x3B, 0x40, 0x44, 0x49, 0x4D, 0x51,
+    0x56, 0x5A, 0x5E, 0x62, 0x66, 0x6A, 0x6E, 0x72,
+    0x76, 0x7A, 0x7D, 0x81, 0x85, 0x89, 0x8D, 0x90,
+    0x94, 0x98, 0x9B, 0x9F, 0xA2, 0xA6, 0xAA, 0xAD,
+    0xB1, 0xB4, 0xB8, 0xBB, 0xBF, 0xC2, 0xC5, 0xC9,
+    0xCC, 0xD0, 0xD3, 0xD6, 0xDA, 0xDD, 0xE0, 0xE4,
+    0xE7, 0xEA, 0xED, 0xF1, 0xF4, 0xF7, 0xFA, 0xFD,
+    0x05, 0x0D, 0x13, 0x19, 0x1F, 0x24, 0x29, 0x2E,
+    0x33, 0x38, 0x3C, 0x41, 0x45, 0x4A, 0x4E, 0x52,
+    0x57, 0x5B, 0x5F, 0x63, 0x67, 0x6B, 0x6F, 0x73,
+    0x77, 0x7B, 0x7E, 0x82, 0x86, 0x8A, 0x8D, 0x91,
+    0x95, 0x99, 0x9C, 0xA0, 0xA3, 0xA7, 0xAA, 0xAE,
+    0xB2, 0xB5, 0xB9, 0xBC, 0xBF, 0xC3, 0xC6, 0xCA,
+    0xCD, 0xD0, 0xD4, 0xD7, 0xDA, 0xDE, 0xE1, 0xE4,
+    0xE8, 0xEB, 0xEE, 0xF1, 0xF5, 0xF8, 0xFB, 0xFD,
+    0x07, 0x0E, 0x15, 0x1A, 0x20, 0x25, 0x2A, 0x2F,
+    0x34, 0x39, 0x3D, 0x42, 0x46, 0x4B, 0x4F, 0x53,
+    0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C, 0x70, 0x74,
+    0x78, 0x7C, 0x7F, 0x83, 0x87, 0x8B, 0x8E, 0x92,
+    0x96, 0x99, 0x9D, 0xA1, 0xA4, 0xA8, 0xAB, 0xAF,
+    0xB2, 0xB6, 0xB9, 0xBD, 0xC0, 0xC4, 0xC7, 0xCB,
+    0xCE, 0xD1, 0xD5, 0xD8, 0xDB, 0xDF, 0xE2, 0xE5,
+    0xE9, 0xEC, 0xEF, 0xF2, 0xF6, 0xF9, 0xFC, 0xFD
 };
 
 
@@ -144,7 +145,6 @@ static int wc3_read_header(AVFormatContext *s,
     int current_palette = 0;
     char *buffer;
     int i;
-    unsigned char rotate;
 
     /* default context members */
     wc3->width = WC3_DEFAULT_WIDTH;
@@ -212,11 +212,7 @@ static int wc3_read_header(AVFormatContext *s,
             /* transform the current palette in place */
             for (i = current_palette * PALETTE_SIZE;
                  i < (current_palette + 1) * PALETTE_SIZE; i++) {
-                /* rotate each palette component left by 2 and use the result
-                 * as an index into the color component table */
-                rotate = ((wc3->palettes[i] << 2) & 0xFF) |
-                         ((wc3->palettes[i] >> 6) & 0xFF);
-                wc3->palettes[i] = wc3_pal_lookup[rotate];
+                wc3->palettes[i] = wc3_pal_lookup[wc3->palettes[i]];
             }
             current_palette++;
             break;