halfpel MC doxy

Originally committed as revision 1684 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/dsputil.h

@@ -116,7 +116,13 @@ typedef struct DSPContext {
     void (*diff_pixels)(DCTELEM *block/*align 16*/, const uint8_t *s1/*align 8*/, const uint8_t *s2/*align 8*/, int stride);
     void (*put_pixels_clamped)(const DCTELEM *block/*align 16*/, uint8_t *pixels/*align 8*/, int line_size);
     void (*add_pixels_clamped)(const DCTELEM *block/*align 16*/, uint8_t *pixels/*align 8*/, int line_size);
+    /**
+     * translational global motion compensation.
+     */
     void (*gmc1)(uint8_t *dst/*align 8*/, uint8_t *src/*align 1*/, int srcStride, int h, int x16, int y16, int rounder);
+    /**
+     * global motion compensation.
+     */
     void (*gmc )(uint8_t *dst/*align 8*/, uint8_t *src/*align 1*/, int stride, int h, int ox, int oy,
 		    int dxx, int dxy, int dyx, int dyy, int shift, int r, int width, int height);
     void (*clear_blocks)(DCTELEM *blocks/*align 16*/);
@@ -137,9 +143,44 @@ typedef struct DSPContext {
     me_cmp_func mb_cmp[11];
 
     /* maybe create an array for 16/8 functions */
+    /**
+     * Halfpel motion compensation with rounding (a+b+1)>>1.
+     * *pixels_tab[ 0->16x16 1->8x8 ][ xhalfpel + 2*yhalfpel ]
+     * @param block destination where the result is stored
+     * @param pixels source
+     * @param line_size number of bytes in a horizontal line of block
+     * @param h height
+     */
     op_pixels_func put_pixels_tab[2][4];
+
+    /**
+     * Halfpel motion compensation with rounding (a+b+1)>>1.
+     * *pixels_tab[ 0->16x16 1->8x8 ][ xhalfpel + 2*yhalfpel ]
+     * @param block destination into which the result is averaged (a+b+1)>>1
+     * @param pixels source
+     * @param line_size number of bytes in a horizontal line of block
+     * @param h height
+     */
     op_pixels_func avg_pixels_tab[2][4];
+
+    /**
+     * Halfpel motion compensation with no rounding (a+b)>>1.
+     * *pixels_tab[ 0->16x16 1->8x8 ][ xhalfpel + 2*yhalfpel ]
+     * @param block destination where the result is stored
+     * @param pixels source
+     * @param line_size number of bytes in a horizontal line of block
+     * @param h height
+     */
     op_pixels_func put_no_rnd_pixels_tab[2][4];
+
+    /**
+     * Halfpel motion compensation with no rounding (a+b)>>1.
+     * *pixels_tab[ 0->16x16 1->8x8 ][ xhalfpel + 2*yhalfpel ]
+     * @param block destination into which the result is averaged (a+b)>>1
+     * @param pixels source
+     * @param line_size number of bytes in a horizontal line of block
+     * @param h height
+     */
     op_pixels_func avg_no_rnd_pixels_tab[2][4];
     qpel_mc_func put_qpel_pixels_tab[2][16];
     qpel_mc_func avg_qpel_pixels_tab[2][16];