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minor optimization of h263_encode_motion()
Originally committed as revision 976 to svn://svn.ffmpeg.org/ffmpeg/trunk
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202ef8b819
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@ -1079,7 +1079,7 @@ INT16 *h263_pred_motion(MpegEncContext * s, int block,
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static void h263_encode_motion(MpegEncContext * s, int val, int f_code)
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{
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int range, l, m, bit_size, sign, code, bits;
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int range, l, bit_size, sign, code, bits;
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if (val == 0) {
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/* zero vector */
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@ -1090,12 +1090,20 @@ static void h263_encode_motion(MpegEncContext * s, int val, int f_code)
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range = 1 << bit_size;
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/* modulo encoding */
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l = range * 32;
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m = 2 * l;
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#if 1
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val+= l;
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val&= 2*l-1;
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val-= l;
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sign = val>>31;
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val= (val^sign)-sign;
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sign&=1;
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#else
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if (val < -l) {
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val += m;
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val += 2*l;
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} else if (val >= l) {
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val -= m;
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val -= 2*l;
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}
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assert(val>=-l && val<l);
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if (val >= 0) {
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@ -1104,6 +1112,7 @@ static void h263_encode_motion(MpegEncContext * s, int val, int f_code)
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val = -val;
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sign = 1;
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}
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#endif
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val--;
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code = (val >> bit_size) + 1;
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bits = val & (range - 1);
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