ffmpeg/libavcodec/alpha/mpegvideo_alpha.c

103 lines
3.2 KiB
C

/*
* Alpha optimized DSP utils
* Copyright (c) 2002 Falk Hueffner <falk@debian.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "asm.h"
#include "../dsputil.h"
#include "../mpegvideo.h"
extern void simple_idct_put_axp(uint8_t *dest, int line_size, DCTELEM *block);
extern void simple_idct_add_axp(uint8_t *dest, int line_size, DCTELEM *block);
static void dct_unquantize_h263_axp(MpegEncContext *s, DCTELEM *block,
int n, int qscale)
{
int i, n_coeffs;
uint64_t qmul, qadd;
uint64_t correction;
DCTELEM *orig_block = block;
DCTELEM block0;
qadd = WORD_VEC((qscale - 1) | 1);
qmul = qscale << 1;
/* This mask kills spill from negative subwords to the next subword. */
correction = WORD_VEC((qmul - 1) + 1); /* multiplication / addition */
if (s->mb_intra) {
if (!s->h263_aic) {
if (n < 4)
block0 = block[0] * s->y_dc_scale;
else
block0 = block[0] * s->c_dc_scale;
} else {
qadd = 0;
}
n_coeffs = 63; // does not always use zigzag table
} else {
n_coeffs = s->intra_scantable.raster_end[s->block_last_index[n]];
}
for(i = 0; i <= n_coeffs; block += 4, i += 4) {
uint64_t levels, negmask, zeros, add;
levels = ldq(block);
if (levels == 0)
continue;
#ifdef __alpha_max__
/* I don't think the speed difference justifies runtime
detection. */
ASM_ACCEPT_MVI;
negmask = maxsw4(levels, -1); /* negative -> ffff (-1) */
negmask = minsw4(negmask, 0); /* positive -> 0000 (0) */
#else
negmask = cmpbge(WORD_VEC(0x7fff), levels);
negmask &= (negmask >> 1) | (1 << 7);
negmask = zap(-1, negmask);
#endif
zeros = cmpbge(0, levels);
zeros &= zeros >> 1;
/* zeros |= zeros << 1 is not needed since qadd <= 255, so
zapping the lower byte suffices. */
levels *= qmul;
levels -= correction & (negmask << 16);
/* Negate qadd for negative levels. */
add = qadd ^ negmask;
add += WORD_VEC(0x0001) & negmask;
/* Set qadd to 0 for levels == 0. */
add = zap(add, zeros);
levels += add;
stq(levels, block);
}
if (s->mb_intra && !s->h263_aic)
orig_block[0] = block0;
}
void MPV_common_init_axp(MpegEncContext *s)
{
s->dct_unquantize_h263 = dct_unquantize_h263_axp;
s->idct_put = simple_idct_put_axp;
s->idct_add = simple_idct_add_axp;
}