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FFmpeg/libavcodec/huffyuvdsp.c
Andreas Rheinhardt 566280c3f4 avcodec/huffyuv: Split HYuvContext into decoder and encoder context
While the share of elements used by both is quite big, the amount
of code shared between the decoders and encoders is negligible.
Therefore one can easily split the context if one wants to.
The reasons for doing so are that the non-shared elements
are non-negligible: The stats array which is only used by
the encoder takes 524288B of 868904B (on x64); similarly,
pix_bgr_map which is only used by the decoder takes 16KiB.
Furthermore, using a shared context also entails inclusions
of unneeded headers like put_bits.h for the decoder and get_bits.h
for the encoder (and all of these and much more for huffyuv.c).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-10-09 09:15:40 +02:00

94 lines
2.7 KiB
C

/*
* This file is part of FFmpeg.
*
* FFmpeg 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 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdint.h>
#include "config.h"
#include "libavutil/attributes.h"
#include "mathops.h"
#include "huffyuv.h"
#include "huffyuvdsp.h"
// 0x00010001 or 0x0001000100010001 or whatever, depending on the cpu's native arithmetic size
#define pw_1 (ULONG_MAX / UINT16_MAX)
static void add_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, int w){
long i;
unsigned long pw_lsb = (mask >> 1) * pw_1;
unsigned long pw_msb = pw_lsb + pw_1;
for (i = 0; i <= w - (int)sizeof(long)/2; i += sizeof(long)/2) {
long a = *(long*)(src+i);
long b = *(long*)(dst+i);
*(long*)(dst+i) = ((a&pw_lsb) + (b&pw_lsb)) ^ ((a^b)&pw_msb);
}
for(; i<w; i++)
dst[i] = (dst[i] + src[i]) & mask;
}
static void add_hfyu_median_pred_int16_c(uint16_t *dst, const uint16_t *src, const uint16_t *diff, unsigned mask, int w, int *left, int *left_top){
int i;
uint16_t l, lt;
l = *left;
lt = *left_top;
for(i=0; i<w; i++){
l = (mid_pred(l, src[i], (l + src[i] - lt) & mask) + diff[i]) & mask;
lt = src[i];
dst[i] = l;
}
*left = l;
*left_top = lt;
}
static void add_hfyu_left_pred_bgr32_c(uint8_t *dst, const uint8_t *src,
intptr_t w, uint8_t *left)
{
int i;
uint8_t r = left[R], g = left[G], b = left[B], a = left[A];
for (i = 0; i < w; i++) {
b += src[4 * i + B];
g += src[4 * i + G];
r += src[4 * i + R];
a += src[4 * i + A];
dst[4 * i + B] = b;
dst[4 * i + G] = g;
dst[4 * i + R] = r;
dst[4 * i + A] = a;
}
left[B] = b;
left[G] = g;
left[R] = r;
left[A] = a;
}
av_cold void ff_huffyuvdsp_init(HuffYUVDSPContext *c, enum AVPixelFormat pix_fmt)
{
c->add_int16 = add_int16_c;
c->add_hfyu_median_pred_int16 = add_hfyu_median_pred_int16_c;
c->add_hfyu_left_pred_bgr32 = add_hfyu_left_pred_bgr32_c;
#if ARCH_X86
ff_huffyuvdsp_init_x86(c, pix_fmt);
#endif
}