FFmpeg
ttaencdsp.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "libavutil/attributes.h"
20 #include "ttaencdsp.h"
21 #include "config.h"
22 
23 static void ttaenc_filter_process_c(int32_t *qm, int32_t *dx, int32_t *dl,
25  int32_t round) {
26  if (*error < 0) {
27  qm[0] -= dx[0]; qm[1] -= dx[1]; qm[2] -= dx[2]; qm[3] -= dx[3];
28  qm[4] -= dx[4]; qm[5] -= dx[5]; qm[6] -= dx[6]; qm[7] -= dx[7];
29  } else if (*error > 0) {
30  qm[0] += dx[0]; qm[1] += dx[1]; qm[2] += dx[2]; qm[3] += dx[3];
31  qm[4] += dx[4]; qm[5] += dx[5]; qm[6] += dx[6]; qm[7] += dx[7];
32  }
33 
34  round += dl[0] * qm[0] + dl[1] * qm[1] + dl[2] * qm[2] + dl[3] * qm[3] +
35  dl[4] * qm[4] + dl[5] * qm[5] + dl[6] * qm[6] + dl[7] * qm[7];
36 
37  dx[0] = dx[1]; dx[1] = dx[2]; dx[2] = dx[3]; dx[3] = dx[4];
38  dl[0] = dl[1]; dl[1] = dl[2]; dl[2] = dl[3]; dl[3] = dl[4];
39 
40  dx[4] = ((dl[4] >> 30) | 1);
41  dx[5] = ((dl[5] >> 30) | 2) & ~1;
42  dx[6] = ((dl[6] >> 30) | 2) & ~1;
43  dx[7] = ((dl[7] >> 30) | 4) & ~3;
44 
45  dl[4] = -dl[5]; dl[5] = -dl[6];
46  dl[6] = *in - dl[7]; dl[7] = *in;
47  dl[5] += dl[6]; dl[4] += dl[5];
48 
49  *in -= (round >> shift);
50  *error = *in;
51 }
52 
54 {
55  c->filter_process = ttaenc_filter_process_c;
56 
57  if (ARCH_X86)
59 }
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:31
ff_ttaencdsp_init
av_cold void ff_ttaencdsp_init(TTAEncDSPContext *c)
Definition: ttaencdsp.c:53
ttaenc_filter_process_c
static void ttaenc_filter_process_c(int32_t *qm, int32_t *dx, int32_t *dl, int32_t *error, int32_t *in, int32_t shift, int32_t round)
Definition: ttaencdsp.c:23
av_cold
#define av_cold
Definition: attributes.h:90
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
attributes.h
ff_ttaencdsp_init_x86
void ff_ttaencdsp_init_x86(TTAEncDSPContext *c)
Definition: ttaencdsp_init.c:33
round
static av_always_inline av_const double round(double x)
Definition: libm.h:444
shift
static int shift(int a, int b)
Definition: sonic.c:83
TTAEncDSPContext
Definition: ttaencdsp.h:24
int32_t
int32_t
Definition: audioconvert.c:56
ttaencdsp.h