FFmpeg
lpc_init.c
Go to the documentation of this file.
1 /*
2  * Copyright © 2022 Rémi Denis-Courmont.
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "config.h"
22 
23 #include "libavutil/attributes.h"
24 #include "libavutil/cpu.h"
25 #include "libavutil/riscv/cpu.h"
26 #include "libavcodec/lpc.h"
27 
28 void ff_lpc_apply_welch_window_rvv(const int32_t *, ptrdiff_t, double *);
29 void ff_lpc_compute_autocorr_rvv(const double *, ptrdiff_t, int, double *);
30 
32 {
33 #if HAVE_RVV && (__riscv_xlen >= 64)
34  int flags = av_get_cpu_flags();
35 
37  c->lpc_apply_welch_window = ff_lpc_apply_welch_window_rvv;
38 
39  if (ff_get_rv_vlenb() > c->max_order)
40  c->lpc_compute_autocorr = ff_lpc_compute_autocorr_rvv;
41  }
42 #endif
43 }
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:109
lpc.h
AV_CPU_FLAG_RVV_F64
#define AV_CPU_FLAG_RVV_F64
Vectors of double's.
Definition: cpu.h:95
LPCContext
Definition: lpc.h:51
AV_CPU_FLAG_RVB
#define AV_CPU_FLAG_RVB
B (bit manipulations)
Definition: cpu.h:102
av_cold
#define av_cold
Definition: attributes.h:90
cpu.h
ff_lpc_compute_autocorr_rvv
void ff_lpc_compute_autocorr_rvv(const double *, ptrdiff_t, int, double *)
ff_lpc_apply_welch_window_rvv
void ff_lpc_apply_welch_window_rvv(const int32_t *, ptrdiff_t, double *)
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
cpu.h
ff_lpc_init_riscv
av_cold void ff_lpc_init_riscv(LPCContext *c)
Definition: lpc_init.c:31
attributes.h
int32_t
int32_t
Definition: audioconvert.c:56
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482