FFmpeg
fdctdsp.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 "avcodec.h"
21 #include "dct.h"
22 #include "faandct.h"
23 #include "fdctdsp.h"
24 #include "config.h"
25 
27 {
28  const unsigned high_bit_depth = avctx->bits_per_raw_sample > 8;
29 
30  if (avctx->bits_per_raw_sample == 10 || avctx->bits_per_raw_sample == 9) {
31  c->fdct = ff_jpeg_fdct_islow_10;
32  c->fdct248 = ff_fdct248_islow_10;
33  } else if (avctx->dct_algo == FF_DCT_FASTINT) {
34  c->fdct = ff_fdct_ifast;
35  c->fdct248 = ff_fdct_ifast248;
36 #if CONFIG_FAANDCT
37  } else if (avctx->dct_algo == FF_DCT_FAAN) {
38  c->fdct = ff_faandct;
39  c->fdct248 = ff_faandct248;
40 #endif /* CONFIG_FAANDCT */
41  } else {
42  c->fdct = ff_jpeg_fdct_islow_8; // slow/accurate/default
43  c->fdct248 = ff_fdct248_islow_8;
44  }
45 
46  if (ARCH_PPC)
47  ff_fdctdsp_init_ppc(c, avctx, high_bit_depth);
48  if (ARCH_X86)
49  ff_fdctdsp_init_x86(c, avctx, high_bit_depth);
50 }
FF_DCT_FAAN
#define FF_DCT_FAAN
Definition: avcodec.h:1390
ff_fdct248_islow_8
void ff_fdct248_islow_8(int16_t *data)
FDCTDSPContext
Definition: fdctdsp.h:26
faandct.h
Floating point AAN DCT.
AVCodecContext::dct_algo
int dct_algo
DCT algorithm, see FF_DCT_* below.
Definition: avcodec.h:1384
av_cold
#define av_cold
Definition: attributes.h:90
dct.h
ff_fdctdsp_init
av_cold void ff_fdctdsp_init(FDCTDSPContext *c, AVCodecContext *avctx)
Definition: fdctdsp.c:26
ff_fdct_ifast248
void ff_fdct_ifast248(int16_t *data)
Definition: jfdctfst.c:274
AVCodecContext::bits_per_raw_sample
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:1425
ff_faandct
void ff_faandct(int16_t *data)
Definition: faandct.c:114
ff_fdct_ifast
void ff_fdct_ifast(int16_t *data)
Definition: jfdctfst.c:208
ff_jpeg_fdct_islow_8
void ff_jpeg_fdct_islow_8(int16_t *data)
ff_fdctdsp_init_ppc
av_cold void ff_fdctdsp_init_ppc(FDCTDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: fdctdsp.c:464
ff_fdct248_islow_10
void ff_fdct248_islow_10(int16_t *data)
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
ff_jpeg_fdct_islow_10
void ff_jpeg_fdct_islow_10(int16_t *data)
ff_fdctdsp_init_x86
void ff_fdctdsp_init_x86(FDCTDSPContext *c, AVCodecContext *avctx, unsigned high_bit_depth)
Definition: fdctdsp_init.c:26
attributes.h
fdctdsp.h
FF_DCT_FASTINT
#define FF_DCT_FASTINT
Definition: avcodec.h:1386
avcodec.h
AVCodecContext
main external API structure.
Definition: avcodec.h:383
ff_faandct248
void ff_faandct248(int16_t *data)
Definition: faandct.c:168