FFmpeg  4.0
gamma.c
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1 /*
2  * Copyright (C) 2015 Pedro Arthur <bygrandao@gmail.com>
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 "swscale_internal.h"
22 
23 typedef struct GammaContext
24 {
25  uint16_t *table;
26 } GammaContext;
27 
28 // gamma_convert expects 16 bit rgb format
29 // it writes directly in src slice thus it must be modifiable (done through cascade context)
30 static int gamma_convert(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
31 {
32  GammaContext *instance = desc->instance;
33  uint16_t *table = instance->table;
34  int srcW = desc->src->width;
35 
36  int i;
37  for (i = 0; i < sliceH; ++i) {
38  uint8_t ** src = desc->src->plane[0].line;
39  int src_pos = sliceY+i - desc->src->plane[0].sliceY;
40 
41  uint16_t *src1 = (uint16_t*)*(src+src_pos);
42  int j;
43  for (j = 0; j < srcW; ++j) {
44  uint16_t r = AV_RL16(src1 + j*4 + 0);
45  uint16_t g = AV_RL16(src1 + j*4 + 1);
46  uint16_t b = AV_RL16(src1 + j*4 + 2);
47 
48  AV_WL16(src1 + j*4 + 0, table[r]);
49  AV_WL16(src1 + j*4 + 1, table[g]);
50  AV_WL16(src1 + j*4 + 2, table[b]);
51  }
52 
53  }
54  return sliceH;
55 }
56 
57 
59 {
60  GammaContext *li = av_malloc(sizeof(GammaContext));
61  if (!li)
62  return AVERROR(ENOMEM);
63  li->table = table;
64 
65  desc->instance = li;
66  desc->src = src;
67  desc->dst = NULL;
68  desc->process = &gamma_convert;
69 
70  return 0;
71 }
72 
int ff_init_gamma_convert(SwsFilterDescriptor *desc, SwsSlice *src, uint16_t *table)
initializes gamma conversion descriptor
Definition: gamma.c:58
#define NULL
Definition: coverity.c:32
const char * g
Definition: vf_curves.c:112
const char * desc
Definition: nvenc.c:65
Struct which holds all necessary data for processing a slice.
const char * b
Definition: vf_curves.c:113
#define AV_RL16
Definition: intreadwrite.h:42
#define src
Definition: vp8dsp.c:254
uint8_t
#define av_malloc(s)
uint8_t ** line
line buffer
SwsSlice * dst
Output slice.
#define AVERROR(e)
Definition: error.h:43
uint16_t * table
Definition: gamma.c:25
const char * r
Definition: vf_curves.c:111
SwsPlane plane[MAX_SLICE_PLANES]
color planes
#define src1
Definition: h264pred.c:139
int width
Slice line width.
int(* process)(SwsContext *c, struct SwsFilterDescriptor *desc, int sliceY, int sliceH)
Function for processing input slice sliceH lines starting from line sliceY.
Struct which defines a slice of an image to be scaled or an output for a scaled slice.
void * instance
Filter instance data.
static double c[64]
#define AV_WL16(p, v)
Definition: intreadwrite.h:412
static int gamma_convert(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
Definition: gamma.c:30
SwsSlice * src
Source slice.
int sliceY
index of first line