FFmpeg: libavfilter/boxblur.c Source File

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libavfilter

boxblur.c

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1 /*

5 *

6 * This file is part of FFmpeg.

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 #include "libavutil/mem.h"

24 #include "boxblur.h"

26 static const char *const var_names[] = {

27 "w",

28 "h",

29 "cw",

30 "ch",

31 "hsub",

32 "vsub",

33 NULL

34 };

36 enum var_name {

37 VAR_W,

38 VAR_H,

39 VAR_CW,

40 VAR_CH,

41 VAR_HSUB,

42 VAR_VSUB,

43 VARS_NB

44 };

47 int ff_boxblur_eval_filter_params(AVFilterLink *inlink,

48 FilterParam *luma_param,

49 FilterParam *chroma_param,

50 FilterParam *alpha_param)

51 {

52 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

53 AVFilterContext *ctx = inlink->dst;

54 int w = inlink->w, h = inlink->h;

55 int cw, ch;

56 double var_values[VARS_NB], res;

57 char *expr;

58 int ret;

60 if (!luma_param->radius_expr) {

61 av_log(ctx, AV_LOG_ERROR, "Luma radius expression is not set.\n");

62 return AVERROR(EINVAL);

63 }

65 /* fill missing params */

66 if (!chroma_param->radius_expr) {

67 chroma_param->radius_expr = av_strdup(luma_param->radius_expr);

68 if (!chroma_param->radius_expr)

69 return AVERROR(ENOMEM);

70 }

71 if (chroma_param->power < 0)

72 chroma_param->power = luma_param->power;

74 if (!alpha_param->radius_expr) {

75 alpha_param->radius_expr = av_strdup(luma_param->radius_expr);

76 if (!alpha_param->radius_expr)

77 return AVERROR(ENOMEM);

78 }

79 if (alpha_param->power < 0)

80 alpha_param->power = luma_param->power;

82 var_values[VAR_W] = inlink->w;

83 var_values[VAR_H] = inlink->h;

84 var_values[VAR_CW] = cw = w>>(desc->log2_chroma_w);

85 var_values[VAR_CH] = ch = h>>(desc->log2_chroma_h);

86 var_values[VAR_HSUB] = 1<<(desc->log2_chroma_w);

87 var_values[VAR_VSUB] = 1<<(desc->log2_chroma_h);

89 #define EVAL_RADIUS_EXPR(comp) \

90 expr = comp->radius_expr; \

91 ret = av_expr_parse_and_eval(&res, expr, var_names, var_values, \

92 NULL, NULL, NULL, NULL, NULL, 0, ctx); \

93 comp->radius = res; \

94 if (ret < 0) { \

95 av_log(ctx, AV_LOG_ERROR, \

96 "Error when evaluating " #comp " radius expression '%s'\n", expr); \

97 return ret; \

98 }

100 EVAL_RADIUS_EXPR(luma_param);

101 EVAL_RADIUS_EXPR(chroma_param);

102 EVAL_RADIUS_EXPR(alpha_param);

103

104 av_log(ctx, AV_LOG_VERBOSE,

105 "luma_radius:%d luma_power:%d "

106 "chroma_radius:%d chroma_power:%d "

107 "alpha_radius:%d alpha_power:%d "

108 "w:%d chroma_w:%d h:%d chroma_h:%d\n",

109 luma_param ->radius, luma_param ->power,

110 chroma_param->radius, chroma_param->power,

111 alpha_param ->radius, alpha_param ->power,

112 w, cw, h, ch);

113

114

115 #define CHECK_RADIUS_VAL(w_, h_, comp) \

116 if (comp->radius < 0 || \

117 2*comp->radius > FFMIN(w_, h_)) { \

118 av_log(ctx, AV_LOG_ERROR, \

119 "Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \

120 comp->radius, FFMIN(w_, h_)/2); \

121 return AVERROR(EINVAL); \

122 }

123 CHECK_RADIUS_VAL(w, h, luma_param);

124 CHECK_RADIUS_VAL(cw, ch, chroma_param);

125 CHECK_RADIUS_VAL(w, h, alpha_param);

126

127 return 0;

128 }

AVERROR

Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions

VAR_CH

@ VAR_CH

Definition: boxblur.c:40

var_name

Definition: noise.c:46

CHECK_RADIUS_VAL

#define CHECK_RADIUS_VAL(w_, h_, comp)

av_pix_fmt_desc_get

const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)

Definition: pixdesc.c:3456

inlink

The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink

Definition: filter_design.txt:212

uint8_t w

Definition: llviddspenc.c:38

FilterParam::radius_expr

char * radius_expr

Definition: boxblur.h:34

VAR_HSUB

@ VAR_HSUB

Definition: boxblur.c:41

AV_LOG_VERBOSE

#define AV_LOG_VERBOSE

Detailed information.