FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vf_field.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2003 Rich Felker
3  * Copyright (c) 2012 Stefano Sabatini
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * field filter, based on libmpcodecs/vf_field.c by Rich Felker
25  */
26 
27 #include "libavutil/opt.h"
28 #include "libavutil/pixdesc.h"
29 #include "avfilter.h"
30 #include "internal.h"
31 
33 
34 typedef struct {
35  const AVClass *class;
36  int type; ///< FieldType
37  int nb_planes; ///< number of planes of the current format
38 } FieldContext;
39 
40 #define OFFSET(x) offsetof(FieldContext, x)
41 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
42 
43 static const AVOption field_options[] = {
44  {"type", "set field type (top or bottom)", OFFSET(type), AV_OPT_TYPE_INT, {.i64=FIELD_TYPE_TOP}, 0, 1, FLAGS, "field_type" },
45  {"top", "select top field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_TOP}, INT_MIN, INT_MAX, FLAGS, "field_type"},
46  {"bottom", "select bottom field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "field_type"},
47  {NULL}
48 };
49 
51 
52 static int config_props_output(AVFilterLink *outlink)
53 {
54  AVFilterContext *ctx = outlink->src;
55  FieldContext *field = ctx->priv;
56  AVFilterLink *inlink = ctx->inputs[0];
57 
58  field->nb_planes = av_pix_fmt_count_planes(outlink->format);
59 
60  outlink->w = inlink->w;
61  outlink->h = (inlink->h + (field->type == FIELD_TYPE_TOP)) / 2;
62 
63  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d type:%s -> w:%d h:%d\n",
64  inlink->w, inlink->h, field->type == FIELD_TYPE_BOTTOM ? "bottom" : "top",
65  outlink->w, outlink->h);
66  return 0;
67 }
68 
69 static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
70 {
71  FieldContext *field = inlink->dst->priv;
72  AVFilterLink *outlink = inlink->dst->outputs[0];
73  int i;
74 
75  inpicref->height = outlink->h;
76  inpicref->interlaced_frame = 0;
77 
78  for (i = 0; i < field->nb_planes; i++) {
79  if (field->type == FIELD_TYPE_BOTTOM)
80  inpicref->data[i] = inpicref->data[i] + inpicref->linesize[i];
81  inpicref->linesize[i] = 2 * inpicref->linesize[i];
82  }
83  return ff_filter_frame(outlink, inpicref);
84 }
85 
86 static const AVFilterPad field_inputs[] = {
87  {
88  .name = "default",
89  .type = AVMEDIA_TYPE_VIDEO,
90  .filter_frame = filter_frame,
91  },
92  { NULL }
93 };
94 
95 static const AVFilterPad field_outputs[] = {
96  {
97  .name = "default",
98  .type = AVMEDIA_TYPE_VIDEO,
99  .config_props = config_props_output,
100  },
101  { NULL }
102 };
103 
105  .name = "field",
106  .description = NULL_IF_CONFIG_SMALL("Extract a field from the input video."),
107  .priv_size = sizeof(FieldContext),
108  .inputs = field_inputs,
109  .outputs = field_outputs,
110  .priv_class = &field_class,
111 };
#define NULL
Definition: coverity.c:32
#define FLAGS
Definition: vf_field.c:41
static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
Definition: vf_field.c:69
This structure describes decoded (raw) audio or video data.
Definition: frame.h:190
static const AVFilterPad field_inputs[]
Definition: vf_field.c:86
AVOption.
Definition: opt.h:246
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2372
Main libavfilter public API header.
#define OFFSET(x)
Definition: vf_field.c:40
const char * name
Pad name.
Definition: internal.h:59
static const AVOption field_options[]
Definition: vf_field.c:43
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:315
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1189
AVOptions.
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
int interlaced_frame
The content of the picture is interlaced.
Definition: frame.h:328
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:53
FieldType
Definition: interlace.h:42
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
void * priv
private data for use by the filter
Definition: avfilter.h:322
int type
FieldType.
Definition: vf_field.c:36
AVFormatContext * ctx
Definition: movenc.c:48
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
AVFILTER_DEFINE_CLASS(field)
static int config_props_output(AVFilterLink *outlink)
Definition: vf_field.c:52
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:221
GLint GLenum type
Definition: opengl_enc.c:105
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
int nb_planes
number of planes of the current format
Definition: vf_field.c:37
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:319
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:204
An instance of a filter.
Definition: avfilter.h:307
int height
Definition: frame.h:242
static const AVFilterPad field_outputs[]
Definition: vf_field.c:95
AVFilter ff_vf_field
Definition: vf_field.c:104
internal API functions