Make input/output pads modifiable on a per-instance basis.
[libav.git] / libavfilter / avfilter.h
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1/*
2 * Filter layer
3 * copyright (c) 2007 Bobby Bingham
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#ifndef FFMPEG_AVFILTER_H
23#define FFMPEG_AVFILTER_H
24
25#include "avcodec.h"
26
27typedef struct AVFilterContext AVFilterContext;
28typedef struct AVFilterLink AVFilterLink;
29typedef struct AVFilterPad AVFilterPad;
30
31/* TODO: look for other flags which may be useful in this structure (interlace
32 * flags, etc)
33 */
34/**
35 * A reference-counted picture data type used by the filter system. Filters
36 * should not store pointers to this structure directly, but instead use the
37 * AVFilterPicRef structure below
38 */
39typedef struct AVFilterPic
40{
41 uint8_t *data[4];
42 int linesize[4]; ///< number of bytes per line
43 enum PixelFormat format;
44
45 unsigned refcount;
46 void *priv;
47 void (*free)(struct AVFilterPic *pic);
48} AVFilterPic;
49
50/**
51 * A reference to an AVFilterPic. Since filters can manipulate the origin of
52 * a picture to, for example, crop image without any memcpy, the picture origin
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53 * and dimensions are per-reference properties. Linesize is also useful for
54 * image flipping, frame to field filters, etc, and so is also per-reference.
a5cbb2f4 55 *
1a18860a 56 * TODO: add anything necessary for frame reordering
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57 */
58typedef struct AVFilterPicRef
59{
60 AVFilterPic *pic;
61 uint8_t *data[4];
bbf42679 62 int linesize[4];
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63 int w, h;
64
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65 int64_t pts; ///< presentation timestamp in milliseconds
66
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67 int perms; ///< permissions
68#define AV_PERM_READ 0x01 ///< can read from the buffer
69#define AV_PERM_WRITE 0x02 ///< can write to the buffer
70#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
71#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times
72} AVFilterPicRef;
73
74/**
75 * Add a new reference to a picture.
76 * @param ref An existing reference to the picture
8fb48e7c 77 * @param pmask A bitmask containing the allowable permissions in the new reference
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78 * @return A new reference to the picture with the same properties as the old
79 */
8fb48e7c 80AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
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81
82/**
83 * Remove a reference to a picture. If this is the last reference to the
84 * picture, the picture itself is also automatically freed.
85 * @param ref Reference to the picture.
86 */
87void avfilter_unref_pic(AVFilterPicRef *ref);
88
89struct AVFilterPad
90{
91 /**
92 * Pad name. The name is unique among inputs and among oututs, but an
93 * input may have the same name as an output.
94 */
95 char *name;
96
97 /**
98 * AVFilterPad type. Only video supported now, hopefully someone will
99 * add audio in the future.
100 */
101 int type;
102#define AV_PAD_VIDEO 0
103
104 /**
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105 * Callback to get a list of supported formats. The returned list should
106 * be terminated by -1. This is used for both input and output pads and
107 * is required for both.
108 */
109 int *(*query_formats)(AVFilterLink *link);
110
111 /**
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112 * Callback called before passing the first slice of a new frame. If
113 * NULL, the filter layer will default to storing a reference to the
114 * picture inside the link structure.
115 */
116 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
117
118 /**
119 * Callback function to get a buffer. If NULL, the filter system will
120 * handle buffer requests. Only required for input video pads.
121 */
122 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
123
124 /**
125 * Callback called after the slices of a frame are completely sent. If
126 * NULL, the filter layer will default to releasing the reference stored
127 * in the link structure during start_frame().
128 */
129 void (*end_frame)(AVFilterLink *link);
130
131 /**
132 * Slice drawing callback. This is where a filter receives video data
133 * and should do its processing. Only required for input video pads.
134 */
135 void (*draw_slice)(AVFilterLink *link, uint8_t *data[4], int y, int height);
136
137 /**
138 * Frame request callback. A call to this should result in at least one
139 * frame being output over the given link. Video output pads only.
140 */
141 void (*request_frame)(AVFilterLink *link);
142
143 /**
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144 * Link configuration callback. For output pads, this should set the link
145 * properties such as width/height. NOTE: this should not set the format
146 * property - that is negotiated between filters by the filter system using
147 * the query_formats() callback.
148 *
149 * For input pads, this should check the properties of the link, and update
150 * the filter's internal state as necessary.
a5cbb2f4 151 */
d3e57c15 152 int (*config_props)(AVFilterLink *link);
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153};
154
155/* the default implementations of start_frame() and end_frame() */
156void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
157void avfilter_default_end_frame(AVFilterLink *link);
158
159typedef struct
160{
161 char *name;
162 char *author;
163
164 int priv_size;
165
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166 /**
167 * Filter initialization function. Args contains the user-supplied
168 * parameters. FIXME: maybe an AVOption-based system would be better?
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169 * opaque is data provided by the code requesting creation of the filter,
170 * and is used to pass data to the filter.
4d96a914 171 */
95bcf498 172 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
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173 void (*uninit)(AVFilterContext *ctx);
174
175 const AVFilterPad *inputs; /// NULL terminated list of inputs. NULL if none
176 const AVFilterPad *outputs; /// NULL terminated list of outputs. NULL if none
177} AVFilter;
178
179struct AVFilterContext
180{
181 AVClass *av_class;
182
183 AVFilter *filter;
184
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185 char *name;
186
25f8e601 187 unsigned input_count;
7c9066a3 188 AVFilterPad *input_pads;
a5cbb2f4 189 AVFilterLink **inputs;
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190
191 unsigned output_count;
7c9066a3 192 AVFilterPad *output_pads;
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193 AVFilterLink **outputs;
194
195 void *priv;
196};
197
198struct AVFilterLink
199{
200 AVFilterContext *src;
201 unsigned int srcpad;
202
203 AVFilterContext *dst;
204 unsigned int dstpad;
205
206 int w, h;
207 enum PixelFormat format;
208
209 AVFilterPicRef *cur_pic;
462f57db 210 AVFilterPicRef *outpic;
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211};
212
213/** Link two filters together */
214int avfilter_link(AVFilterContext *src, unsigned srcpad,
215 AVFilterContext *dst, unsigned dstpad);
216
217AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
218void avfilter_request_frame(AVFilterLink *link);
219void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
220void avfilter_end_frame(AVFilterLink *link);
221void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h);
222
223void avfilter_init(void);
224void avfilter_uninit(void);
225void avfilter_register(AVFilter *filter);
226AVFilter *avfilter_get_by_name(char *name);
227
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228AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name);
229AVFilterContext *avfilter_create_by_name(char *name, char *inst_name);
6e365c57 230int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
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231void avfilter_destroy(AVFilterContext *filter);
232
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233int *avfilter_make_format_list(int len, ...);
234
a5cbb2f4 235#endif /* FFMPEG_AVFILTER_H */