3 * copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
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.
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.
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
22 #ifndef FFMPEG_AVFILTER_H
23 #define FFMPEG_AVFILTER_H
28 typedef struct AVFilterContext AVFilterContext;
29 typedef struct AVFilterLink AVFilterLink;
30 typedef struct AVFilterPad AVFilterPad;
32 /* TODO: look for other flags which may be useful in this structure (interlace
36 * A reference-counted picture data type used by the filter system. Filters
37 * should not store pointers to this structure directly, but instead use the
38 * AVFilterPicRef structure below
40 typedef struct AVFilterPic
42 uint8_t *data[4]; ///< picture data for each plane
43 int linesize[4]; ///< number of bytes per line
44 enum PixelFormat format; ///< colorspace
46 unsigned refcount; ///< number of references to this image
48 /** private data to be used by a custom free function */
51 * A pointer to the function to deallocate this image if the default
52 * function is not sufficient. This could, for example, add the memory
53 * back into a memory pool to be reused later without the overhead of
54 * reallocating it from scratch.
56 void (*free)(struct AVFilterPic *pic);
60 * A reference to an AVFilterPic. Since filters can manipulate the origin of
61 * a picture to, for example, crop image without any memcpy, the picture origin
62 * and dimensions are per-reference properties. Linesize is also useful for
63 * image flipping, frame to field filters, etc, and so is also per-reference.
65 * TODO: add anything necessary for frame reordering
67 typedef struct AVFilterPicRef
69 AVFilterPic *pic; ///< the picture that this is a reference to
70 uint8_t *data[4]; ///< picture data for each plane
71 int linesize[4]; ///< number of bytes per line
72 int w; ///< image width
73 int h; ///< image height
75 int64_t pts; ///< presentation timestamp in units of 1/AV_TIME_BASE
77 int perms; ///< permissions
78 #define AV_PERM_READ 0x01 ///< can read from the buffer
79 #define AV_PERM_WRITE 0x02 ///< can write to the buffer
80 #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
81 #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times
85 * Add a new reference to a picture.
86 * @param ref An existing reference to the picture
87 * @param pmask A bitmask containing the allowable permissions in the new
89 * @return A new reference to the picture with the same properties as the
90 * old, excluding any permissions denied by pmask
92 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask);
95 * Remove a reference to a picture. If this is the last reference to the
96 * picture, the picture itself is also automatically freed.
97 * @param ref Reference to the picture.
99 void avfilter_unref_pic(AVFilterPicRef *ref);
102 * A filter pad used for either input or output
107 * Pad name. The name is unique among inputs and among outputs, but an
108 * input may have the same name as an output. This may be NULL if this
109 * pad has no need to ever be referenced by name.
114 * AVFilterPad type. Only video supported now, hopefully someone will
115 * add audio in the future.
118 #define AV_PAD_VIDEO 0 ///< video pad
121 * Minimum required permissions on incoming buffers. Any buffers with
122 * insufficient permissions will be automatically copied by the filter
123 * system to a new buffer which provides the needed access permissions.
130 * Permissions which are not accepted on incoming buffers. Any buffer
131 * which has any of these permissions set be automatically copied by the
132 * filter system to a new buffer which does not have those permissions.
133 * This can be used to easily disallow buffers with AV_PERM_REUSE.
140 * Callback to get a list of supported formats. The returned list should
141 * be terminated by -1 (see avfilter_make_format_list for an easy way to
142 * create such a list).
144 * This is used for both input and output pads. If ommitted from an output
145 * pad, it is assumed that the only format supported is the same format
146 * that is being used for the filter's first input. If the filter has no
147 * inputs, then this may not be ommitted for its output pads.
149 int *(*query_formats)(AVFilterLink *link);
152 * Callback called before passing the first slice of a new frame. If
153 * NULL, the filter layer will default to storing a reference to the
154 * picture inside the link structure.
156 * Input video pads only.
158 void (*start_frame)(AVFilterLink *link, AVFilterPicRef *picref);
161 * Callback function to get a buffer. If NULL, the filter system will
162 * handle buffer requests.
164 * Input video pads only.
166 AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);
169 * Callback called after the slices of a frame are completely sent. If
170 * NULL, the filter layer will default to releasing the reference stored
171 * in the link structure during start_frame().
173 * Input video pads only.
175 void (*end_frame)(AVFilterLink *link);
178 * Slice drawing callback. This is where a filter receives video data
179 * and should do its processing.
181 * Input video pads only.
183 void (*draw_slice)(AVFilterLink *link, int y, int height);
186 * Frame request callback. A call to this should result in at least one
187 * frame being output over the given link. This should return zero on
188 * success, and another value on error.
190 * Output video pads only.
192 int (*request_frame)(AVFilterLink *link);
195 * Link configuration callback.
197 * For output pads, this should set the link properties such as
198 * width/height. This should NOT set the format property - that is
199 * negotiated between filters by the filter system using the
200 * query_formats() callback before this function is called.
202 * For input pads, this should check the properties of the link, and update
203 * the filter's internal state as necessary.
205 * For both input and output filters, this should return zero on success,
206 * and another value on error.
208 int (*config_props)(AVFilterLink *link);
211 /** Default handler for start_frame() for video inputs */
212 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
213 /** Default handler for end_frame() for video inputs */
214 void avfilter_default_end_frame(AVFilterLink *link);
215 /** Default handler for config_props() for video outputs */
216 int avfilter_default_config_output_link(AVFilterLink *link);
217 /** Default handler for config_props() for video inputs */
218 int avfilter_default_config_input_link (AVFilterLink *link);
219 /** Default handler for query_formats() for video outputs */
220 int *avfilter_default_query_output_formats(AVFilterLink *link);
221 /** Default handler for get_video_buffer() for video inputs */
222 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,
226 * Filter definition. This defines the pads a filter contains, and all the
227 * callback functions used to interact with the filter.
231 char *name; ///< filter name
232 char *author; ///< filter author
234 int priv_size; ///< size of private data to allocate for the filter
237 * Filter initialization function. Args contains the user-supplied
238 * parameters. FIXME: maybe an AVOption-based system would be better?
239 * opaque is data provided by the code requesting creation of the filter,
240 * and is used to pass data to the filter.
242 int (*init)(AVFilterContext *ctx, const char *args, void *opaque);
245 * Filter uninitialization function. Should deallocate any memory held
246 * by the filter, release any picture references, etc. This does not need
247 * to deallocate the AVFilterContext->priv memory itself.
249 void (*uninit)(AVFilterContext *ctx);
251 const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none
252 const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none
255 /** An instance of a filter */
256 struct AVFilterContext
258 AVClass *av_class; ///< Needed for av_log()
260 AVFilter *filter; ///< The AVFilter of which this is an instance
262 char *name; ///< name of this filter instance
264 unsigned input_count; ///< number of input pads
265 AVFilterPad *input_pads; ///< array of input pads
266 AVFilterLink **inputs; ///< array of pointers to input links
268 unsigned output_count; ///< number of output pads
269 AVFilterPad *output_pads; ///< array of output pads
270 AVFilterLink **outputs; ///< array of pointers to output links
272 void *priv; ///< private data for use by the filter
276 * A links between two filters. This contains pointers to the source and
277 * destination filters between which this link exists, and the indices of
278 * the pads involved. In addition, this link also contains the parameters
279 * which have been negotiated and agreed upon between the filter, such as
280 * image dimensions, format, etc
284 AVFilterContext *src; ///< source filter
285 unsigned int srcpad; ///< index of the output pad on the source filter
287 AVFilterContext *dst; ///< dest filter
288 unsigned int dstpad; ///< index of the input pad on the dest filter
290 int w; ///< agreed upon image width
291 int h; ///< agreed upon image height
292 enum PixelFormat format; ///< agreed upon image colorspace
295 * The picture reference currently being sent across the link by the source
296 * filter. This is used internally by the filter system to allow
297 * automatic copying of pictures which d not have sufficient permissions
298 * for the destination. This should not be accessed directly by the
301 AVFilterPicRef *srcpic;
303 AVFilterPicRef *cur_pic;
304 AVFilterPicRef *outpic;
308 * Link two filters together
309 * @param src The source filter
310 * @param srcpad Index of the output pad on the source filter
311 * @param dst The destination filter
312 * @param dstpad Index of the input pad on the destination filter
313 * @return Zero on success
315 int avfilter_link(AVFilterContext *src, unsigned srcpad,
316 AVFilterContext *dst, unsigned dstpad);
319 * Negotiate the colorspace, dimensions, etc of a link
320 * @param link The link to negotiate the properties of
321 * @return Zero on successful negotiation
323 int avfilter_config_link(AVFilterLink *link);
326 * Request a picture buffer with a specific set of permissions
327 * @param link The output link to the filter from which the picture will
329 * @param perms The required access permissions
330 * @return A reference to the picture. This must be unreferenced with
331 * avfilter_unref_pic when you are finished with it.
333 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);
336 * Request an input frame from the filter at the other end of the link.
337 * @param link The input link
338 * @return Zero on success
340 int avfilter_request_frame(AVFilterLink *link);
343 * Notify the next filter of the start of a frame.
344 * @param link The output link the frame will be sent over
345 * @param picref A reference to the frame about to be sent. The data for this
346 * frame need only be valid once draw_slice() is called for that
347 * portion. The receiving filter will free this reference when
348 * it no longer needs it.
350 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref);
353 * Notify the next filter that the current frame has finished
354 * @param link The output link the frame was sent over
356 void avfilter_end_frame(AVFilterLink *link);
359 * Send a slice to the next filter
360 * @param link The output link over which the frame is being sent
361 * @param y Offset in pixels from the top of the image for this slice
362 * @param h Height of this slice in pixels
364 void avfilter_draw_slice(AVFilterLink *link, int y, int h);
366 /** Initialize the filter system. Registers all builtin filters */
367 void avfilter_init(void);
369 /** Uninitialize the filter system. Unregisters all filters */
370 void avfilter_uninit(void);
373 * Register a filter. This is only needed if you plan to use
374 * avfilter_get_by_name later to lookup the AVFilter structure by name. A
375 * filter can still by instantiated with avfilter_open even if it is not
377 * @param filter The filter to register
379 void avfilter_register(AVFilter *filter);
382 * Gets a filter definition matching the given name
383 * @param name The filter name to find
384 * @return The filter definition, if any matching one is registered.
385 * NULL if none found.
387 AVFilter *avfilter_get_by_name(char *name);
390 * Create a filter instance
391 * @param filter The filter to create an instance of
392 * @param inst_name Name to give to the new instance. Can be NULL for none.
393 * @return Pointer to the new instance on success. NULL on failure.
395 AVFilterContext *avfilter_open(AVFilter *filter, char *inst_name);
398 * Initialize a filter
399 * @param filter The filter to initialize
400 * @param args A string of parameters to use when initializing the filter.
401 * The format and meaning of this string varies by filter.
402 * @param opaque Any extra non-string data needed by the filter. The meaning
403 * of this parameter varies by filter.
404 * @return Zero on success
406 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
410 * @param filter The filter to destroy
412 void avfilter_destroy(AVFilterContext *filter);
415 * Helper function to create a list of supported formats. This is intended
416 * for use in AVFilterPad->query_formats().
417 * @param len The number of formats supported
418 * @param ... A list of the supported formats
419 * @return The format list in a form suitable for returning from
420 * AVFilterPad->query_formats()
422 int *avfilter_make_format_list(int len, ...);
426 * @param idx Insertion point. Pad is inserted at the end if this point
427 * is beyond the end of the list of pads.
428 * @param count Pointer to the number of pads in the list
429 * @param padidx_off Offset within an AVFilterLink structure to the element
430 * to increment when inserting a new pad causes link
431 * numbering to change
432 * @param pads Pointer to the pointer to the beginning of the list of pads
433 * @param links Pointer to the pointer to the beginning of the list of links
434 * @param newpad The new pad to add. A copy is made when adding.
436 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
437 AVFilterPad **pads, AVFilterLink ***links,
438 AVFilterPad *newpad);
440 /** insert a new input pad for the filter */
441 static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index,
444 avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad),
445 &f->input_pads, &f->inputs, p);
448 /** insert a new output pad for the filter */
449 static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index,
452 avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad),
453 &f->output_pads, &f->outputs, p);
456 #endif /* FFMPEG_AVFILTER_H */