libavfilter/avfilter.c

   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 #include <stdlib.h>
  23 #include <string.h>
  24 #include <stdio.h>
  25
  26 #include "avfilter.h"
  27
  28 /** list of registered filters, sorted by name */
  29 static int filter_count = 0;
  30 static AVFilter **filters = NULL;
  31
  32 /* TODO: buffer pool.  see comment for avfilter_default_get_video_buffer() */
  33 void avfilter_default_free_video_buffer(AVFilterPic *pic)
  34 {
  35     avpicture_free((AVPicture *) pic);
  36     av_free(pic);
  37 }
  38
  39 /* TODO: set the buffer's priv member to a context structure for the whole
  40  * filter chain.  This will allow for a buffer pool instead of the constant
  41  * alloc & free cycle currently implemented. */
  42 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms)
  43 {
  44     AVFilterPic *pic = av_mallocz(sizeof(AVFilterPic));
  45     AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
  46
  47     ref->pic = pic;
  48     ref->w = link->w;
  49     ref->h = link->h;
  50     ref->perms = perms;
  51
  52     pic->refcount = 1;
  53     pic->format = link->format;
  54     pic->free = avfilter_default_free_video_buffer;
  55     avpicture_alloc((AVPicture *)pic, pic->format, ref->w, ref->h);
  56
  57     ref->data[0] = pic->data[0];
  58     ref->data[1] = pic->data[1];
  59     ref->data[2] = pic->data[2];
  60     ref->data[3] = pic->data[3];
  61
  62     return ref;
  63 }
  64
  65 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
  66 {
  67     link->cur_pic = picref;
  68 }
  69
  70 void avfilter_default_end_frame(AVFilterLink *link)
  71 {
  72     avfilter_unref_pic(link->cur_pic);
  73     link->cur_pic = NULL;
  74 }
  75
  76 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref)
  77 {
  78     AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
  79     memcpy(ret, ref, sizeof(AVFilterPicRef));
  80     ret->pic->refcount ++;
  81     return ret;
  82 }
  83
  84 void avfilter_unref_pic(AVFilterPicRef *ref)
  85 {
  86     if(-- ref->pic->refcount == 0)
  87         ref->pic->free(ref->pic);
  88     av_free(ref);
  89 }
  90
  91 int avfilter_link(AVFilterContext *src, unsigned srcpad,
  92                   AVFilterContext *dst, unsigned dstpad)
  93 {
  94     AVFilterLink *link;
  95
  96     if(src->outputs[srcpad] || dst->inputs[dstpad])
  97         return -1;
  98
  99     src->outputs[srcpad] =
 100     dst->inputs[dstpad]  = link = av_malloc(sizeof(AVFilterLink));
 101
 102     link->src = src;
 103     link->dst = dst;
 104     link->srcpad = srcpad;
 105     link->dstpad = dstpad;
 106     link->cur_pic = NULL;
 107
 108     src->filter->outputs[dstpad].set_video_props(link);
 109     return 0;
 110 }
 111
 112 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms)
 113 {
 114     AVFilterPicRef *ret = NULL;
 115
 116     if(link->dst->filter->inputs[link->dstpad].get_video_buffer)
 117         ret = link->dst->filter->inputs[link->dstpad].get_video_buffer(link, perms);
 118
 119     if(!ret)
 120         ret = avfilter_default_get_video_buffer(link, perms);
 121
 122     return ret;
 123 }
 124
 125 void avfilter_request_frame(AVFilterLink *link)
 126 {
 127     link->src->filter->outputs[link->srcpad].request_frame(link);
 128 }
 129
 130 /* XXX: should we do the duplicating of the picture ref here, instead of
 131  * forcing the source filter to do it? */
 132 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
 133 {
 134     void (*start_frame)(AVFilterLink *, AVFilterPicRef *);
 135
 136     start_frame = link->dst->filter->inputs[link->dstpad].start_frame;
 137     if(!start_frame)
 138         start_frame = avfilter_default_start_frame;
 139
 140     start_frame(link, picref);
 141 }
 142
 143 void avfilter_end_frame(AVFilterLink *link)
 144 {
 145     void (*end_frame)(AVFilterLink *);
 146
 147     end_frame = link->dst->filter->inputs[link->dstpad].end_frame;
 148     if(!end_frame)
 149         end_frame = avfilter_default_end_frame;
 150
 151     end_frame(link);
 152 }
 153
 154 void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h)
 155 {
 156     link->dst->filter->inputs[link->dstpad].draw_slice(link, data, y, h);
 157 }
 158
 159 static int filter_cmp(const void *aa, const void *bb)
 160 {
 161     const AVFilter *a = *(const AVFilter **)aa, *b = *(const AVFilter **)bb;
 162     return strcmp(a->name, b->name);
 163 }
 164
 165 AVFilter *avfilter_get_by_name(char *name)
 166 {
 167     AVFilter key = { .name = name, };
 168     AVFilter *key2 = &key;
 169     AVFilter **ret;
 170
 171     ret = bsearch(&key2, filters, filter_count, sizeof(AVFilter **), filter_cmp);
 172     if(ret)
 173         return *ret;
 174     return NULL;
 175 }
 176
 177 /* FIXME: insert in order, rather than insert at end + resort */
 178 void avfilter_register(AVFilter *filter)
 179 {
 180     filters = av_realloc(filters, sizeof(AVFilter*) * (filter_count+1));
 181     filters[filter_count] = filter;
 182     qsort(filters, ++filter_count, sizeof(AVFilter **), filter_cmp);
 183 }
 184
 185 void avfilter_init(void)
 186 {
 187 }
 188
 189 void avfilter_uninit(void)
 190 {
 191     av_freep(&filters);
 192     filter_count = 0;
 193 }
 194
 195 static int pad_count(const AVFilterPad *pads)
 196 {
 197     AVFilterPad *p = (AVFilterPad *) pads;
 198     int count;
 199
 200     for(count = 0; p->name; count ++) p ++;
 201     return count;
 202 }
 203
 204 static const char *filter_name(void *p)
 205 {
 206     AVFilterContext *filter = p;
 207     return filter->filter->name;
 208 }
 209
 210 AVFilterContext *avfilter_create(AVFilter *filter)
 211 {
 212     AVFilterContext *ret = av_malloc(sizeof(AVFilterContext));
 213
 214     ret->av_class = av_mallocz(sizeof(AVClass));
 215     ret->av_class->item_name = filter_name;
 216     ret->filter   = filter;
 217     ret->inputs   = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->inputs));
 218     ret->outputs  = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->outputs));
 219     ret->priv     = av_mallocz(filter->priv_size);
 220
 221     return ret;
 222 }
 223
 224 void avfilter_destroy(AVFilterContext *filter)
 225 {
 226     int i;
 227
 228     if(filter->filter->uninit)
 229         filter->filter->uninit(filter);
 230
 231     for(i = 0; i < pad_count(filter->filter->inputs); i ++) {
 232         if(filter->inputs[i])
 233             filter->inputs[i]->src->outputs[filter->inputs[i]->srcpad] = NULL;
 234         av_free(filter->inputs[i]);
 235     }
 236     for(i = 0; i < pad_count(filter->filter->outputs); i ++) {
 237         if(filter->outputs[i])
 238             filter->outputs[i]->dst->inputs[filter->outputs[i]->dstpad] = NULL;
 239         av_free(filter->outputs[i]);
 240     }
 241
 242     av_free(filter->inputs);
 243     av_free(filter->outputs);
 244     av_free(filter->priv);
 245     av_free(filter->av_class);
 246     av_free(filter);
 247 }
 248
 249 AVFilterContext *avfilter_create_by_name(char *name)
 250 {
 251     AVFilter *filt;
 252
 253     if(!(filt = avfilter_get_by_name(name))) return NULL;
 254     return avfilter_create(filt);
 255 }
 256
 257 int avfilter_init_filter(AVFilterContext *filter)
 258 {
 259     int ret, i;
 260
 261     if(filter->filter->init)
 262         if((ret = filter->filter->init(filter))) return ret;
 263     for(i = 0; i < pad_count(filter->filter->outputs); i ++)
 264         if(filter->outputs[i])
 265             filter->filter->outputs[i].set_video_props(filter->outputs[i]);
 266     return 0;
 267 }
 268