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 #include "allfilters.h"
  28
  29 /** list of registered filters, sorted by name */
  30 static int filter_count = 0;
  31 static AVFilter **filters = NULL;
  32
  33 /* TODO: buffer pool.  see comment for avfilter_default_get_video_buffer() */
  34 void avfilter_default_free_video_buffer(AVFilterPic *pic)
  35 {
  36     avpicture_free((AVPicture *) pic);
  37     av_free(pic);
  38 }
  39
  40 /* TODO: set the buffer's priv member to a context structure for the whole
  41  * filter chain.  This will allow for a buffer pool instead of the constant
  42  * alloc & free cycle currently implemented. */
  43 AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms)
  44 {
  45     AVFilterPic *pic = av_mallocz(sizeof(AVFilterPic));
  46     AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
  47
  48     ref->pic = pic;
  49     ref->w = link->w;
  50     ref->h = link->h;
  51     ref->perms = perms;
  52
  53     pic->refcount = 1;
  54     pic->format = link->format;
  55     pic->free = avfilter_default_free_video_buffer;
  56     avpicture_alloc((AVPicture *)pic, pic->format, ref->w, ref->h);
  57
  58     memcpy(ref->data, pic->data, sizeof(uint8_t *) * 4);
  59     memcpy(ref->linesize, pic->linesize, sizeof(int *) * 4);
  60
  61     return ref;
  62 }
  63
  64 void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
  65 {
  66     link->cur_pic = picref;
  67 }
  68
  69 void avfilter_default_end_frame(AVFilterLink *link)
  70 {
  71     avfilter_unref_pic(link->cur_pic);
  72     link->cur_pic = NULL;
  73 }
  74
  75 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref)
  76 {
  77     AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
  78     memcpy(ret, ref, sizeof(AVFilterPicRef));
  79     ret->pic->refcount ++;
  80     return ret;
  81 }
  82
  83 void avfilter_unref_pic(AVFilterPicRef *ref)
  84 {
  85     if(-- ref->pic->refcount == 0)
  86         ref->pic->free(ref->pic);
  87     av_free(ref);
  88 }
  89
  90 int avfilter_link(AVFilterContext *src, unsigned srcpad,
  91                   AVFilterContext *dst, unsigned dstpad)
  92 {
  93     AVFilterLink *link;
  94
  95     if(src->outputs[srcpad] || dst->inputs[dstpad])
  96         return -1;
  97
  98     src->outputs[srcpad] =
  99     dst->inputs[dstpad]  = link = av_malloc(sizeof(AVFilterLink));
 100
 101     link->src = src;
 102     link->dst = dst;
 103     link->srcpad = srcpad;
 104     link->dstpad = dstpad;
 105     link->cur_pic = NULL;
 106
 107     src->filter->outputs[dstpad].set_video_props(link);
 108     return 0;
 109 }
 110
 111 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms)
 112 {
 113     AVFilterPicRef *ret = NULL;
 114
 115     if(link->dst->filter->inputs[link->dstpad].get_video_buffer)
 116         ret = link->dst->filter->inputs[link->dstpad].get_video_buffer(link, perms);
 117
 118     if(!ret)
 119         ret = avfilter_default_get_video_buffer(link, perms);
 120
 121     return ret;
 122 }
 123
 124 void avfilter_request_frame(AVFilterLink *link)
 125 {
 126     link->src->filter->outputs[link->srcpad].request_frame(link);
 127 }
 128
 129 /* XXX: should we do the duplicating of the picture ref here, instead of
 130  * forcing the source filter to do it? */
 131 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
 132 {
 133     void (*start_frame)(AVFilterLink *, AVFilterPicRef *);
 134
 135     start_frame = link->dst->filter->inputs[link->dstpad].start_frame;
 136     if(!start_frame)
 137         start_frame = avfilter_default_start_frame;
 138
 139     start_frame(link, picref);
 140 }
 141
 142 void avfilter_end_frame(AVFilterLink *link)
 143 {
 144     void (*end_frame)(AVFilterLink *);
 145
 146     end_frame = link->dst->filter->inputs[link->dstpad].end_frame;
 147     if(!end_frame)
 148         end_frame = avfilter_default_end_frame;
 149
 150     end_frame(link);
 151 }
 152
 153 void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h)
 154 {
 155     link->dst->filter->inputs[link->dstpad].draw_slice(link, data, y, h);
 156 }
 157
 158 static int filter_cmp(const void *aa, const void *bb)
 159 {
 160     const AVFilter *a = *(const AVFilter **)aa, *b = *(const AVFilter **)bb;
 161     return strcmp(a->name, b->name);
 162 }
 163
 164 AVFilter *avfilter_get_by_name(char *name)
 165 {
 166     AVFilter key = { .name = name, };
 167     AVFilter *key2 = &key;
 168     AVFilter **ret;
 169
 170     ret = bsearch(&key2, filters, filter_count, sizeof(AVFilter **), filter_cmp);
 171     if(ret)
 172         return *ret;
 173     return NULL;
 174 }
 175
 176 /* FIXME: insert in order, rather than insert at end + resort */
 177 void avfilter_register(AVFilter *filter)
 178 {
 179     filters = av_realloc(filters, sizeof(AVFilter*) * (filter_count+1));
 180     filters[filter_count] = filter;
 181     qsort(filters, ++filter_count, sizeof(AVFilter **), filter_cmp);
 182 }
 183
 184 void avfilter_init(void)
 185 {
 186     avfilter_register(&vsrc_dummy);
 187     avfilter_register(&vf_crop);
 188     avfilter_register(&vf_passthrough);
 189     avfilter_register(&vo_sdl);
 190 }
 191
 192 void avfilter_uninit(void)
 193 {
 194     av_freep(&filters);
 195     filter_count = 0;
 196 }
 197
 198 static int pad_count(const AVFilterPad *pads)
 199 {
 200     AVFilterPad *p = (AVFilterPad *) pads;
 201     int count;
 202
 203     for(count = 0; p->name; count ++) p ++;
 204     return count;
 205 }
 206
 207 static const char *filter_name(void *p)
 208 {
 209     AVFilterContext *filter = p;
 210     return filter->filter->name;
 211 }
 212
 213 AVFilterContext *avfilter_create(AVFilter *filter)
 214 {
 215     AVFilterContext *ret = av_malloc(sizeof(AVFilterContext));
 216
 217     ret->av_class = av_mallocz(sizeof(AVClass));
 218     ret->av_class->item_name = filter_name;
 219     ret->filter   = filter;
 220     ret->inputs   = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->inputs));
 221     ret->outputs  = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->outputs));
 222     ret->priv     = av_mallocz(filter->priv_size);
 223
 224     return ret;
 225 }
 226
 227 void avfilter_destroy(AVFilterContext *filter)
 228 {
 229     int i;
 230
 231     if(filter->filter->uninit)
 232         filter->filter->uninit(filter);
 233
 234     for(i = 0; i < pad_count(filter->filter->inputs); i ++) {
 235         if(filter->inputs[i])
 236             filter->inputs[i]->src->outputs[filter->inputs[i]->srcpad] = NULL;
 237         av_free(filter->inputs[i]);
 238     }
 239     for(i = 0; i < pad_count(filter->filter->outputs); i ++) {
 240         if(filter->outputs[i])
 241             filter->outputs[i]->dst->inputs[filter->outputs[i]->dstpad] = NULL;
 242         av_free(filter->outputs[i]);
 243     }
 244
 245     av_free(filter->inputs);
 246     av_free(filter->outputs);
 247     av_free(filter->priv);
 248     av_free(filter->av_class);
 249     av_free(filter);
 250 }
 251
 252 AVFilterContext *avfilter_create_by_name(char *name)
 253 {
 254     AVFilter *filt;
 255
 256     if(!(filt = avfilter_get_by_name(name))) return NULL;
 257     return avfilter_create(filt);
 258 }
 259
 260 int avfilter_init_filter(AVFilterContext *filter)
 261 {
 262     int ret, i;
 263
 264     if(filter->filter->init)
 265         if((ret = filter->filter->init(filter))) return ret;
 266     for(i = 0; i < pad_count(filter->filter->outputs); i ++)
 267         if(filter->outputs[i])
 268             filter->filter->outputs[i].set_video_props(filter->outputs[i]);
 269     return 0;
 270 }
 271