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libavfilter/avfilter.c

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00001 /*
00002  * filter layer
00003  * copyright (c) 2007 Bobby Bingham
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavcodec/imgconvert.h"
00023 #include "avfilter.h"
00024 
00025 unsigned avfilter_version(void) {
00026     return LIBAVFILTER_VERSION_INT;
00027 }
00028 
00030 struct FilterList
00031 {
00032     AVFilter *filter;
00033     struct FilterList *next;
00034 } *filters = NULL;
00035 
00037 #define link_dpad(link)     link->dst-> input_pads[link->dstpad]
00038 #define link_spad(link)     link->src->output_pads[link->srcpad]
00039 
00040 AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask)
00041 {
00042     AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
00043     *ret = *ref;
00044     ret->perms &= pmask;
00045     ret->pic->refcount ++;
00046     return ret;
00047 }
00048 
00049 void avfilter_unref_pic(AVFilterPicRef *ref)
00050 {
00051     if(!(--ref->pic->refcount))
00052         ref->pic->free(ref->pic);
00053     av_free(ref);
00054 }
00055 
00056 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
00057                          AVFilterPad **pads, AVFilterLink ***links,
00058                          AVFilterPad *newpad)
00059 {
00060     unsigned i;
00061 
00062     idx = FFMIN(idx, *count);
00063 
00064     *pads  = av_realloc(*pads,  sizeof(AVFilterPad)   * (*count + 1));
00065     *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
00066     memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad)   * (*count-idx));
00067     memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
00068     memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
00069     (*links)[idx] = NULL;
00070 
00071     (*count) ++;
00072     for(i = idx+1; i < *count; i ++)
00073         if(*links[i])
00074             (*(unsigned *)((uint8_t *) *links[i] + padidx_off)) ++;
00075 }
00076 
00077 int avfilter_link(AVFilterContext *src, unsigned srcpad,
00078                   AVFilterContext *dst, unsigned dstpad)
00079 {
00080     AVFilterLink *link;
00081 
00082     if(src->output_count <= srcpad || dst->input_count <= dstpad ||
00083        src->outputs[srcpad]        || dst->inputs[dstpad])
00084         return -1;
00085 
00086     src->outputs[srcpad] =
00087     dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));
00088 
00089     link->src     = src;
00090     link->dst     = dst;
00091     link->srcpad  = srcpad;
00092     link->dstpad  = dstpad;
00093     link->format  = PIX_FMT_NONE;
00094 
00095     return 0;
00096 }
00097 
00098 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
00099                            unsigned in, unsigned out)
00100 {
00101     av_log(link->dst, AV_LOG_INFO, "auto-inserting filter '%s'\n",
00102             filt->filter->name);
00103 
00104     link->dst->inputs[link->dstpad] = NULL;
00105     if(avfilter_link(filt, out, link->dst, link->dstpad)) {
00106         /* failed to link output filter to new filter */
00107         link->dst->inputs[link->dstpad] = link;
00108         return -1;
00109     }
00110 
00111     /* re-hookup the link to the new destination filter we inserted */
00112     link->dst = filt;
00113     link->dstpad = in;
00114     filt->inputs[in] = link;
00115 
00116     /* if any information on supported colorspaces already exists on the
00117      * link, we need to preserve that */
00118     if(link->out_formats)
00119         avfilter_formats_changeref(&link->out_formats,
00120                                    &filt->outputs[out]->out_formats);
00121 
00122     return 0;
00123 }
00124 
00125 int avfilter_config_links(AVFilterContext *filter)
00126 {
00127     int (*config_link)(AVFilterLink *);
00128     unsigned i;
00129 
00130     for(i = 0; i < filter->input_count; i ++) {
00131         AVFilterLink *link = filter->inputs[i];
00132 
00133         if(!link) continue;
00134 
00135         switch(link->init_state) {
00136         case AVLINK_INIT:
00137             continue;
00138         case AVLINK_STARTINIT:
00139             av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
00140             return 0;
00141         case AVLINK_UNINIT:
00142             link->init_state = AVLINK_STARTINIT;
00143 
00144             if(avfilter_config_links(link->src))
00145                 return -1;
00146 
00147             if(!(config_link = link_spad(link).config_props))
00148                 config_link  = avfilter_default_config_output_link;
00149             if(config_link(link))
00150                 return -1;
00151 
00152             if((config_link = link_dpad(link).config_props))
00153                 if(config_link(link))
00154                     return -1;
00155 
00156             link->init_state = AVLINK_INIT;
00157         }
00158     }
00159 
00160     return 0;
00161 }
00162 
00163 AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms)
00164 {
00165     AVFilterPicRef *ret = NULL;
00166 
00167     if(link_dpad(link).get_video_buffer)
00168         ret = link_dpad(link).get_video_buffer(link, perms);
00169 
00170     if(!ret)
00171         ret = avfilter_default_get_video_buffer(link, perms);
00172 
00173     return ret;
00174 }
00175 
00176 int avfilter_request_frame(AVFilterLink *link)
00177 {
00178     if(link_spad(link).request_frame)
00179         return link_spad(link).request_frame(link);
00180     else if(link->src->inputs[0])
00181         return avfilter_request_frame(link->src->inputs[0]);
00182     else return -1;
00183 }
00184 
00185 int avfilter_poll_frame(AVFilterLink *link)
00186 {
00187     int i, min=INT_MAX;
00188 
00189     if(link_spad(link).poll_frame)
00190         return link_spad(link).poll_frame(link);
00191 
00192     for (i=0; i<link->src->input_count; i++) {
00193         if(!link->src->inputs[i])
00194             return -1;
00195         min = FFMIN(min, avfilter_poll_frame(link->src->inputs[i]));
00196     }
00197 
00198     return min;
00199 }
00200 
00201 /* XXX: should we do the duplicating of the picture ref here, instead of
00202  * forcing the source filter to do it? */
00203 void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
00204 {
00205     void (*start_frame)(AVFilterLink *, AVFilterPicRef *);
00206     AVFilterPad *dst = &link_dpad(link);
00207 
00208     if(!(start_frame = dst->start_frame))
00209         start_frame = avfilter_default_start_frame;
00210 
00211     /* prepare to copy the picture if it has insufficient permissions */
00212     if((dst->min_perms & picref->perms) != dst->min_perms ||
00213         dst->rej_perms & picref->perms) {
00214         /*
00215         av_log(link->dst, AV_LOG_INFO,
00216                 "frame copy needed (have perms %x, need %x, reject %x)\n",
00217                 picref->perms,
00218                 link_dpad(link).min_perms, link_dpad(link).rej_perms);
00219         */
00220 
00221         link->cur_pic = avfilter_default_get_video_buffer(link, dst->min_perms);
00222         link->srcpic = picref;
00223         link->cur_pic->pts = link->srcpic->pts;
00224     }
00225     else
00226         link->cur_pic = picref;
00227 
00228     start_frame(link, link->cur_pic);
00229 }
00230 
00231 void avfilter_end_frame(AVFilterLink *link)
00232 {
00233     void (*end_frame)(AVFilterLink *);
00234 
00235     if(!(end_frame = link_dpad(link).end_frame))
00236         end_frame = avfilter_default_end_frame;
00237 
00238     end_frame(link);
00239 
00240     /* unreference the source picture if we're feeding the destination filter
00241      * a copied version dues to permission issues */
00242     if(link->srcpic) {
00243         avfilter_unref_pic(link->srcpic);
00244         link->srcpic = NULL;
00245     }
00246 
00247 }
00248 
00249 void avfilter_draw_slice(AVFilterLink *link, int y, int h)
00250 {
00251     uint8_t *src[4], *dst[4];
00252     int i, j, hsub, vsub;
00253     void (*draw_slice)(AVFilterLink *, int, int);
00254 
00255     /* copy the slice if needed for permission reasons */
00256     if(link->srcpic) {
00257         avcodec_get_chroma_sub_sample(link->format, &hsub, &vsub);
00258 
00259         for(i = 0; i < 4; i ++) {
00260             if(link->srcpic->data[i]) {
00261                 src[i] = link->srcpic-> data[i] +
00262                     (y >> (i==0 ? 0 : vsub)) * link->srcpic-> linesize[i];
00263                 dst[i] = link->cur_pic->data[i] +
00264                     (y >> (i==0 ? 0 : vsub)) * link->cur_pic->linesize[i];
00265             } else
00266                 src[i] = dst[i] = NULL;
00267         }
00268 
00269         for(i = 0; i < 4; i ++) {
00270             int planew =
00271                 ff_get_plane_bytewidth(link->format, link->cur_pic->w, i);
00272 
00273             if(!src[i]) continue;
00274 
00275             for(j = 0; j < h >> (i==0 ? 0 : vsub); j ++) {
00276                 memcpy(dst[i], src[i], planew);
00277                 src[i] += link->srcpic ->linesize[i];
00278                 dst[i] += link->cur_pic->linesize[i];
00279             }
00280         }
00281     }
00282 
00283     if(!(draw_slice = link_dpad(link).draw_slice))
00284         draw_slice = avfilter_default_draw_slice;
00285     draw_slice(link, y, h);
00286 }
00287 
00288 AVFilter *avfilter_get_by_name(const char *name)
00289 {
00290     struct FilterList *filt;
00291 
00292     for(filt = filters; filt; filt = filt->next)
00293         if(!strcmp(filt->filter->name, name))
00294             return filt->filter;
00295 
00296     return NULL;
00297 }
00298 
00299 void avfilter_register(AVFilter *filter)
00300 {
00301     struct FilterList *newfilt = av_malloc(sizeof(struct FilterList));
00302 
00303     newfilt->filter = filter;
00304     newfilt->next   = filters;
00305     filters         = newfilt;
00306 }
00307 
00308 void avfilter_uninit(void)
00309 {
00310     struct FilterList *tmp;
00311 
00312     for(; filters; filters = tmp) {
00313         tmp = filters->next;
00314         av_free(filters);
00315     }
00316 }
00317 
00318 static int pad_count(const AVFilterPad *pads)
00319 {
00320     int count;
00321 
00322     for(count = 0; pads->name; count ++) pads ++;
00323     return count;
00324 }
00325 
00326 static const char *filter_name(void *p)
00327 {
00328     AVFilterContext *filter = p;
00329     return filter->filter->name;
00330 }
00331 
00332 static const AVClass avfilter_class = {
00333     "AVFilter",
00334     filter_name
00335 };
00336 
00337 AVFilterContext *avfilter_open(AVFilter *filter, const char *inst_name)
00338 {
00339     AVFilterContext *ret;
00340 
00341     if (!filter)
00342         return 0;
00343 
00344     ret = av_mallocz(sizeof(AVFilterContext));
00345 
00346     ret->av_class = &avfilter_class;
00347     ret->filter   = filter;
00348     ret->name     = inst_name ? av_strdup(inst_name) : NULL;
00349     ret->priv     = av_mallocz(filter->priv_size);
00350 
00351     ret->input_count  = pad_count(filter->inputs);
00352     if (ret->input_count) {
00353         ret->input_pads   = av_malloc(sizeof(AVFilterPad) * ret->input_count);
00354         memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->input_count);
00355         ret->inputs       = av_mallocz(sizeof(AVFilterLink*) * ret->input_count);
00356     }
00357 
00358     ret->output_count = pad_count(filter->outputs);
00359     if (ret->output_count) {
00360         ret->output_pads  = av_malloc(sizeof(AVFilterPad) * ret->output_count);
00361         memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->output_count);
00362         ret->outputs      = av_mallocz(sizeof(AVFilterLink*) * ret->output_count);
00363     }
00364 
00365     return ret;
00366 }
00367 
00368 void avfilter_destroy(AVFilterContext *filter)
00369 {
00370     int i;
00371 
00372     if(filter->filter->uninit)
00373         filter->filter->uninit(filter);
00374 
00375     for(i = 0; i < filter->input_count; i ++) {
00376         if(filter->inputs[i])
00377             filter->inputs[i]->src->outputs[filter->inputs[i]->srcpad] = NULL;
00378         av_freep(&filter->inputs[i]);
00379     }
00380     for(i = 0; i < filter->output_count; i ++) {
00381         if(filter->outputs[i])
00382             filter->outputs[i]->dst->inputs[filter->outputs[i]->dstpad] = NULL;
00383         av_freep(&filter->outputs[i]);
00384     }
00385 
00386     av_freep(&filter->name);
00387     av_freep(&filter->input_pads);
00388     av_freep(&filter->output_pads);
00389     av_freep(&filter->inputs);
00390     av_freep(&filter->outputs);
00391     av_freep(&filter->priv);
00392     av_free(filter);
00393 }
00394 
00395 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
00396 {
00397     int ret=0;
00398 
00399     if(filter->filter->init)
00400         ret = filter->filter->init(filter, args, opaque);
00401     return ret;
00402 }
00403 

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