Libav 0.7.1
libavfilter/avfilter.c
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00001 /*
00002  * filter layer
00003  * Copyright (c) 2007 Bobby Bingham
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 /* #define DEBUG */
00023 
00024 #include "libavutil/pixdesc.h"
00025 #include "libavutil/rational.h"
00026 #include "libavutil/audioconvert.h"
00027 #include "libavutil/imgutils.h"
00028 #include "avfilter.h"
00029 #include "internal.h"
00030 
00031 unsigned avfilter_version(void) {
00032     return LIBAVFILTER_VERSION_INT;
00033 }
00034 
00035 const char *avfilter_configuration(void)
00036 {
00037     return LIBAV_CONFIGURATION;
00038 }
00039 
00040 const char *avfilter_license(void)
00041 {
00042 #define LICENSE_PREFIX "libavfilter license: "
00043     return LICENSE_PREFIX LIBAV_LICENSE + sizeof(LICENSE_PREFIX) - 1;
00044 }
00045 
00046 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)
00047 {
00048     AVFilterBufferRef *ret = av_malloc(sizeof(AVFilterBufferRef));
00049     if (!ret)
00050         return NULL;
00051     *ret = *ref;
00052     if (ref->type == AVMEDIA_TYPE_VIDEO) {
00053         ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));
00054         if (!ret->video) {
00055             av_free(ret);
00056             return NULL;
00057         }
00058         *ret->video = *ref->video;
00059     } else if (ref->type == AVMEDIA_TYPE_AUDIO) {
00060         ret->audio = av_malloc(sizeof(AVFilterBufferRefAudioProps));
00061         if (!ret->audio) {
00062             av_free(ret);
00063             return NULL;
00064         }
00065         *ret->audio = *ref->audio;
00066     }
00067     ret->perms &= pmask;
00068     ret->buf->refcount ++;
00069     return ret;
00070 }
00071 
00072 void avfilter_unref_buffer(AVFilterBufferRef *ref)
00073 {
00074     if (!ref)
00075         return;
00076     if (!(--ref->buf->refcount))
00077         ref->buf->free(ref->buf);
00078     av_free(ref->video);
00079     av_free(ref->audio);
00080     av_free(ref);
00081 }
00082 
00083 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
00084                          AVFilterPad **pads, AVFilterLink ***links,
00085                          AVFilterPad *newpad)
00086 {
00087     unsigned i;
00088 
00089     idx = FFMIN(idx, *count);
00090 
00091     *pads  = av_realloc(*pads,  sizeof(AVFilterPad)   * (*count + 1));
00092     *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
00093     memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad)   * (*count-idx));
00094     memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
00095     memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
00096     (*links)[idx] = NULL;
00097 
00098     (*count)++;
00099     for (i = idx+1; i < *count; i++)
00100         if (*links[i])
00101             (*(unsigned *)((uint8_t *) *links[i] + padidx_off))++;
00102 }
00103 
00104 int avfilter_link(AVFilterContext *src, unsigned srcpad,
00105                   AVFilterContext *dst, unsigned dstpad)
00106 {
00107     AVFilterLink *link;
00108 
00109     if (src->output_count <= srcpad || dst->input_count <= dstpad ||
00110         src->outputs[srcpad]        || dst->inputs[dstpad])
00111         return -1;
00112 
00113     if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
00114         av_log(src, AV_LOG_ERROR,
00115                "Media type mismatch between the '%s' filter output pad %d and the '%s' filter input pad %d\n",
00116                src->name, srcpad, dst->name, dstpad);
00117         return AVERROR(EINVAL);
00118     }
00119 
00120     src->outputs[srcpad] =
00121     dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));
00122 
00123     link->src     = src;
00124     link->dst     = dst;
00125     link->srcpad  = &src->output_pads[srcpad];
00126     link->dstpad  = &dst->input_pads[dstpad];
00127     link->type    = src->output_pads[srcpad].type;
00128     assert(PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);
00129     link->format  = -1;
00130 
00131     return 0;
00132 }
00133 
00134 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
00135                            unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
00136 {
00137     int ret;
00138     unsigned dstpad_idx = link->dstpad - link->dst->input_pads;
00139 
00140     av_log(link->dst, AV_LOG_INFO, "auto-inserting filter '%s' "
00141            "between the filter '%s' and the filter '%s'\n",
00142            filt->name, link->src->name, link->dst->name);
00143 
00144     link->dst->inputs[dstpad_idx] = NULL;
00145     if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {
00146         /* failed to link output filter to new filter */
00147         link->dst->inputs[dstpad_idx] = link;
00148         return ret;
00149     }
00150 
00151     /* re-hookup the link to the new destination filter we inserted */
00152     link->dst = filt;
00153     link->dstpad = &filt->input_pads[filt_srcpad_idx];
00154     filt->inputs[filt_srcpad_idx] = link;
00155 
00156     /* if any information on supported media formats already exists on the
00157      * link, we need to preserve that */
00158     if (link->out_formats)
00159         avfilter_formats_changeref(&link->out_formats,
00160                                    &filt->outputs[filt_dstpad_idx]->out_formats);
00161 
00162     return 0;
00163 }
00164 
00165 int avfilter_config_links(AVFilterContext *filter)
00166 {
00167     int (*config_link)(AVFilterLink *);
00168     unsigned i;
00169     int ret;
00170 
00171     for (i = 0; i < filter->input_count; i ++) {
00172         AVFilterLink *link = filter->inputs[i];
00173 
00174         if (!link) continue;
00175 
00176         switch (link->init_state) {
00177         case AVLINK_INIT:
00178             continue;
00179         case AVLINK_STARTINIT:
00180             av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
00181             return 0;
00182         case AVLINK_UNINIT:
00183             link->init_state = AVLINK_STARTINIT;
00184 
00185             if ((ret = avfilter_config_links(link->src)) < 0)
00186                 return ret;
00187 
00188             if (!(config_link = link->srcpad->config_props))
00189                 config_link  = avfilter_default_config_output_link;
00190             if ((ret = config_link(link)) < 0)
00191                 return ret;
00192 
00193             if (link->time_base.num == 0 && link->time_base.den == 0)
00194                 link->time_base = link->src && link->src->input_count ?
00195                     link->src->inputs[0]->time_base : AV_TIME_BASE_Q;
00196 
00197             if (link->sample_aspect_ratio.num == 0 && link->sample_aspect_ratio.den == 0)
00198                 link->sample_aspect_ratio = link->src->input_count ?
00199                     link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
00200 
00201             if (link->sample_rate == 0 && link->src && link->src->input_count)
00202                 link->sample_rate = link->src->inputs[0]->sample_rate;
00203 
00204             if (link->channel_layout == 0 && link->src && link->src->input_count)
00205                 link->channel_layout = link->src->inputs[0]->channel_layout;
00206 
00207             if ((config_link = link->dstpad->config_props))
00208                 if ((ret = config_link(link)) < 0)
00209                     return ret;
00210 
00211             link->init_state = AVLINK_INIT;
00212         }
00213     }
00214 
00215     return 0;
00216 }
00217 
00218 #ifdef DEBUG
00219 static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
00220 {
00221     snprintf(buf, buf_size, "%s%s%s%s%s%s",
00222              perms & AV_PERM_READ      ? "r" : "",
00223              perms & AV_PERM_WRITE     ? "w" : "",
00224              perms & AV_PERM_PRESERVE  ? "p" : "",
00225              perms & AV_PERM_REUSE     ? "u" : "",
00226              perms & AV_PERM_REUSE2    ? "U" : "",
00227              perms & AV_PERM_NEG_LINESIZES ? "n" : "");
00228     return buf;
00229 }
00230 #endif
00231 
00232 static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
00233 {
00234     av_unused char buf[16];
00235     av_dlog(ctx,
00236             "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
00237             ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
00238             ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
00239             ref->pts, ref->pos);
00240 
00241     if (ref->video) {
00242         av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
00243                 ref->video->pixel_aspect.num, ref->video->pixel_aspect.den,
00244                 ref->video->w, ref->video->h,
00245                 !ref->video->interlaced     ? 'P' :         /* Progressive  */
00246                 ref->video->top_field_first ? 'T' : 'B',    /* Top / Bottom */
00247                 ref->video->key_frame,
00248                 av_get_picture_type_char(ref->video->pict_type));
00249     }
00250     if (ref->audio) {
00251         av_dlog(ctx, " cl:%"PRId64"d sn:%d s:%d sr:%d p:%d",
00252                 ref->audio->channel_layout,
00253                 ref->audio->nb_samples,
00254                 ref->audio->size,
00255                 ref->audio->sample_rate,
00256                 ref->audio->planar);
00257     }
00258 
00259     av_dlog(ctx, "]%s", end ? "\n" : "");
00260 }
00261 
00262 static void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
00263 {
00264     if (link->type == AVMEDIA_TYPE_VIDEO) {
00265         av_dlog(ctx,
00266                 "link[%p s:%dx%d fmt:%-16s %-16s->%-16s]%s",
00267                 link, link->w, link->h,
00268                 av_pix_fmt_descriptors[link->format].name,
00269                 link->src ? link->src->filter->name : "",
00270                 link->dst ? link->dst->filter->name : "",
00271                 end ? "\n" : "");
00272     } else {
00273         char buf[128];
00274         av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);
00275 
00276         av_dlog(ctx,
00277                 "link[%p r:%"PRId64" cl:%s fmt:%-16s %-16s->%-16s]%s",
00278                 link, link->sample_rate, buf,
00279                 av_get_sample_fmt_name(link->format),
00280                 link->src ? link->src->filter->name : "",
00281                 link->dst ? link->dst->filter->name : "",
00282                 end ? "\n" : "");
00283     }
00284 }
00285 
00286 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)
00287 
00288 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
00289 {
00290     AVFilterBufferRef *ret = NULL;
00291 
00292     av_unused char buf[16];
00293     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
00294     av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
00295 
00296     if (link->dstpad->get_video_buffer)
00297         ret = link->dstpad->get_video_buffer(link, perms, w, h);
00298 
00299     if (!ret)
00300         ret = avfilter_default_get_video_buffer(link, perms, w, h);
00301 
00302     if (ret)
00303         ret->type = AVMEDIA_TYPE_VIDEO;
00304 
00305     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
00306 
00307     return ret;
00308 }
00309 
00310 AVFilterBufferRef *
00311 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
00312                                           int w, int h, enum PixelFormat format)
00313 {
00314     AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
00315     AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
00316 
00317     if (!pic || !picref)
00318         goto fail;
00319 
00320     picref->buf = pic;
00321     picref->buf->free = ff_avfilter_default_free_buffer;
00322     if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
00323         goto fail;
00324 
00325     pic->w = picref->video->w = w;
00326     pic->h = picref->video->h = h;
00327 
00328     /* make sure the buffer gets read permission or it's useless for output */
00329     picref->perms = perms | AV_PERM_READ;
00330 
00331     pic->refcount = 1;
00332     picref->type = AVMEDIA_TYPE_VIDEO;
00333     pic->format = picref->format = format;
00334 
00335     memcpy(pic->data,        data,          sizeof(pic->data));
00336     memcpy(pic->linesize,    linesize,      sizeof(pic->linesize));
00337     memcpy(picref->data,     pic->data,     sizeof(picref->data));
00338     memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
00339 
00340     return picref;
00341 
00342 fail:
00343     if (picref && picref->video)
00344         av_free(picref->video);
00345     av_free(picref);
00346     av_free(pic);
00347     return NULL;
00348 }
00349 
00350 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
00351                                              enum AVSampleFormat sample_fmt, int size,
00352                                              int64_t channel_layout, int planar)
00353 {
00354     AVFilterBufferRef *ret = NULL;
00355 
00356     if (link->dstpad->get_audio_buffer)
00357         ret = link->dstpad->get_audio_buffer(link, perms, sample_fmt, size, channel_layout, planar);
00358 
00359     if (!ret)
00360         ret = avfilter_default_get_audio_buffer(link, perms, sample_fmt, size, channel_layout, planar);
00361 
00362     if (ret)
00363         ret->type = AVMEDIA_TYPE_AUDIO;
00364 
00365     return ret;
00366 }
00367 
00368 int avfilter_request_frame(AVFilterLink *link)
00369 {
00370     FF_DPRINTF_START(NULL, request_frame); ff_dlog_link(NULL, link, 1);
00371 
00372     if (link->srcpad->request_frame)
00373         return link->srcpad->request_frame(link);
00374     else if (link->src->inputs[0])
00375         return avfilter_request_frame(link->src->inputs[0]);
00376     else return -1;
00377 }
00378 
00379 int avfilter_poll_frame(AVFilterLink *link)
00380 {
00381     int i, min = INT_MAX;
00382 
00383     if (link->srcpad->poll_frame)
00384         return link->srcpad->poll_frame(link);
00385 
00386     for (i = 0; i < link->src->input_count; i++) {
00387         int val;
00388         if (!link->src->inputs[i])
00389             return -1;
00390         val = avfilter_poll_frame(link->src->inputs[i]);
00391         min = FFMIN(min, val);
00392     }
00393 
00394     return min;
00395 }
00396 
00397 /* XXX: should we do the duplicating of the picture ref here, instead of
00398  * forcing the source filter to do it? */
00399 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
00400 {
00401     void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);
00402     AVFilterPad *dst = link->dstpad;
00403     int perms = picref->perms;
00404 
00405     FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);
00406 
00407     if (!(start_frame = dst->start_frame))
00408         start_frame = avfilter_default_start_frame;
00409 
00410     if (picref->linesize[0] < 0)
00411         perms |= AV_PERM_NEG_LINESIZES;
00412     /* prepare to copy the picture if it has insufficient permissions */
00413     if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {
00414         av_log(link->dst, AV_LOG_DEBUG,
00415                 "frame copy needed (have perms %x, need %x, reject %x)\n",
00416                 picref->perms,
00417                 link->dstpad->min_perms, link->dstpad->rej_perms);
00418 
00419         link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);
00420         link->src_buf = picref;
00421         avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);
00422     }
00423     else
00424         link->cur_buf = picref;
00425 
00426     start_frame(link, link->cur_buf);
00427 }
00428 
00429 void avfilter_end_frame(AVFilterLink *link)
00430 {
00431     void (*end_frame)(AVFilterLink *);
00432 
00433     if (!(end_frame = link->dstpad->end_frame))
00434         end_frame = avfilter_default_end_frame;
00435 
00436     end_frame(link);
00437 
00438     /* unreference the source picture if we're feeding the destination filter
00439      * a copied version dues to permission issues */
00440     if (link->src_buf) {
00441         avfilter_unref_buffer(link->src_buf);
00442         link->src_buf = NULL;
00443     }
00444 }
00445 
00446 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
00447 {
00448     uint8_t *src[4], *dst[4];
00449     int i, j, vsub;
00450     void (*draw_slice)(AVFilterLink *, int, int, int);
00451 
00452     FF_DPRINTF_START(NULL, draw_slice); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " y:%d h:%d dir:%d\n", y, h, slice_dir);
00453 
00454     /* copy the slice if needed for permission reasons */
00455     if (link->src_buf) {
00456         vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
00457 
00458         for (i = 0; i < 4; i++) {
00459             if (link->src_buf->data[i]) {
00460                 src[i] = link->src_buf-> data[i] +
00461                     (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];
00462                 dst[i] = link->cur_buf->data[i] +
00463                     (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];
00464             } else
00465                 src[i] = dst[i] = NULL;
00466         }
00467 
00468         for (i = 0; i < 4; i++) {
00469             int planew =
00470                 av_image_get_linesize(link->format, link->cur_buf->video->w, i);
00471 
00472             if (!src[i]) continue;
00473 
00474             for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {
00475                 memcpy(dst[i], src[i], planew);
00476                 src[i] += link->src_buf->linesize[i];
00477                 dst[i] += link->cur_buf->linesize[i];
00478             }
00479         }
00480     }
00481 
00482     if (!(draw_slice = link->dstpad->draw_slice))
00483         draw_slice = avfilter_default_draw_slice;
00484     draw_slice(link, y, h, slice_dir);
00485 }
00486 
00487 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref)
00488 {
00489     void (*filter_samples)(AVFilterLink *, AVFilterBufferRef *);
00490     AVFilterPad *dst = link->dstpad;
00491 
00492     FF_DPRINTF_START(NULL, filter_samples); ff_dlog_link(NULL, link, 1);
00493 
00494     if (!(filter_samples = dst->filter_samples))
00495         filter_samples = avfilter_default_filter_samples;
00496 
00497     /* prepare to copy the samples if the buffer has insufficient permissions */
00498     if ((dst->min_perms & samplesref->perms) != dst->min_perms ||
00499         dst->rej_perms & samplesref->perms) {
00500 
00501         av_log(link->dst, AV_LOG_DEBUG,
00502                "Copying audio data in avfilter (have perms %x, need %x, reject %x)\n",
00503                samplesref->perms, link->dstpad->min_perms, link->dstpad->rej_perms);
00504 
00505         link->cur_buf = avfilter_default_get_audio_buffer(link, dst->min_perms,
00506                                                           samplesref->format,
00507                                                           samplesref->audio->size,
00508                                                           samplesref->audio->channel_layout,
00509                                                           samplesref->audio->planar);
00510         link->cur_buf->pts                = samplesref->pts;
00511         link->cur_buf->audio->sample_rate = samplesref->audio->sample_rate;
00512 
00513         /* Copy actual data into new samples buffer */
00514         memcpy(link->cur_buf->data[0], samplesref->data[0], samplesref->audio->size);
00515 
00516         avfilter_unref_buffer(samplesref);
00517     } else
00518         link->cur_buf = samplesref;
00519 
00520     filter_samples(link, link->cur_buf);
00521 }
00522 
00523 #define MAX_REGISTERED_AVFILTERS_NB 64
00524 
00525 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
00526 
00527 static int next_registered_avfilter_idx = 0;
00528 
00529 AVFilter *avfilter_get_by_name(const char *name)
00530 {
00531     int i;
00532 
00533     for (i = 0; registered_avfilters[i]; i++)
00534         if (!strcmp(registered_avfilters[i]->name, name))
00535             return registered_avfilters[i];
00536 
00537     return NULL;
00538 }
00539 
00540 int avfilter_register(AVFilter *filter)
00541 {
00542     if (next_registered_avfilter_idx == MAX_REGISTERED_AVFILTERS_NB)
00543         return -1;
00544 
00545     registered_avfilters[next_registered_avfilter_idx++] = filter;
00546     return 0;
00547 }
00548 
00549 AVFilter **av_filter_next(AVFilter **filter)
00550 {
00551     return filter ? ++filter : &registered_avfilters[0];
00552 }
00553 
00554 void avfilter_uninit(void)
00555 {
00556     memset(registered_avfilters, 0, sizeof(registered_avfilters));
00557     next_registered_avfilter_idx = 0;
00558 }
00559 
00560 static int pad_count(const AVFilterPad *pads)
00561 {
00562     int count;
00563 
00564     for(count = 0; pads->name; count ++) pads ++;
00565     return count;
00566 }
00567 
00568 static const char *filter_name(void *p)
00569 {
00570     AVFilterContext *filter = p;
00571     return filter->filter->name;
00572 }
00573 
00574 static const AVClass avfilter_class = {
00575     "AVFilter",
00576     filter_name,
00577     NULL,
00578     LIBAVUTIL_VERSION_INT,
00579 };
00580 
00581 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name)
00582 {
00583     AVFilterContext *ret;
00584     *filter_ctx = NULL;
00585 
00586     if (!filter)
00587         return AVERROR(EINVAL);
00588 
00589     ret = av_mallocz(sizeof(AVFilterContext));
00590     if (!ret)
00591         return AVERROR(ENOMEM);
00592 
00593     ret->av_class = &avfilter_class;
00594     ret->filter   = filter;
00595     ret->name     = inst_name ? av_strdup(inst_name) : NULL;
00596     if (filter->priv_size) {
00597         ret->priv     = av_mallocz(filter->priv_size);
00598         if (!ret->priv)
00599             goto err;
00600     }
00601 
00602     ret->input_count  = pad_count(filter->inputs);
00603     if (ret->input_count) {
00604         ret->input_pads   = av_malloc(sizeof(AVFilterPad) * ret->input_count);
00605         if (!ret->input_pads)
00606             goto err;
00607         memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->input_count);
00608         ret->inputs       = av_mallocz(sizeof(AVFilterLink*) * ret->input_count);
00609         if (!ret->inputs)
00610             goto err;
00611     }
00612 
00613     ret->output_count = pad_count(filter->outputs);
00614     if (ret->output_count) {
00615         ret->output_pads  = av_malloc(sizeof(AVFilterPad) * ret->output_count);
00616         if (!ret->output_pads)
00617             goto err;
00618         memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->output_count);
00619         ret->outputs      = av_mallocz(sizeof(AVFilterLink*) * ret->output_count);
00620         if (!ret->outputs)
00621             goto err;
00622     }
00623 
00624     *filter_ctx = ret;
00625     return 0;
00626 
00627 err:
00628     av_freep(&ret->inputs);
00629     av_freep(&ret->input_pads);
00630     ret->input_count = 0;
00631     av_freep(&ret->outputs);
00632     av_freep(&ret->output_pads);
00633     ret->output_count = 0;
00634     av_freep(&ret->priv);
00635     av_free(ret);
00636     return AVERROR(ENOMEM);
00637 }
00638 
00639 void avfilter_free(AVFilterContext *filter)
00640 {
00641     int i;
00642     AVFilterLink *link;
00643 
00644     if (filter->filter->uninit)
00645         filter->filter->uninit(filter);
00646 
00647     for (i = 0; i < filter->input_count; i++) {
00648         if ((link = filter->inputs[i])) {
00649             if (link->src)
00650                 link->src->outputs[link->srcpad - link->src->output_pads] = NULL;
00651             avfilter_formats_unref(&link->in_formats);
00652             avfilter_formats_unref(&link->out_formats);
00653         }
00654         av_freep(&link);
00655     }
00656     for (i = 0; i < filter->output_count; i++) {
00657         if ((link = filter->outputs[i])) {
00658             if (link->dst)
00659                 link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;
00660             avfilter_formats_unref(&link->in_formats);
00661             avfilter_formats_unref(&link->out_formats);
00662         }
00663         av_freep(&link);
00664     }
00665 
00666     av_freep(&filter->name);
00667     av_freep(&filter->input_pads);
00668     av_freep(&filter->output_pads);
00669     av_freep(&filter->inputs);
00670     av_freep(&filter->outputs);
00671     av_freep(&filter->priv);
00672     av_free(filter);
00673 }
00674 
00675 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
00676 {
00677     int ret=0;
00678 
00679     if (filter->filter->init)
00680         ret = filter->filter->init(filter, args, opaque);
00681     return ret;
00682 }
00683