/*

  * filter layer

  * Copyright (c) 2007 Bobby Bingham

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 /* #define DEBUG */
 

 #include "libavutil/pixdesc.h"

 #include "libavutil/rational.h"

 #include "libavutil/audioconvert.h"
 #include "libavutil/imgutils.h"

 #include "libavutil/avassert.h"

 #include "avfilter.h"

 #include "internal.h"

 unsigned avfilter_version(void) {
     return LIBAVFILTER_VERSION_INT;
 }
 

 const char *avfilter_configuration(void)

 {

     return FFMPEG_CONFIGURATION;

 }
 

 const char *avfilter_license(void)

 {
 #define LICENSE_PREFIX "libavfilter license: "

     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;

 }
 

 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)

 {

     AVFilterBufferRef *ret = av_malloc(sizeof(AVFilterBufferRef));

     if (!ret)
         return NULL;

     *ret = *ref;

     if (ref->type == AVMEDIA_TYPE_VIDEO) {
         ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));

         if (!ret->video) {
             av_free(ret);
             return NULL;
         }

         *ret->video = *ref->video;

     } else if (ref->type == AVMEDIA_TYPE_AUDIO) {
         ret->audio = av_malloc(sizeof(AVFilterBufferRefAudioProps));
         if (!ret->audio) {
             av_free(ret);
             return NULL;
         }
         *ret->audio = *ref->audio;

     }

     ret->perms &= pmask;

     ret->buf->refcount ++;

     return ret;
 }
 

 static void store_in_pool(AVFilterBufferRef *ref)
 {
     int i;

     AVFilterPool *pool= ref->buf->priv;

 
     av_assert0(ref->buf->data[0]);
 

     if (pool->count == POOL_SIZE) {
         AVFilterBufferRef *ref1 = pool->pic[0];

         av_freep(&ref1->video);
         av_freep(&ref1->audio);
         av_freep(&ref1->buf->data[0]);
         av_freep(&ref1->buf);
         av_free(ref1);
         memmove(&pool->pic[0], &pool->pic[1], sizeof(void*)*(POOL_SIZE-1));
         pool->count--;
         pool->pic[POOL_SIZE-1] = NULL;
     }
 

     for (i = 0; i < POOL_SIZE; i++) {
         if (!pool->pic[i]) {
             pool->pic[i] = ref;

             pool->count++;
             break;
         }
     }
 }
 

 void avfilter_unref_buffer(AVFilterBufferRef *ref)

 {

     if (!ref)
         return;

     if (!(--ref->buf->refcount)) {
         if (!ref->buf->free) {

             store_in_pool(ref);
             return;
         }

         ref->buf->free(ref->buf);

     }

     av_freep(&ref->video);
     av_freep(&ref->audio);

     av_free(ref);
 }
 

 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
                          AVFilterPad **pads, AVFilterLink ***links,
                          AVFilterPad *newpad)
 {
     unsigned i;
 
     idx = FFMIN(idx, *count);
 
     *pads  = av_realloc(*pads,  sizeof(AVFilterPad)   * (*count + 1));
     *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
     memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad)   * (*count-idx));
     memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
     memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
     (*links)[idx] = NULL;
 

     (*count)++;
     for (i = idx+1; i < *count; i++)
         if (*links[i])
             (*(unsigned *)((uint8_t *) *links[i] + padidx_off))++;

 }
 

 int avfilter_link(AVFilterContext *src, unsigned srcpad,
                   AVFilterContext *dst, unsigned dstpad)
 {
     AVFilterLink *link;
 

     if (src->output_count <= srcpad || dst->input_count <= dstpad ||
         src->outputs[srcpad]        || dst->inputs[dstpad])

         return -1;
 

     if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
         av_log(src, AV_LOG_ERROR,
                "Media type mismatch between the '%s' filter output pad %d and the '%s' filter input pad %d\n",
                src->name, srcpad, dst->name, dstpad);
         return AVERROR(EINVAL);
     }
 

     src->outputs[srcpad] =

     dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));

     link->src     = src;
     link->dst     = dst;

     link->srcpad  = &src->output_pads[srcpad];
     link->dstpad  = &dst->input_pads[dstpad];

     link->type    = src->output_pads[srcpad].type;

     assert(PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);

     link->format  = -1;

 
     return 0;
 }
 

 void avfilter_link_free(AVFilterLink **link)
 {
     if (!*link)
         return;
 
     if ((*link)->pool) {
         int i;
         for (i = 0; i < POOL_SIZE; i++) {
             if ((*link)->pool->pic[i]) {
                 AVFilterBufferRef *picref = (*link)->pool->pic[i];
                 /* free buffer: picrefs stored in the pool are not
                  * supposed to contain a free callback */
                 av_freep(&picref->buf->data[0]);
                 av_freep(&picref->buf);
 
                 av_freep(&picref->audio);
                 av_freep(&picref->video);

                 av_freep(&(*link)->pool->pic[i]);

             }
         }

         (*link)->pool->count = 0;
 //        av_freep(&(*link)->pool);

     }
     av_freep(link);
 }
 

 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,

                            unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)

 {

     int ret;

     unsigned dstpad_idx = link->dstpad - link->dst->input_pads;
 

     av_log(link->dst, AV_LOG_INFO, "auto-inserting filter '%s' "
            "between the filter '%s' and the filter '%s'\n",
            filt->name, link->src->name, link->dst->name);

     link->dst->inputs[dstpad_idx] = NULL;

     if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {

         /* failed to link output filter to new filter */

         link->dst->inputs[dstpad_idx] = link;

         return ret;

     }
 
     /* re-hookup the link to the new destination filter we inserted */
     link->dst = filt;

     link->dstpad = &filt->input_pads[filt_srcpad_idx];
     filt->inputs[filt_srcpad_idx] = link;

     /* if any information on supported media formats already exists on the

      * link, we need to preserve that */

     if (link->out_formats)

         avfilter_formats_changeref(&link->out_formats,

                                    &filt->outputs[filt_dstpad_idx]->out_formats);

     if (link->out_chlayouts)
         avfilter_formats_changeref(&link->out_chlayouts,
                                    &filt->outputs[filt_dstpad_idx]->out_chlayouts);

     return 0;
 }
 

 int avfilter_config_links(AVFilterContext *filter)

 {
     int (*config_link)(AVFilterLink *);

     unsigned i;

     int ret;

     for (i = 0; i < filter->input_count; i ++) {

         AVFilterLink *link = filter->inputs[i];

         if (!link) continue;

         switch (link->init_state) {

         case AVLINK_INIT:
             continue;
         case AVLINK_STARTINIT:

             av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
             return 0;

         case AVLINK_UNINIT:
             link->init_state = AVLINK_STARTINIT;
 

             if ((ret = avfilter_config_links(link->src)) < 0)
                 return ret;

             if (!(config_link = link->srcpad->config_props))

                 config_link  = avfilter_default_config_output_link;

             if ((ret = config_link(link)) < 0)
                 return ret;

             if (link->time_base.num == 0 && link->time_base.den == 0)

                 link->time_base = link->src && link->src->input_count ?
                     link->src->inputs[0]->time_base : AV_TIME_BASE_Q;

             if (link->sample_aspect_ratio.num == 0 && link->sample_aspect_ratio.den == 0)
                 link->sample_aspect_ratio = link->src->input_count ?
                     link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
 

             if (link->sample_rate == 0 && link->src && link->src->input_count)
                 link->sample_rate = link->src->inputs[0]->sample_rate;
 
             if (link->channel_layout == 0 && link->src && link->src->input_count)
                 link->channel_layout = link->src->inputs[0]->channel_layout;
 

             if ((config_link = link->dstpad->config_props))

                 if ((ret = config_link(link)) < 0)
                     return ret;

             link->init_state = AVLINK_INIT;
         }
     }
 

     return 0;
 }
 

 static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)

 {

     snprintf(buf, buf_size, "%s%s%s%s%s%s",

              perms & AV_PERM_READ      ? "r" : "",
              perms & AV_PERM_WRITE     ? "w" : "",
              perms & AV_PERM_PRESERVE  ? "p" : "",

              perms & AV_PERM_REUSE     ? "u" : "",

              perms & AV_PERM_REUSE2    ? "U" : "",
              perms & AV_PERM_NEG_LINESIZES ? "n" : "");

     return buf;
 }
 

 static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)

 {

     av_unused char buf[16];

     av_dlog(ctx,

             "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
             ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],

             ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
             ref->pts, ref->pos);

     if (ref->video) {

         av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",

                 ref->video->sample_aspect_ratio.num, ref->video->sample_aspect_ratio.den,

                 ref->video->w, ref->video->h,
                 !ref->video->interlaced     ? 'P' :         /* Progressive  */

                 ref->video->top_field_first ? 'T' : 'B',    /* Top / Bottom */
                 ref->video->key_frame,
                 av_get_picture_type_char(ref->video->pict_type));

     }

     if (ref->audio) {

         av_dlog(ctx, " cl:%"PRId64"d n:%d r:%d p:%d",

                 ref->audio->channel_layout,

                 ref->audio->nb_samples,

                 ref->audio->sample_rate,
                 ref->audio->planar);
     }
 

     av_dlog(ctx, "]%s", end ? "\n" : "");

 }
 

 static void ff_dlog_link(void *ctx, AVFilterLink *link, int end)

 {

     if (link->type == AVMEDIA_TYPE_VIDEO) {

         av_dlog(ctx,

                 "link[%p s:%dx%d fmt:%-16s %-16s->%-16s]%s",
                 link, link->w, link->h,
                 av_pix_fmt_descriptors[link->format].name,
                 link->src ? link->src->filter->name : "",
                 link->dst ? link->dst->filter->name : "",
                 end ? "\n" : "");

     } else {
         char buf[128];
         av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);
 

         av_dlog(ctx,

                 "link[%p r:%"PRId64" cl:%s fmt:%-16s %-16s->%-16s]%s",
                 link, link->sample_rate, buf,
                 av_get_sample_fmt_name(link->format),
                 link->src ? link->src->filter->name : "",
                 link->dst ? link->dst->filter->name : "",
                 end ? "\n" : "");
     }

 }
 

 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)

 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)

 {

     AVFilterBufferRef *ret = NULL;

     av_unused char buf[16];

     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
     av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);

     if (link->dstpad->get_video_buffer)
         ret = link->dstpad->get_video_buffer(link, perms, w, h);

     if (!ret)

         ret = avfilter_default_get_video_buffer(link, perms, w, h);

     if (ret)
         ret->type = AVMEDIA_TYPE_VIDEO;
 

     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);

     return ret;
 }
 

 AVFilterBufferRef *

 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,

                                           int w, int h, enum PixelFormat format)
 {
     AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
     AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
 
     if (!pic || !picref)
         goto fail;
 
     picref->buf = pic;
     picref->buf->free = ff_avfilter_default_free_buffer;
     if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
         goto fail;
 

     pic->w = picref->video->w = w;
     pic->h = picref->video->h = h;

 
     /* make sure the buffer gets read permission or it's useless for output */
     picref->perms = perms | AV_PERM_READ;
 
     pic->refcount = 1;
     picref->type = AVMEDIA_TYPE_VIDEO;

     pic->format = picref->format = format;

 
     memcpy(pic->data,        data,          sizeof(pic->data));
     memcpy(pic->linesize,    linesize,      sizeof(pic->linesize));
     memcpy(picref->data,     pic->data,     sizeof(picref->data));
     memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
 
     return picref;
 
 fail:
     if (picref && picref->video)
         av_free(picref->video);
     av_free(picref);
     av_free(pic);
     return NULL;
 }
 

 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,

                                              enum AVSampleFormat sample_fmt, int nb_samples,

                                              int64_t channel_layout, int planar)
 {
     AVFilterBufferRef *ret = NULL;
 

     if (link->dstpad->get_audio_buffer)

         ret = link->dstpad->get_audio_buffer(link, perms, sample_fmt, nb_samples, channel_layout, planar);

 
     if (!ret)

         ret = avfilter_default_get_audio_buffer(link, perms, sample_fmt, nb_samples, channel_layout, planar);

 
     if (ret)
         ret->type = AVMEDIA_TYPE_AUDIO;
 
     return ret;
 }
 

 AVFilterBufferRef *
 avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms,
                                           int nb_samples, enum AVSampleFormat sample_fmt,
                                           int64_t channel_layout, int planar)
 {
     AVFilterBuffer *samples = av_mallocz(sizeof(AVFilterBuffer));
     AVFilterBufferRef *samplesref = av_mallocz(sizeof(AVFilterBufferRef));
 
     if (!samples || !samplesref)
         goto fail;
 
     samplesref->buf = samples;
     samplesref->buf->free = ff_avfilter_default_free_buffer;
     if (!(samplesref->audio = av_mallocz(sizeof(AVFilterBufferRefAudioProps))))
         goto fail;
 
     samplesref->audio->nb_samples     = nb_samples;
     samplesref->audio->channel_layout = channel_layout;
     samplesref->audio->planar         = planar;
 
     /* make sure the buffer gets read permission or it's useless for output */
     samplesref->perms = perms | AV_PERM_READ;
 
     samples->refcount = 1;
     samplesref->type = AVMEDIA_TYPE_AUDIO;
     samplesref->format = sample_fmt;
 
     memcpy(samples->data,        data,     sizeof(samples->data));
     memcpy(samples->linesize,    linesize, sizeof(samples->linesize));
     memcpy(samplesref->data,     data,     sizeof(samplesref->data));
     memcpy(samplesref->linesize, linesize, sizeof(samplesref->linesize));
 
     return samplesref;
 
 fail:
     if (samplesref && samplesref->audio)
         av_freep(&samplesref->audio);
     av_freep(&samplesref);
     av_freep(&samples);
     return NULL;
 }
 

 int avfilter_request_frame(AVFilterLink *link)

 {

     FF_DPRINTF_START(NULL, request_frame); ff_dlog_link(NULL, link, 1);

     if (link->srcpad->request_frame)
         return link->srcpad->request_frame(link);

     else if (link->src->inputs[0])

         return avfilter_request_frame(link->src->inputs[0]);
     else return -1;

 }
 

 int avfilter_poll_frame(AVFilterLink *link)
 {

     int i, min = INT_MAX;

     if (link->srcpad->poll_frame)
         return link->srcpad->poll_frame(link);

     for (i = 0; i < link->src->input_count; i++) {

         int val;

         if (!link->src->inputs[i])

             return -1;

         val = avfilter_poll_frame(link->src->inputs[i]);
         min = FFMIN(min, val);

     }

 
     return min;
 }
 

 /* XXX: should we do the duplicating of the picture ref here, instead of
  * forcing the source filter to do it? */

 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)

 {

     void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);

     AVFilterPad *dst = link->dstpad;

     int perms = picref->perms;

     FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);

     if (!(start_frame = dst->start_frame))

         start_frame = avfilter_default_start_frame;
 

     if (picref->linesize[0] < 0)
         perms |= AV_PERM_NEG_LINESIZES;

     /* prepare to copy the picture if it has insufficient permissions */

     if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {

         av_log(link->dst, AV_LOG_DEBUG,

                 "frame copy needed (have perms %x, need %x, reject %x)\n",

                 picref->perms,

                 link->dstpad->min_perms, link->dstpad->rej_perms);

         link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);

         link->src_buf = picref;
         avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);

     }
     else

         link->cur_buf = picref;

     start_frame(link, link->cur_buf);

 }
 
 void avfilter_end_frame(AVFilterLink *link)
 {
     void (*end_frame)(AVFilterLink *);
 

     if (!(end_frame = link->dstpad->end_frame))

         end_frame = avfilter_default_end_frame;
 
     end_frame(link);
 

     /* unreference the source picture if we're feeding the destination filter
      * a copied version dues to permission issues */

     if (link->src_buf) {

         avfilter_unref_buffer(link->src_buf);
         link->src_buf = NULL;

     }

 }
 

 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)

 {

     uint8_t *src[4], *dst[4];

     int i, j, vsub;

     void (*draw_slice)(AVFilterLink *, int, int, int);

     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);

     /* copy the slice if needed for permission reasons */

     if (link->src_buf) {

         vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;

         for (i = 0; i < 4; i++) {
             if (link->src_buf->data[i]) {

                 src[i] = link->src_buf-> data[i] +

                     (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];

                 dst[i] = link->cur_buf->data[i] +

                     (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];

             } else
                 src[i] = dst[i] = NULL;
         }

         for (i = 0; i < 4; i++) {

             int planew =

                 av_image_get_linesize(link->format, link->cur_buf->video->w, i);

             if (!src[i]) continue;

             for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {

                 memcpy(dst[i], src[i], planew);

                 src[i] += link->src_buf->linesize[i];

                 dst[i] += link->cur_buf->linesize[i];

             }
         }
     }
 

     if (!(draw_slice = link->dstpad->draw_slice))

         draw_slice = avfilter_default_draw_slice;

     draw_slice(link, y, h, slice_dir);

 }
 

 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref)
 {
     void (*filter_samples)(AVFilterLink *, AVFilterBufferRef *);

     AVFilterPad *dst = link->dstpad;

     int i;

     FF_DPRINTF_START(NULL, filter_samples); ff_dlog_link(NULL, link, 1);
 

     if (!(filter_samples = dst->filter_samples))
         filter_samples = avfilter_default_filter_samples;
 
     /* prepare to copy the samples if the buffer has insufficient permissions */
     if ((dst->min_perms & samplesref->perms) != dst->min_perms ||
         dst->rej_perms & samplesref->perms) {
 
         av_log(link->dst, AV_LOG_DEBUG,
                "Copying audio data in avfilter (have perms %x, need %x, reject %x)\n",

                samplesref->perms, link->dstpad->min_perms, link->dstpad->rej_perms);

 
         link->cur_buf = avfilter_default_get_audio_buffer(link, dst->min_perms,
                                                           samplesref->format,

                                                           samplesref->audio->nb_samples,

                                                           samplesref->audio->channel_layout,
                                                           samplesref->audio->planar);
         link->cur_buf->pts                = samplesref->pts;
         link->cur_buf->audio->sample_rate = samplesref->audio->sample_rate;
 
         /* Copy actual data into new samples buffer */

         for (i = 0; samplesref->data[i]; i++)
             memcpy(link->cur_buf->data[i], samplesref->data[i], samplesref->linesize[0]);

 
         avfilter_unref_buffer(samplesref);
     } else
         link->cur_buf = samplesref;
 
     filter_samples(link, link->cur_buf);
 }
 

 #define MAX_REGISTERED_AVFILTERS_NB 64
 
 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
 
 static int next_registered_avfilter_idx = 0;

 AVFilter *avfilter_get_by_name(const char *name)

 {

     int i;

     for (i = 0; registered_avfilters[i]; i++)
         if (!strcmp(registered_avfilters[i]->name, name))
             return registered_avfilters[i];

 
     return NULL;
 }
 

 int avfilter_register(AVFilter *filter)

 {

     if (next_registered_avfilter_idx == MAX_REGISTERED_AVFILTERS_NB)
         return -1;

     registered_avfilters[next_registered_avfilter_idx++] = filter;
     return 0;

 }
 

 AVFilter **av_filter_next(AVFilter **filter)
 {
     return filter ? ++filter : &registered_avfilters[0];
 }
 

 void avfilter_uninit(void)
 {

     memset(registered_avfilters, 0, sizeof(registered_avfilters));
     next_registered_avfilter_idx = 0;

 }
 
 static int pad_count(const AVFilterPad *pads)
 {
     int count;
 

     for(count = 0; pads->name; count ++) pads ++;

     return count;
 }
 
 static const char *filter_name(void *p)
 {
     AVFilterContext *filter = p;
     return filter->filter->name;
 }
 

 static const AVClass avfilter_class = {
     "AVFilter",

     filter_name,
     NULL,
     LIBAVUTIL_VERSION_INT,

 };
 

 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name)

 {

     AVFilterContext *ret;

     *filter_ctx = NULL;

 
     if (!filter)

         return AVERROR(EINVAL);

     ret = av_mallocz(sizeof(AVFilterContext));

     if (!ret)
         return AVERROR(ENOMEM);

     ret->av_class = &avfilter_class;

     ret->filter   = filter;

     ret->name     = inst_name ? av_strdup(inst_name) : NULL;

     if (filter->priv_size) {

         ret->priv     = av_mallocz(filter->priv_size);

         if (!ret->priv)
             goto err;
     }

     ret->input_count  = pad_count(filter->inputs);

     if (ret->input_count) {

         ret->input_pads   = av_malloc(sizeof(AVFilterPad) * ret->input_count);

         if (!ret->input_pads)
             goto err;

         memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->input_count);
         ret->inputs       = av_mallocz(sizeof(AVFilterLink*) * ret->input_count);

         if (!ret->inputs)
             goto err;

     }

     ret->output_count = pad_count(filter->outputs);

     if (ret->output_count) {

         ret->output_pads  = av_malloc(sizeof(AVFilterPad) * ret->output_count);

         if (!ret->output_pads)
             goto err;

         memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->output_count);
         ret->outputs      = av_mallocz(sizeof(AVFilterLink*) * ret->output_count);

         if (!ret->outputs)
             goto err;

     }

     *filter_ctx = ret;
     return 0;

 
 err:
     av_freep(&ret->inputs);
     av_freep(&ret->input_pads);
     ret->input_count = 0;
     av_freep(&ret->outputs);
     av_freep(&ret->output_pads);
     ret->output_count = 0;
     av_freep(&ret->priv);
     av_free(ret);
     return AVERROR(ENOMEM);

 }
 

 void avfilter_free(AVFilterContext *filter)

 {
     int i;

     AVFilterLink *link;

     if (filter->filter->uninit)

         filter->filter->uninit(filter);
 

     for (i = 0; i < filter->input_count; i++) {

         if ((link = filter->inputs[i])) {
             if (link->src)

                 link->src->outputs[link->srcpad - link->src->output_pads] = NULL;

             avfilter_formats_unref(&link->in_formats);
             avfilter_formats_unref(&link->out_formats);

         }

         avfilter_link_free(&link);

     }

     for (i = 0; i < filter->output_count; i++) {

         if ((link = filter->outputs[i])) {
             if (link->dst)

                 link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;

             avfilter_formats_unref(&link->in_formats);
             avfilter_formats_unref(&link->out_formats);

         }

         avfilter_link_free(&link);

     }
 

     av_freep(&filter->name);
     av_freep(&filter->input_pads);
     av_freep(&filter->output_pads);
     av_freep(&filter->inputs);
     av_freep(&filter->outputs);
     av_freep(&filter->priv);

     av_free(filter);
 }
 

 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)

 {

     int ret=0;

     if (filter->filter->init)

         ret = filter->filter->init(filter, args, opaque);
     return ret;

 }