3 * Copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "libavutil/pixdesc.h"
25 #include "libavutil/rational.h"
26 #include "libavutil/audioconvert.h"
27 #include "libavutil/imgutils.h"
28 #include "libavutil/avassert.h"
32 unsigned avfilter_version(void) {
33 return LIBAVFILTER_VERSION_INT;
36 const char *avfilter_configuration(void)
38 return FFMPEG_CONFIGURATION;
41 const char *avfilter_license(void)
43 #define LICENSE_PREFIX "libavfilter license: "
44 return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
47 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)
49 AVFilterBufferRef *ret = av_malloc(sizeof(AVFilterBufferRef));
53 if (ref->type == AVMEDIA_TYPE_VIDEO) {
54 ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));
59 *ret->video = *ref->video;
60 } else if (ref->type == AVMEDIA_TYPE_AUDIO) {
61 ret->audio = av_malloc(sizeof(AVFilterBufferRefAudioProps));
66 *ret->audio = *ref->audio;
69 ret->buf->refcount ++;
73 static void store_in_pool(AVFilterBufferRef *ref)
76 AVFilterPool *pool= ref->buf->priv;
78 av_assert0(ref->buf->data[0]);
80 if (pool->count == POOL_SIZE) {
81 AVFilterBufferRef *ref1 = pool->pic[0];
82 av_freep(&ref1->video);
83 av_freep(&ref1->audio);
84 av_freep(&ref1->buf->data[0]);
87 memmove(&pool->pic[0], &pool->pic[1], sizeof(void*)*(POOL_SIZE-1));
89 pool->pic[POOL_SIZE-1] = NULL;
92 for (i = 0; i < POOL_SIZE; i++) {
101 void avfilter_unref_buffer(AVFilterBufferRef *ref)
105 if (!(--ref->buf->refcount)) {
106 if (!ref->buf->free) {
110 ref->buf->free(ref->buf);
112 av_freep(&ref->video);
113 av_freep(&ref->audio);
117 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
118 AVFilterPad **pads, AVFilterLink ***links,
123 idx = FFMIN(idx, *count);
125 *pads = av_realloc(*pads, sizeof(AVFilterPad) * (*count + 1));
126 *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
127 memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad) * (*count-idx));
128 memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
129 memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
130 (*links)[idx] = NULL;
133 for (i = idx+1; i < *count; i++)
135 (*(unsigned *)((uint8_t *) *links[i] + padidx_off))++;
138 int avfilter_link(AVFilterContext *src, unsigned srcpad,
139 AVFilterContext *dst, unsigned dstpad)
143 if (src->output_count <= srcpad || dst->input_count <= dstpad ||
144 src->outputs[srcpad] || dst->inputs[dstpad])
147 if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
148 av_log(src, AV_LOG_ERROR,
149 "Media type mismatch between the '%s' filter output pad %d and the '%s' filter input pad %d\n",
150 src->name, srcpad, dst->name, dstpad);
151 return AVERROR(EINVAL);
154 src->outputs[srcpad] =
155 dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));
159 link->srcpad = &src->output_pads[srcpad];
160 link->dstpad = &dst->input_pads[dstpad];
161 link->type = src->output_pads[srcpad].type;
162 assert(PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);
168 void avfilter_link_free(AVFilterLink **link)
175 for (i = 0; i < POOL_SIZE; i++) {
176 if ((*link)->pool->pic[i]) {
177 AVFilterBufferRef *picref = (*link)->pool->pic[i];
178 /* free buffer: picrefs stored in the pool are not
179 * supposed to contain a free callback */
180 av_freep(&picref->buf->data[0]);
181 av_freep(&picref->buf);
183 av_freep(&picref->audio);
184 av_freep(&picref->video);
185 av_freep(&(*link)->pool->pic[i]);
188 (*link)->pool->count = 0;
189 // av_freep(&(*link)->pool);
194 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
195 unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
198 unsigned dstpad_idx = link->dstpad - link->dst->input_pads;
200 av_log(link->dst, AV_LOG_INFO, "auto-inserting filter '%s' "
201 "between the filter '%s' and the filter '%s'\n",
202 filt->name, link->src->name, link->dst->name);
204 link->dst->inputs[dstpad_idx] = NULL;
205 if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {
206 /* failed to link output filter to new filter */
207 link->dst->inputs[dstpad_idx] = link;
211 /* re-hookup the link to the new destination filter we inserted */
213 link->dstpad = &filt->input_pads[filt_srcpad_idx];
214 filt->inputs[filt_srcpad_idx] = link;
216 /* if any information on supported media formats already exists on the
217 * link, we need to preserve that */
218 if (link->out_formats)
219 avfilter_formats_changeref(&link->out_formats,
220 &filt->outputs[filt_dstpad_idx]->out_formats);
221 if (link->out_chlayouts)
222 avfilter_formats_changeref(&link->out_chlayouts,
223 &filt->outputs[filt_dstpad_idx]->out_chlayouts);
224 if (link->out_packing)
225 avfilter_formats_changeref(&link->out_packing,
226 &filt->outputs[filt_dstpad_idx]->out_packing);
231 int avfilter_config_links(AVFilterContext *filter)
233 int (*config_link)(AVFilterLink *);
237 for (i = 0; i < filter->input_count; i ++) {
238 AVFilterLink *link = filter->inputs[i];
242 switch (link->init_state) {
245 case AVLINK_STARTINIT:
246 av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
249 link->init_state = AVLINK_STARTINIT;
251 if ((ret = avfilter_config_links(link->src)) < 0)
254 if (!(config_link = link->srcpad->config_props))
255 config_link = avfilter_default_config_output_link;
256 if ((ret = config_link(link)) < 0)
259 if (link->time_base.num == 0 && link->time_base.den == 0)
260 link->time_base = link->src && link->src->input_count ?
261 link->src->inputs[0]->time_base : AV_TIME_BASE_Q;
263 if (link->sample_aspect_ratio.num == 0 && link->sample_aspect_ratio.den == 0)
264 link->sample_aspect_ratio = link->src->input_count ?
265 link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
267 if (link->sample_rate == 0 && link->src && link->src->input_count)
268 link->sample_rate = link->src->inputs[0]->sample_rate;
270 if (link->channel_layout == 0 && link->src && link->src->input_count)
271 link->channel_layout = link->src->inputs[0]->channel_layout;
273 if ((config_link = link->dstpad->config_props))
274 if ((ret = config_link(link)) < 0)
277 link->init_state = AVLINK_INIT;
284 static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
286 snprintf(buf, buf_size, "%s%s%s%s%s%s",
287 perms & AV_PERM_READ ? "r" : "",
288 perms & AV_PERM_WRITE ? "w" : "",
289 perms & AV_PERM_PRESERVE ? "p" : "",
290 perms & AV_PERM_REUSE ? "u" : "",
291 perms & AV_PERM_REUSE2 ? "U" : "",
292 perms & AV_PERM_NEG_LINESIZES ? "n" : "");
296 static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
298 av_unused char buf[16];
300 "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
301 ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
302 ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
306 av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
307 ref->video->sample_aspect_ratio.num, ref->video->sample_aspect_ratio.den,
308 ref->video->w, ref->video->h,
309 !ref->video->interlaced ? 'P' : /* Progressive */
310 ref->video->top_field_first ? 'T' : 'B', /* Top / Bottom */
311 ref->video->key_frame,
312 av_get_picture_type_char(ref->video->pict_type));
315 av_dlog(ctx, " cl:%"PRId64"d n:%d r:%d p:%d",
316 ref->audio->channel_layout,
317 ref->audio->nb_samples,
318 ref->audio->sample_rate,
322 av_dlog(ctx, "]%s", end ? "\n" : "");
325 static void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
327 if (link->type == AVMEDIA_TYPE_VIDEO) {
329 "link[%p s:%dx%d fmt:%-16s %-16s->%-16s]%s",
330 link, link->w, link->h,
331 av_pix_fmt_descriptors[link->format].name,
332 link->src ? link->src->filter->name : "",
333 link->dst ? link->dst->filter->name : "",
337 av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);
340 "link[%p r:%"PRId64" cl:%s fmt:%-16s %-16s->%-16s]%s",
341 link, link->sample_rate, buf,
342 av_get_sample_fmt_name(link->format),
343 link->src ? link->src->filter->name : "",
344 link->dst ? link->dst->filter->name : "",
349 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)
351 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
353 AVFilterBufferRef *ret = NULL;
355 av_unused char buf[16];
356 FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
357 av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
359 if (link->dstpad->get_video_buffer)
360 ret = link->dstpad->get_video_buffer(link, perms, w, h);
363 ret = avfilter_default_get_video_buffer(link, perms, w, h);
366 ret->type = AVMEDIA_TYPE_VIDEO;
368 FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
374 avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
375 int w, int h, enum PixelFormat format)
377 AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
378 AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
384 picref->buf->free = ff_avfilter_default_free_buffer;
385 if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
388 pic->w = picref->video->w = w;
389 pic->h = picref->video->h = h;
391 /* make sure the buffer gets read permission or it's useless for output */
392 picref->perms = perms | AV_PERM_READ;
395 picref->type = AVMEDIA_TYPE_VIDEO;
396 pic->format = picref->format = format;
398 memcpy(pic->data, data, sizeof(pic->data));
399 memcpy(pic->linesize, linesize, sizeof(pic->linesize));
400 memcpy(picref->data, pic->data, sizeof(picref->data));
401 memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
406 if (picref && picref->video)
407 av_free(picref->video);
413 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
414 enum AVSampleFormat sample_fmt, int nb_samples,
415 int64_t channel_layout, int planar)
417 AVFilterBufferRef *ret = NULL;
419 if (link->dstpad->get_audio_buffer)
420 ret = link->dstpad->get_audio_buffer(link, perms, sample_fmt, nb_samples, channel_layout, planar);
423 ret = avfilter_default_get_audio_buffer(link, perms, sample_fmt, nb_samples, channel_layout, planar);
426 ret->type = AVMEDIA_TYPE_AUDIO;
432 avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms,
433 int nb_samples, enum AVSampleFormat sample_fmt,
434 int64_t channel_layout, int planar)
436 AVFilterBuffer *samples = av_mallocz(sizeof(AVFilterBuffer));
437 AVFilterBufferRef *samplesref = av_mallocz(sizeof(AVFilterBufferRef));
439 if (!samples || !samplesref)
442 samplesref->buf = samples;
443 samplesref->buf->free = ff_avfilter_default_free_buffer;
444 if (!(samplesref->audio = av_mallocz(sizeof(AVFilterBufferRefAudioProps))))
447 samplesref->audio->nb_samples = nb_samples;
448 samplesref->audio->channel_layout = channel_layout;
449 samplesref->audio->planar = planar;
451 /* make sure the buffer gets read permission or it's useless for output */
452 samplesref->perms = perms | AV_PERM_READ;
454 samples->refcount = 1;
455 samplesref->type = AVMEDIA_TYPE_AUDIO;
456 samplesref->format = sample_fmt;
458 memcpy(samples->data, data, sizeof(samples->data));
459 memcpy(samples->linesize, linesize, sizeof(samples->linesize));
460 memcpy(samplesref->data, data, sizeof(samplesref->data));
461 memcpy(samplesref->linesize, linesize, sizeof(samplesref->linesize));
466 if (samplesref && samplesref->audio)
467 av_freep(&samplesref->audio);
468 av_freep(&samplesref);
473 int avfilter_request_frame(AVFilterLink *link)
475 FF_DPRINTF_START(NULL, request_frame); ff_dlog_link(NULL, link, 1);
477 if (link->srcpad->request_frame)
478 return link->srcpad->request_frame(link);
479 else if (link->src->inputs[0])
480 return avfilter_request_frame(link->src->inputs[0]);
484 int avfilter_poll_frame(AVFilterLink *link)
486 int i, min = INT_MAX;
488 if (link->srcpad->poll_frame)
489 return link->srcpad->poll_frame(link);
491 for (i = 0; i < link->src->input_count; i++) {
493 if (!link->src->inputs[i])
495 val = avfilter_poll_frame(link->src->inputs[i]);
496 min = FFMIN(min, val);
502 /* XXX: should we do the duplicating of the picture ref here, instead of
503 * forcing the source filter to do it? */
504 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
506 void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);
507 AVFilterPad *dst = link->dstpad;
508 int perms = picref->perms;
510 FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);
512 if (!(start_frame = dst->start_frame))
513 start_frame = avfilter_default_start_frame;
515 if (picref->linesize[0] < 0)
516 perms |= AV_PERM_NEG_LINESIZES;
517 /* prepare to copy the picture if it has insufficient permissions */
518 if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {
519 av_log(link->dst, AV_LOG_DEBUG,
520 "frame copy needed (have perms %x, need %x, reject %x)\n",
522 link->dstpad->min_perms, link->dstpad->rej_perms);
524 link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);
525 link->src_buf = picref;
526 avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);
529 link->cur_buf = picref;
531 start_frame(link, link->cur_buf);
534 void avfilter_end_frame(AVFilterLink *link)
536 void (*end_frame)(AVFilterLink *);
538 if (!(end_frame = link->dstpad->end_frame))
539 end_frame = avfilter_default_end_frame;
543 /* unreference the source picture if we're feeding the destination filter
544 * a copied version dues to permission issues */
546 avfilter_unref_buffer(link->src_buf);
547 link->src_buf = NULL;
551 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
553 uint8_t *src[4], *dst[4];
555 void (*draw_slice)(AVFilterLink *, int, int, int);
557 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);
559 /* copy the slice if needed for permission reasons */
561 vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
563 for (i = 0; i < 4; i++) {
564 if (link->src_buf->data[i]) {
565 src[i] = link->src_buf-> data[i] +
566 (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];
567 dst[i] = link->cur_buf->data[i] +
568 (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];
570 src[i] = dst[i] = NULL;
573 for (i = 0; i < 4; i++) {
575 av_image_get_linesize(link->format, link->cur_buf->video->w, i);
577 if (!src[i]) continue;
579 for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {
580 memcpy(dst[i], src[i], planew);
581 src[i] += link->src_buf->linesize[i];
582 dst[i] += link->cur_buf->linesize[i];
587 if (!(draw_slice = link->dstpad->draw_slice))
588 draw_slice = avfilter_default_draw_slice;
589 draw_slice(link, y, h, slice_dir);
592 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref)
594 void (*filter_samples)(AVFilterLink *, AVFilterBufferRef *);
595 AVFilterPad *dst = link->dstpad;
598 FF_DPRINTF_START(NULL, filter_samples); ff_dlog_link(NULL, link, 1);
600 if (!(filter_samples = dst->filter_samples))
601 filter_samples = avfilter_default_filter_samples;
603 /* prepare to copy the samples if the buffer has insufficient permissions */
604 if ((dst->min_perms & samplesref->perms) != dst->min_perms ||
605 dst->rej_perms & samplesref->perms) {
607 av_log(link->dst, AV_LOG_DEBUG,
608 "Copying audio data in avfilter (have perms %x, need %x, reject %x)\n",
609 samplesref->perms, link->dstpad->min_perms, link->dstpad->rej_perms);
611 link->cur_buf = avfilter_default_get_audio_buffer(link, dst->min_perms,
613 samplesref->audio->nb_samples,
614 samplesref->audio->channel_layout,
615 samplesref->audio->planar);
616 link->cur_buf->pts = samplesref->pts;
617 link->cur_buf->audio->sample_rate = samplesref->audio->sample_rate;
619 /* Copy actual data into new samples buffer */
620 for (i = 0; samplesref->data[i]; i++)
621 memcpy(link->cur_buf->data[i], samplesref->data[i], samplesref->linesize[0]);
623 avfilter_unref_buffer(samplesref);
625 link->cur_buf = samplesref;
627 filter_samples(link, link->cur_buf);
630 #define MAX_REGISTERED_AVFILTERS_NB 64
632 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
634 static int next_registered_avfilter_idx = 0;
636 AVFilter *avfilter_get_by_name(const char *name)
640 for (i = 0; registered_avfilters[i]; i++)
641 if (!strcmp(registered_avfilters[i]->name, name))
642 return registered_avfilters[i];
647 int avfilter_register(AVFilter *filter)
649 if (next_registered_avfilter_idx == MAX_REGISTERED_AVFILTERS_NB)
652 registered_avfilters[next_registered_avfilter_idx++] = filter;
656 AVFilter **av_filter_next(AVFilter **filter)
658 return filter ? ++filter : ®istered_avfilters[0];
661 void avfilter_uninit(void)
663 memset(registered_avfilters, 0, sizeof(registered_avfilters));
664 next_registered_avfilter_idx = 0;
667 static int pad_count(const AVFilterPad *pads)
671 for(count = 0; pads->name; count ++) pads ++;
675 static const char *filter_name(void *p)
677 AVFilterContext *filter = p;
678 return filter->filter->name;
681 static const AVClass avfilter_class = {
685 LIBAVUTIL_VERSION_INT,
688 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name)
690 AVFilterContext *ret;
694 return AVERROR(EINVAL);
696 ret = av_mallocz(sizeof(AVFilterContext));
698 return AVERROR(ENOMEM);
700 ret->av_class = &avfilter_class;
701 ret->filter = filter;
702 ret->name = inst_name ? av_strdup(inst_name) : NULL;
703 if (filter->priv_size) {
704 ret->priv = av_mallocz(filter->priv_size);
709 ret->input_count = pad_count(filter->inputs);
710 if (ret->input_count) {
711 ret->input_pads = av_malloc(sizeof(AVFilterPad) * ret->input_count);
712 if (!ret->input_pads)
714 memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->input_count);
715 ret->inputs = av_mallocz(sizeof(AVFilterLink*) * ret->input_count);
720 ret->output_count = pad_count(filter->outputs);
721 if (ret->output_count) {
722 ret->output_pads = av_malloc(sizeof(AVFilterPad) * ret->output_count);
723 if (!ret->output_pads)
725 memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->output_count);
726 ret->outputs = av_mallocz(sizeof(AVFilterLink*) * ret->output_count);
735 av_freep(&ret->inputs);
736 av_freep(&ret->input_pads);
737 ret->input_count = 0;
738 av_freep(&ret->outputs);
739 av_freep(&ret->output_pads);
740 ret->output_count = 0;
741 av_freep(&ret->priv);
743 return AVERROR(ENOMEM);
746 void avfilter_free(AVFilterContext *filter)
751 if (filter->filter->uninit)
752 filter->filter->uninit(filter);
754 for (i = 0; i < filter->input_count; i++) {
755 if ((link = filter->inputs[i])) {
757 link->src->outputs[link->srcpad - link->src->output_pads] = NULL;
758 avfilter_formats_unref(&link->in_formats);
759 avfilter_formats_unref(&link->out_formats);
761 avfilter_link_free(&link);
763 for (i = 0; i < filter->output_count; i++) {
764 if ((link = filter->outputs[i])) {
766 link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;
767 avfilter_formats_unref(&link->in_formats);
768 avfilter_formats_unref(&link->out_formats);
770 avfilter_link_free(&link);
773 av_freep(&filter->name);
774 av_freep(&filter->input_pads);
775 av_freep(&filter->output_pads);
776 av_freep(&filter->inputs);
777 av_freep(&filter->outputs);
778 av_freep(&filter->priv);
782 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
786 if (filter->filter->init)
787 ret = filter->filter->init(filter, args, opaque);