[libav.git] / libavfilter / avfilter.c

/*
 * 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
 */

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "avfilter.h"
#include "allfilters.h"

/** list of registered filters, sorted by name */
static int filter_count = 0;
static AVFilter **filters = NULL;

/* TODO: buffer pool.  see comment for avfilter_default_get_video_buffer() */
void avfilter_default_free_video_buffer(AVFilterPic *pic)
{
    avpicture_free((AVPicture *) pic);
    av_free(pic);
}

/* TODO: set the buffer's priv member to a context structure for the whole
 * filter chain.  This will allow for a buffer pool instead of the constant
 * alloc & free cycle currently implemented. */
AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms)
{
    AVFilterPic *pic = av_mallocz(sizeof(AVFilterPic));
    AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));

    ref->pic   = pic;
    ref->w     = link->w;
    ref->h     = link->h;
    ref->perms = perms;

    pic->refcount = 1;
    pic->format   = link->format;
    pic->free     = avfilter_default_free_video_buffer;
    avpicture_alloc((AVPicture *)pic, pic->format, ref->w, ref->h);

    memcpy(ref->data,     pic->data,     sizeof(pic->data));
    memcpy(ref->linesize, pic->linesize, sizeof(pic->linesize));

    return ref;
}

void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
{
    AVFilterLink *out = link->dst->outputs[0];

    link->cur_pic = picref;

    if(out) {
        out->outpic      = avfilter_get_video_buffer(out, AV_PERM_WRITE);
        out->outpic->pts = picref->pts;
        avfilter_start_frame(out, avfilter_ref_pic(out->outpic, ~0));
    }
}

void avfilter_default_end_frame(AVFilterLink *link)
{
    AVFilterLink *out = link->dst->outputs[0];

    avfilter_unref_pic(link->cur_pic);
    link->cur_pic = NULL;

    if(out) {
        avfilter_unref_pic(out->outpic);
        out->outpic = NULL;
        avfilter_end_frame(out);
    }
}

AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask)
{
    AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
    memcpy(ret, ref, sizeof(AVFilterPicRef));
    ret->perms &= pmask;
    ret->pic->refcount ++;
    return ret;
}

void avfilter_unref_pic(AVFilterPicRef *ref)
{
    if(-- ref->pic->refcount == 0)
        ref->pic->free(ref->pic);
    av_free(ref);
}

/**
 * default config_link() implementation for output video links to simplify
 * the implementation of one input one output video filters */
static int default_config_output_link(AVFilterLink *link)
{
    link->w = link->src->inputs[0]->w;
    link->h = link->src->inputs[0]->h;

    return 0;
}

/**
 * default query_formats() implementation for output video links to simplify
 * the implementation of one input one output video filters */
static int *default_query_output_formats(AVFilterLink *link)
{
    return avfilter_make_format_list(1, link->src->inputs[0]->format);
}

int avfilter_link(AVFilterContext *src, unsigned srcpad,
                  AVFilterContext *dst, unsigned dstpad)
{
    AVFilterLink *link;
    int *fmts[2], i, j;

    if(src->outputs[srcpad] || dst->inputs[dstpad])
        return -1;

    src->outputs[srcpad] =
    dst->inputs[dstpad]  = link = av_malloc(sizeof(AVFilterLink));

    link->src     = src;
    link->dst     = dst;
    link->srcpad  = srcpad;
    link->dstpad  = dstpad;
    link->cur_pic = NULL;

    /* find a format both filters support - TODO: auto-insert conversion filter */
    link->format = -1;
    if(src->filter->outputs[srcpad].query_formats)
        fmts[0] = src->filter->outputs[srcpad].query_formats(link);
    else
        fmts[0] = default_query_output_formats(link);
    fmts[1] = dst->filter-> inputs[dstpad].query_formats(link);
    for(i = 0; fmts[0][i] != -1; i ++)
        for(j = 0; fmts[1][j] != -1; j ++)
            if(fmts[0][i] == fmts[1][j]) {
                link->format = fmts[0][i];
                goto format_done;
            }

format_done:
    av_free(fmts[0]);
    av_free(fmts[1]);
    if(link->format == -1) {
        /* failed to find a format.  fail at creating the link */
        av_free(link);
        src->outputs[srcpad] = NULL;
        dst->inputs[dstpad]  = NULL;
        return -1;
    }

    if (src->filter->outputs[srcpad].config_props)
        src->filter->outputs[srcpad].config_props(link);
    else
        default_config_output_link(link);

    if (dst->filter->inputs[dstpad].config_props)
        dst->filter->inputs[dstpad].config_props(link);

    return 0;
}

AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms)
{
    AVFilterPicRef *ret = NULL;

    if(link->dst->filter->inputs[link->dstpad].get_video_buffer)
        ret = link->dst->filter->inputs[link->dstpad].get_video_buffer(link, perms);

    if(!ret)
        ret = avfilter_default_get_video_buffer(link, perms);

    return ret;
}

void avfilter_request_frame(AVFilterLink *link)
{
    const AVFilterPad *pad = &link->src->filter->outputs[link->srcpad];

    if(pad->request_frame)
        pad->request_frame(link);
    else if(link->src->inputs[0])
        avfilter_request_frame(link->src->inputs[0]);
}

/* 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, AVFilterPicRef *picref)
{
    void (*start_frame)(AVFilterLink *, AVFilterPicRef *);

    start_frame = link->dst->filter->inputs[link->dstpad].start_frame;
    if(!start_frame)
        start_frame = avfilter_default_start_frame;

    start_frame(link, picref);
}

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

    end_frame = link->dst->filter->inputs[link->dstpad].end_frame;
    if(!end_frame)
        end_frame = avfilter_default_end_frame;

    end_frame(link);
}

void avfilter_draw_slice(AVFilterLink *link, uint8_t *data[4], int y, int h)
{
    link->dst->filter->inputs[link->dstpad].draw_slice(link, data, y, h);
}

static int filter_cmp(const void *aa, const void *bb)
{
    const AVFilter *a = *(const AVFilter **)aa, *b = *(const AVFilter **)bb;
    return strcmp(a->name, b->name);
}

AVFilter *avfilter_get_by_name(char *name)
{
    AVFilter key = { .name = name, };
    AVFilter *key2 = &key;
    AVFilter **ret;

    ret = bsearch(&key2, filters, filter_count, sizeof(AVFilter **), filter_cmp);
    if(ret)
        return *ret;
    return NULL;
}

/* FIXME: insert in order, rather than insert at end + resort */
void avfilter_register(AVFilter *filter)
{
    filters = av_realloc(filters, sizeof(AVFilter*) * (filter_count+1));
    filters[filter_count] = filter;
    qsort(filters, ++filter_count, sizeof(AVFilter **), filter_cmp);
}

void avfilter_init(void)
{
    avfilter_register(&vsrc_dummy);
    avfilter_register(&vsrc_ppm);
    avfilter_register(&vf_crop);
    avfilter_register(&vf_passthrough);
    avfilter_register(&vf_rgb2bgr);
    avfilter_register(&vf_slicify);
    avfilter_register(&vo_sdl);
}

void avfilter_uninit(void)
{
    av_freep(&filters);
    filter_count = 0;
}

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

    for(count = 0; p->name; count ++) p ++;
    return count;
}

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

AVFilterContext *avfilter_create(AVFilter *filter, char *inst_name)
{
    AVFilterContext *ret = av_malloc(sizeof(AVFilterContext));

    ret->av_class = av_mallocz(sizeof(AVClass));
    ret->av_class->item_name = filter_name;
    ret->filter   = filter;
    ret->name     = inst_name ? av_strdup(inst_name) : NULL;
    ret->inputs   = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->inputs));
    ret->outputs  = av_mallocz(sizeof(AVFilterLink*) * pad_count(filter->outputs));
    ret->priv     = av_mallocz(filter->priv_size);

    return ret;
}

void avfilter_destroy(AVFilterContext *filter)
{
    int i;

    if(filter->filter->uninit)
        filter->filter->uninit(filter);

    for(i = 0; i < pad_count(filter->filter->inputs); i ++) {
        if(filter->inputs[i])
            filter->inputs[i]->src->outputs[filter->inputs[i]->srcpad] = NULL;
        av_free(filter->inputs[i]);
    }
    for(i = 0; i < pad_count(filter->filter->outputs); i ++) {
        if(filter->outputs[i])
            filter->outputs[i]->dst->inputs[filter->outputs[i]->dstpad] = NULL;
        av_free(filter->outputs[i]);
    }

    av_free(filter->name);
    av_free(filter->inputs);
    av_free(filter->outputs);
    av_free(filter->priv);
    av_free(filter->av_class);
    av_free(filter);
}

AVFilterContext *avfilter_create_by_name(char *name, char *inst_name)
{
    AVFilter *filt;

    if(!(filt = avfilter_get_by_name(name))) return NULL;
    return avfilter_create(filt, inst_name);
}

int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
{
    int ret, i;

    if(filter->filter->init)
        if((ret = filter->filter->init(filter, args, opaque))) return ret;
    return 0;
}

int *avfilter_make_format_list(int len, ...)
{
    int *ret, i;
    va_list vl;

    ret = av_malloc(sizeof(int) * (len + 1));
    va_start(vl, len);
    for(i = 0; i < len; i ++)
        ret[i] = va_arg(vl, int);
    va_end(vl);
    ret[len] = -1;

    return ret;
}
Commit	Line	Data
4dbbcdee VS	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
e0752603	22	#include <stdarg.h>
4dbbcdee VS	23	#include <stdlib.h>
	24	#include <string.h>
	25	#include <stdio.h>
	26
	27	#include "avfilter.h"
d72a138e	28	#include "allfilters.h"
4dbbcdee VS	29
	30	/** list of registered filters, sorted by name */
	31	static int filter_count = 0;
	32	static AVFilter **filters = NULL;
	33
	34	/* TODO: buffer pool. see comment for avfilter_default_get_video_buffer() */
	35	void avfilter_default_free_video_buffer(AVFilterPic *pic)
	36	{
	37	avpicture_free((AVPicture *) pic);
	38	av_free(pic);
	39	}
	40
	41	/* TODO: set the buffer's priv member to a context structure for the whole
	42	* filter chain. This will allow for a buffer pool instead of the constant
	43	* alloc & free cycle currently implemented. */
	44	AVFilterPicRef avfilter_default_get_video_buffer(AVFilterLink link, int perms)
	45	{
	46	AVFilterPic *pic = av_mallocz(sizeof(AVFilterPic));
	47	AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
	48
1653c11f VS	49	ref->pic = pic;
	50	ref->w = link->w;
	51	ref->h = link->h;
4dbbcdee VS	52	ref->perms = perms;
	53
	54	pic->refcount = 1;
1653c11f VS	55	pic->format = link->format;
1653c11f VS	56	pic->free = avfilter_default_free_video_buffer;
4dbbcdee VS	57	avpicture_alloc((AVPicture *)pic, pic->format, ref->w, ref->h);
4dbbcdee VS	58
92beffdc	59	memcpy(ref->data, pic->data, sizeof(pic->data));
a4ca7389	60	memcpy(ref->linesize, pic->linesize, sizeof(pic->linesize));
4dbbcdee VS	61
	62	return ref;
	63	}
	64
	65	void avfilter_default_start_frame(AVFilterLink link, AVFilterPicRef picref)
	66	{
3628fbe0 VS	67	AVFilterLink *out = link->dst->outputs[0];
3628fbe0 VS	68
4dbbcdee	69	link->cur_pic = picref;
3628fbe0 VS	70
3628fbe0 VS	71	if(out) {
1653c11f	72	out->outpic = avfilter_get_video_buffer(out, AV_PERM_WRITE);
af838d4c	73	out->outpic->pts = picref->pts;
3628fbe0 VS	74	avfilter_start_frame(out, avfilter_ref_pic(out->outpic, ~0));
3628fbe0 VS	75	}
4dbbcdee VS	76	}
	77
	78	void avfilter_default_end_frame(AVFilterLink *link)
	79	{
3628fbe0 VS	80	AVFilterLink *out = link->dst->outputs[0];
3628fbe0 VS	81
4dbbcdee VS	82	avfilter_unref_pic(link->cur_pic);
4dbbcdee VS	83	link->cur_pic = NULL;
3628fbe0 VS	84
	85	if(out) {
	86	avfilter_unref_pic(out->outpic);
	87	out->outpic = NULL;
	88	avfilter_end_frame(out);
	89	}
4dbbcdee VS	90	}
4dbbcdee VS	91
efb36bfc	92	AVFilterPicRef avfilter_ref_pic(AVFilterPicRef ref, int pmask)
4dbbcdee VS	93	{
	94	AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
	95	memcpy(ret, ref, sizeof(AVFilterPicRef));
efb36bfc	96	ret->perms &= pmask;
4dbbcdee VS	97	ret->pic->refcount ++;
	98	return ret;
	99	}
	100
	101	void avfilter_unref_pic(AVFilterPicRef *ref)
	102	{
	103	if(-- ref->pic->refcount == 0)
	104	ref->pic->free(ref->pic);
	105	av_free(ref);
	106	}
	107
102fb0e3 VS	108	/**
	109	* default config_link() implementation for output video links to simplify
	110	* the implementation of one input one output video filters */
	111	static int default_config_output_link(AVFilterLink *link)
	112	{
	113	link->w = link->src->inputs[0]->w;
	114	link->h = link->src->inputs[0]->h;
	115
	116	return 0;
	117	}
	118
	119	/**
	120	* default query_formats() implementation for output video links to simplify
	121	* the implementation of one input one output video filters */
	122	static int default_query_output_formats(AVFilterLink link)
	123	{
	124	return avfilter_make_format_list(1, link->src->inputs[0]->format);
	125	}
	126
4dbbcdee VS	127	int avfilter_link(AVFilterContext *src, unsigned srcpad,
	128	AVFilterContext *dst, unsigned dstpad)
	129	{
	130	AVFilterLink *link;
e0752603	131	int *fmts[2], i, j;
4dbbcdee VS	132
	133	if(src->outputs[srcpad] \|\| dst->inputs[dstpad])
	134	return -1;
	135
	136	src->outputs[srcpad] =
	137	dst->inputs[dstpad] = link = av_malloc(sizeof(AVFilterLink));
	138
1653c11f VS	139	link->src = src;
	140	link->dst = dst;
	141	link->srcpad = srcpad;
	142	link->dstpad = dstpad;
4dbbcdee VS	143	link->cur_pic = NULL;
4dbbcdee VS	144
e0752603	145	/* find a format both filters support - TODO: auto-insert conversion filter */
998a7aa3	146	link->format = -1;
102fb0e3 VS	147	if(src->filter->outputs[srcpad].query_formats)
	148	fmts[0] = src->filter->outputs[srcpad].query_formats(link);
	149	else
	150	fmts[0] = default_query_output_formats(link);
ba6b9035	151	fmts[1] = dst->filter-> inputs[dstpad].query_formats(link);
e0752603 VS	152	for(i = 0; fmts[0][i] != -1; i ++)
	153	for(j = 0; fmts[1][j] != -1; j ++)
	154	if(fmts[0][i] == fmts[1][j]) {
	155	link->format = fmts[0][i];
	156	goto format_done;
	157	}
	158
	159	format_done:
	160	av_free(fmts[0]);
	161	av_free(fmts[1]);
	162	if(link->format == -1) {
	163	/* failed to find a format. fail at creating the link */
	164	av_free(link);
	165	src->outputs[srcpad] = NULL;
	166	dst->inputs[dstpad] = NULL;
	167	return -1;
	168	}
	169
102fb0e3 VS	170	if (src->filter->outputs[srcpad].config_props)
	171	src->filter->outputs[srcpad].config_props(link);
	172	else
	173	default_config_output_link(link);
	174
	175	if (dst->filter->inputs[dstpad].config_props)
	176	dst->filter->inputs[dstpad].config_props(link);
	177
4dbbcdee VS	178	return 0;
	179	}
	180
	181	AVFilterPicRef avfilter_get_video_buffer(AVFilterLink link, int perms)
	182	{
	183	AVFilterPicRef *ret = NULL;
	184
	185	if(link->dst->filter->inputs[link->dstpad].get_video_buffer)
	186	ret = link->dst->filter->inputs[link->dstpad].get_video_buffer(link, perms);
	187
	188	if(!ret)
	189	ret = avfilter_default_get_video_buffer(link, perms);
	190
	191	return ret;
	192	}
	193
	194	void avfilter_request_frame(AVFilterLink *link)
	195	{
9586ba3a VS	196	const AVFilterPad *pad = &link->src->filter->outputs[link->srcpad];
	197
	198	if(pad->request_frame)
	199	pad->request_frame(link);
	200	else if(link->src->inputs[0])
	201	avfilter_request_frame(link->src->inputs[0]);
4dbbcdee VS	202	}
	203
	204	/* XXX: should we do the duplicating of the picture ref here, instead of
	205	* forcing the source filter to do it? */
	206	void avfilter_start_frame(AVFilterLink link, AVFilterPicRef picref)
	207	{
	208	void (start_frame)(AVFilterLink , AVFilterPicRef *);
	209
	210	start_frame = link->dst->filter->inputs[link->dstpad].start_frame;
	211	if(!start_frame)
	212	start_frame = avfilter_default_start_frame;
	213
	214	start_frame(link, picref);
	215	}
	216
	217	void avfilter_end_frame(AVFilterLink *link)
	218	{
	219	void (end_frame)(AVFilterLink );
	220
	221	end_frame = link->dst->filter->inputs[link->dstpad].end_frame;
	222	if(!end_frame)
	223	end_frame = avfilter_default_end_frame;
	224
	225	end_frame(link);
	226	}
	227
	228	void avfilter_draw_slice(AVFilterLink link, uint8_t data[4], int y, int h)
	229	{
	230	link->dst->filter->inputs[link->dstpad].draw_slice(link, data, y, h);
	231	}
	232
	233	static int filter_cmp(const void aa, const void bb)
	234	{
	235	const AVFilter a = (const AVFilter *)aa, b = (const AVFilter *)bb;
	236	return strcmp(a->name, b->name);
	237	}
	238
	239	AVFilter avfilter_get_by_name(char name)
	240	{
	241	AVFilter key = { .name = name, };
	242	AVFilter *key2 = &key;
	243	AVFilter **ret;
	244
	245	ret = bsearch(&key2, filters, filter_count, sizeof(AVFilter **), filter_cmp);
	246	if(ret)
	247	return *ret;
	248	return NULL;
	249	}
	250
	251	/* FIXME: insert in order, rather than insert at end + resort */
	252	void avfilter_register(AVFilter *filter)
	253	{
	254	filters = av_realloc(filters, sizeof(AVFilter) (filter_count+1));
	255	filters[filter_count] = filter;
	256	qsort(filters, ++filter_count, sizeof(AVFilter **), filter_cmp);
	257	}
	258
	259	void avfilter_init(void)
	260	{
d72a138e	261	avfilter_register(&vsrc_dummy);
eaf7eb66	262	avfilter_register(&vsrc_ppm);
d72a138e VS	263	avfilter_register(&vf_crop);
d72a138e VS	264	avfilter_register(&vf_passthrough);
72e3037a	265	avfilter_register(&vf_rgb2bgr);
ce356b09	266	avfilter_register(&vf_slicify);
d72a138e	267	avfilter_register(&vo_sdl);
4dbbcdee VS	268	}
	269
	270	void avfilter_uninit(void)
	271	{
	272	av_freep(&filters);
	273	filter_count = 0;
	274	}
	275
	276	static int pad_count(const AVFilterPad *pads)
	277	{
	278	AVFilterPad p = (AVFilterPad ) pads;
	279	int count;
	280
	281	for(count = 0; p->name; count ++) p ++;
	282	return count;
	283	}
	284
	285	static const char filter_name(void p)
	286	{
	287	AVFilterContext *filter = p;
	288	return filter->filter->name;
	289	}
	290
6ae82d1e	291	AVFilterContext avfilter_create(AVFilter filter, char *inst_name)
4dbbcdee VS	292	{
	293	AVFilterContext *ret = av_malloc(sizeof(AVFilterContext));
	294
	295	ret->av_class = av_mallocz(sizeof(AVClass));
	296	ret->av_class->item_name = filter_name;
	297	ret->filter = filter;
2350e69c	298	ret->name = inst_name ? av_strdup(inst_name) : NULL;
4dbbcdee VS	299	ret->inputs = av_mallocz(sizeof(AVFilterLink) pad_count(filter->inputs));
	300	ret->outputs = av_mallocz(sizeof(AVFilterLink) pad_count(filter->outputs));
	301	ret->priv = av_mallocz(filter->priv_size);
	302
	303	return ret;
	304	}
	305
	306	void avfilter_destroy(AVFilterContext *filter)
	307	{
	308	int i;
	309
	310	if(filter->filter->uninit)
	311	filter->filter->uninit(filter);
	312
	313	for(i = 0; i < pad_count(filter->filter->inputs); i ++) {
	314	if(filter->inputs[i])
	315	filter->inputs[i]->src->outputs[filter->inputs[i]->srcpad] = NULL;
	316	av_free(filter->inputs[i]);
	317	}
	318	for(i = 0; i < pad_count(filter->filter->outputs); i ++) {
	319	if(filter->outputs[i])
	320	filter->outputs[i]->dst->inputs[filter->outputs[i]->dstpad] = NULL;
	321	av_free(filter->outputs[i]);
	322	}
	323
2350e69c	324	av_free(filter->name);
4dbbcdee VS	325	av_free(filter->inputs);
	326	av_free(filter->outputs);
	327	av_free(filter->priv);
	328	av_free(filter->av_class);
	329	av_free(filter);
	330	}
	331
6ae82d1e	332	AVFilterContext avfilter_create_by_name(char name, char *inst_name)
4dbbcdee VS	333	{
	334	AVFilter *filt;
	335
	336	if(!(filt = avfilter_get_by_name(name))) return NULL;
6ae82d1e	337	return avfilter_create(filt, inst_name);
4dbbcdee VS	338	}
4dbbcdee VS	339
a360f71e	340	int avfilter_init_filter(AVFilterContext filter, const char args, void *opaque)
4dbbcdee VS	341	{
	342	int ret, i;
	343
	344	if(filter->filter->init)
a360f71e	345	if((ret = filter->filter->init(filter, args, opaque))) return ret;
4dbbcdee VS	346	return 0;
	347	}
	348
e0752603 VS	349	int *avfilter_make_format_list(int len, ...)
	350	{
	351	int *ret, i;
	352	va_list vl;
	353
	354	ret = av_malloc(sizeof(int) * (len + 1));
	355	va_start(vl, len);
	356	for(i = 0; i < len; i ++)
	357	ret[i] = va_arg(vl, int);
	358	va_end(vl);
	359	ret[len] = -1;
	360
	361	return ret;
	362	}
	363