Initial stab at an API

Commited in SoC by Bobby Bingham on 2007-06-29 17:03:03

Originally committed as revision 11965 to svn://svn.ffmpeg.org/ffmpeg/trunk

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 <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "avfilter.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);
+
+    ref->data[0] = pic->data[0];
+    ref->data[1] = pic->data[1];
+    ref->data[2] = pic->data[2];
+    ref->data[3] = pic->data[3];
+
+    return ref;
+}
+
+void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
+{
+    link->cur_pic = picref;
+}
+
+void avfilter_default_end_frame(AVFilterLink *link)
+{
+    avfilter_unref_pic(link->cur_pic);
+    link->cur_pic = NULL;
+}
+
+AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref)
+{
+    AVFilterPicRef *ret = av_malloc(sizeof(AVFilterPicRef));
+    memcpy(ret, ref, sizeof(AVFilterPicRef));
+    ret->pic->refcount ++;
+    return ret;
+}
+
+void avfilter_unref_pic(AVFilterPicRef *ref)
+{
+    if(-- ref->pic->refcount == 0)
+        ref->pic->free(ref->pic);
+    av_free(ref);
+}
+
+int avfilter_link(AVFilterContext *src, unsigned srcpad,
+                  AVFilterContext *dst, unsigned dstpad)
+{
+    AVFilterLink *link;
+
+    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;
+
+    src->filter->outputs[dstpad].set_video_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)
+{
+    link->src->filter->outputs[link->srcpad].request_frame(link);
+}
+
+/* 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)
+{
+}
+
+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)
+{
+    AVFilterContext *ret = av_malloc(sizeof(AVFilterContext));
+
+    ret->av_class = av_mallocz(sizeof(AVClass));
+    ret->av_class->item_name = filter_name;
+    ret->filter   = filter;
+    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->inputs);
+    av_free(filter->outputs);
+    av_free(filter->priv);
+    av_free(filter->av_class);
+    av_free(filter);
+}
+
+AVFilterContext *avfilter_create_by_name(char *name)
+{
+    AVFilter *filt;
+
+    if(!(filt = avfilter_get_by_name(name))) return NULL;
+    return avfilter_create(filt);
+}
+
+int avfilter_init_filter(AVFilterContext *filter)
+{
+    int ret, i;
+
+    if(filter->filter->init)
+        if((ret = filter->filter->init(filter))) return ret;
+    for(i = 0; i < pad_count(filter->filter->outputs); i ++)
+        if(filter->outputs[i])
+            filter->filter->outputs[i].set_video_props(filter->outputs[i]);
+    return 0;
+}
+