PeerStreamer

/*

 * Filter layer - default implementations

 * 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 "libavcore/imgutils.h"

#include "avfilter.h"

/* TODO: buffer pool.  see comment for avfilter_default_get_video_buffer() */

static void avfilter_default_free_buffer(AVFilterBuffer *ptr)

{

    av_free(ptr->data[0]);

    av_free(ptr);

}

/* 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. */

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

{

    AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));

    AVFilterBufferRef *ref = av_mallocz(sizeof(AVFilterBufferRef));

    int i, tempsize;

    char *buf;

    ref->buf   = pic;

    ref->w     = w;

    ref->h     = h;

    /* make sure the buffer gets read permission or it's useless for output */

    ref->perms = perms | AV_PERM_READ;

    pic->refcount = 1;

    ref->format   = link->format;

    pic->free     = avfilter_default_free_buffer;

    av_fill_image_linesizes(pic->linesize, ref->format, ref->w);

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

        pic->linesize[i] = FFALIGN(pic->linesize[i], 16);

    tempsize = av_fill_image_pointers(pic->data, ref->format, ref->h, NULL, pic->linesize);

    buf = av_malloc(tempsize + 16); // +2 is needed for swscaler, +16 to be

                                    // SIMD-friendly

    av_fill_image_pointers(pic->data, ref->format, ref->h, buf, pic->linesize);

    memcpy(ref->data,     pic->data,     4*sizeof(pic->data[0]));

    memcpy(ref->linesize, pic->linesize, 4*sizeof(pic->linesize[0]));

    return ref;

}

void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)

{

    AVFilterLink *out = NULL;

    if(link->dst->output_count)

        out = link->dst->outputs[0];

    if(out) {

        out->out_buf      = avfilter_get_video_buffer(out, AV_PERM_WRITE, out->w, out->h);

        avfilter_copy_buffer_ref_props(out->out_buf, picref);

        avfilter_start_frame(out, avfilter_ref_buffer(out->out_buf, ~0));

    }

}

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

{

    AVFilterLink *out = NULL;

    if(link->dst->output_count)

        out = link->dst->outputs[0];

    if(out)

        avfilter_draw_slice(out, y, h, slice_dir);

}

void avfilter_default_end_frame(AVFilterLink *link)

{

    AVFilterLink *out = NULL;

    if(link->dst->output_count)

        out = link->dst->outputs[0];

    avfilter_unref_buffer(link->cur_buf);

    link->cur_buf = NULL;

    if(out) {

        if(out->out_buf) {

            avfilter_unref_buffer(out->out_buf);

            out->out_buf = NULL;

        }

        avfilter_end_frame(out);

    }

}

/**

 * default config_link() implementation for output video links to simplify

 * the implementation of one input one output video filters */

int avfilter_default_config_output_link(AVFilterLink *link)

{

    if(link->src->input_count && link->src->inputs[0]) {

        link->w = link->src->inputs[0]->w;

        link->h = link->src->inputs[0]->h;

    } else {

        /* XXX: any non-simple filter which would cause this branch to be taken

         * really should implement its own config_props() for this link. */

        return -1;

    }

    return 0;

}

/**

 * A helper for query_formats() which sets all links to the same list of

 * formats. If there are no links hooked to this filter, the list of formats is

 * freed.

 *

 * FIXME: this will need changed for filters with a mix of pad types

 * (video + audio, etc)

 */

void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)

{

    int count = 0, i;

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

        if(ctx->inputs[i]) {

            avfilter_formats_ref(formats, &ctx->inputs[i]->out_formats);

            count ++;

        }

    }

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

        if(ctx->outputs[i]) {

            avfilter_formats_ref(formats, &ctx->outputs[i]->in_formats);

            count ++;

        }

    }

    if(!count) {

        av_free(formats->formats);

        av_free(formats->refs);

        av_free(formats);

    }

}

int avfilter_default_query_formats(AVFilterContext *ctx)

{

    enum AVMediaType type = ctx->inputs [0] ? ctx->inputs [0]->type :

                            ctx->outputs[0] ? ctx->outputs[0]->type :

                            AVMEDIA_TYPE_VIDEO;

    avfilter_set_common_formats(ctx, avfilter_all_formats(type));

    return 0;

}

void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)

{

    avfilter_start_frame(link->dst->outputs[0], picref);

}

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

{

    avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);

}

void avfilter_null_end_frame(AVFilterLink *link)

{

    avfilter_end_frame(link->dst->outputs[0]);

}

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

{

    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);

}