/* * Copyright (c) 2007 Bobby Bingham * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * FIFO buffering filter */ #include "audio.h"#include "avfilter.h"#include "internal.h"#include "video.h" typedef struct Buf {    AVFilterBufferRef *buf;    struct Buf        *next;} Buf; typedef struct {    Buf  root;    Buf *last;   ///< last buffered frame} FifoContext; static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque){    FifoContext *fifo = ctx->priv;    fifo->last = &fifo->root;     av_log(ctx, AV_LOG_INFO, "\n");    return 0;} static av_cold void uninit(AVFilterContext *ctx){    FifoContext *fifo = ctx->priv;    Buf *buf, *tmp;     for (buf = fifo->root.next; buf; buf = tmp) {        tmp = buf->next;        avfilter_unref_buffer(buf->buf);        av_free(buf);    }} static void add_to_queue(AVFilterLink *inlink, AVFilterBufferRef *buf){    FifoContext *fifo = inlink->dst->priv;     fifo->last->next = av_mallocz(sizeof(Buf));    fifo->last = fifo->last->next;    fifo->last->buf = buf;} static void end_frame(AVFilterLink *inlink) { } static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { } static int request_frame(AVFilterLink *outlink){    FifoContext *fifo = outlink->src->priv;    Buf *tmp;    int ret;     if (!fifo->root.next) {        if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0)            return ret;    }     /* by doing this, we give ownership of the reference to the next filter,     * so we don't have to worry about dereferencing it ourselves. */    switch (outlink->type) {    case AVMEDIA_TYPE_VIDEO:        ff_start_frame(outlink, fifo->root.next->buf);        ff_draw_slice (outlink, 0, outlink->h, 1);        ff_end_frame  (outlink);        break;    case AVMEDIA_TYPE_AUDIO:        ff_filter_samples(outlink, fifo->root.next->buf);        break;    default:        return AVERROR(EINVAL);    }     if (fifo->last == fifo->root.next)        fifo->last = &fifo->root;    tmp = fifo->root.next->next;    av_free(fifo->root.next);    fifo->root.next = tmp;     return 0;} AVFilter avfilter_vf_fifo = {    .name      = "fifo",    .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),     .init      = init,    .uninit    = uninit,     .priv_size = sizeof(FifoContext),     .inputs    = (AVFilterPad[]) {{ .name            = "default",                                    .type            = AVMEDIA_TYPE_VIDEO,                                    .get_video_buffer= ff_null_get_video_buffer,                                    .start_frame     = add_to_queue,                                    .draw_slice      = draw_slice,                                    .end_frame       = end_frame,                                    .rej_perms       = AV_PERM_REUSE2, },                                  { .name = NULL}},    .outputs   = (AVFilterPad[]) {{ .name            = "default",                                    .type            = AVMEDIA_TYPE_VIDEO,                                    .request_frame   = request_frame, },                                  { .name = NULL}},}; AVFilter avfilter_af_afifo = {    .name        = "afifo",    .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),     .init      = init,    .uninit    = uninit,     .priv_size = sizeof(FifoContext),     .inputs    = (AVFilterPad[]) {{ .name             = "default",                                    .type             = AVMEDIA_TYPE_AUDIO,                                    .get_audio_buffer = ff_null_get_audio_buffer,                                    .filter_samples   = add_to_queue,                                    .rej_perms        = AV_PERM_REUSE2, },                                  { .name = NULL}},    .outputs   = (AVFilterPad[]) {{ .name             = "default",                                    .type             = AVMEDIA_TYPE_AUDIO,                                    .request_frame    = request_frame, },                                  { .name = NULL}},};