| /* |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * FIFO buffering video filter |
| */ |
| |
| #include "avfilter.h" |
| |
| typedef struct BufPic { |
| AVFilterBufferRef *picref; |
| struct BufPic *next; |
| } BufPic; |
| |
| typedef struct { |
| BufPic root; |
| BufPic *last; ///< last buffered picture |
| } 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; |
| BufPic *pic, *tmp; |
| |
| for (pic = fifo->root.next; pic; pic = tmp) { |
| tmp = pic->next; |
| avfilter_unref_buffer(pic->picref); |
| av_free(pic); |
| } |
| } |
| |
| static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) |
| { |
| FifoContext *fifo = inlink->dst->priv; |
| |
| fifo->last->next = av_mallocz(sizeof(BufPic)); |
| fifo->last = fifo->last->next; |
| fifo->last->picref = picref; |
| } |
| |
| 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; |
| BufPic *tmp; |
| int ret; |
| |
| if (!fifo->root.next) { |
| if ((ret = avfilter_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. */ |
| avfilter_start_frame(outlink, fifo->root.next->picref); |
| avfilter_draw_slice (outlink, 0, outlink->h, 1); |
| avfilter_end_frame (outlink); |
| |
| 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 = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .get_video_buffer= avfilter_null_get_video_buffer, |
| .start_frame = start_frame, |
| .draw_slice = draw_slice, |
| .end_frame = end_frame, |
| .rej_perms = AV_PERM_REUSE2, }, |
| { .name = NULL}}, |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .request_frame = request_frame, }, |
| { .name = NULL}}, |
| }; |