/*
  * Copyright (c) 2011 Stefano Sabatini
  *
  * 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
  * buffer video sink
  */
 
 #include "avfilter.h"
 #include "vsink_buffer.h"
 
 typedef struct {
     AVFilterBufferRef *picref;   ///< cached picref
     enum PixelFormat *pix_fmts;  ///< accepted pixel formats, must be terminated with -1
 } BufferSinkContext;
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     BufferSinkContext *buf = ctx->priv;
 
     if (!opaque) {
         av_log(ctx, AV_LOG_ERROR, "No opaque field provided, which is required.\n");
         return AVERROR(EINVAL);
     }
 
     buf->pix_fmts = opaque;
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     BufferSinkContext *buf = ctx->priv;
 
     if (buf->picref)
         avfilter_unref_buffer(buf->picref);
     buf->picref = NULL;
 }
 
 static void end_frame(AVFilterLink *inlink)
 {
     BufferSinkContext *buf = inlink->dst->priv;
 
     if (buf->picref)            /* drop the last cached frame */
         avfilter_unref_buffer(buf->picref);
     buf->picref = inlink->cur_buf;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     BufferSinkContext *buf = ctx->priv;
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(buf->pix_fmts));

     return 0;
 }
 
 int av_vsink_buffer_get_video_buffer_ref(AVFilterContext *ctx,
                                          AVFilterBufferRef **picref, int flags)
 {
     BufferSinkContext *buf = ctx->priv;
     AVFilterLink *inlink = ctx->inputs[0];
     int ret;
     *picref = NULL;
 
     /* no picref available, fetch it from the filterchain */
     if (!buf->picref) {
         if ((ret = avfilter_request_frame(inlink)) < 0)
             return ret;
     }
 
     if (!buf->picref)
         return AVERROR(EINVAL);
 
     *picref = buf->picref;
     if (!(flags & AV_VSINK_BUF_FLAG_PEEK))
         buf->picref = NULL;
 
     return 0;
 }
 
 AVFilter avfilter_vsink_buffersink = {
     .name      = "buffersink",
     .priv_size = sizeof(BufferSinkContext),
     .init      = init,
     .uninit    = uninit,
 
     .query_formats = query_formats,
 
     .inputs    = (AVFilterPad[]) {{ .name          = "default",
                                     .type          = AVMEDIA_TYPE_VIDEO,
                                     .end_frame     = end_frame,
                                     .min_perms     = AV_PERM_READ, },
                                   { .name = NULL }},
     .outputs   = (AVFilterPad[]) {{ .name = NULL }},
 };