/*
  * 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 "dualinput.h"
 #include "libavutil/timestamp.h"
 

 static int process_frame(FFFrameSync *fs)

 {

     AVFilterContext *ctx = fs->parent;
     FFDualInputContext *s = fs->opaque;
     AVFrame *mainpic = NULL, *secondpic = NULL;
     int ret = 0;
 
     if ((ret = ff_framesync_get_frame(&s->fs, 0, &mainpic,   1)) < 0 ||
         (ret = ff_framesync_get_frame(&s->fs, 1, &secondpic, 0)) < 0) {
         av_frame_free(&mainpic);
         return ret;

     }

     av_assert0(mainpic);
     mainpic->pts = av_rescale_q(mainpic->pts, s->fs.time_base, ctx->outputs[0]->time_base);
     if (secondpic && !ctx->is_disabled)
         mainpic = s->process(ctx, mainpic, secondpic);

     ret = ff_filter_frame(ctx->outputs[0], mainpic);
     av_assert1(ret != AVERROR(EAGAIN));
     return ret;
 }
 

 int ff_dualinput_init(AVFilterContext *ctx, FFDualInputContext *s)

 {

     FFFrameSyncIn *in = s->fs.in;
 
     ff_framesync_init(&s->fs, ctx, 2);
     s->fs.opaque = s;
     s->fs.on_event = process_frame;
     in[0].time_base = ctx->inputs[0]->time_base;
     in[1].time_base = ctx->inputs[1]->time_base;
     in[0].sync   = 2;
     in[0].before = EXT_STOP;
     in[0].after  = EXT_INFINITY;
     in[1].sync   = 1;
     in[1].before = EXT_NULL;
     in[1].after  = EXT_INFINITY;
 
     if (s->shortest)

         in[0].after = in[1].after = EXT_STOP;

     if (!s->repeatlast) {

         in[1].after = EXT_NULL;

         in[1].sync  = 0;
     }

     return ff_framesync_configure(&s->fs);

 }
 

 int ff_dualinput_filter_frame(FFDualInputContext *s,

                                    AVFilterLink *inlink, AVFrame *in)
 {

     return ff_framesync_filter_frame(&s->fs, inlink, in);

 }
 
 int ff_dualinput_request_frame(FFDualInputContext *s, AVFilterLink *outlink)
 {

     return ff_framesync_request_frame(&s->fs, outlink);

 }
 
 void ff_dualinput_uninit(FFDualInputContext *s)
 {

     ff_framesync_uninit(&s->fs);

 }