@@ -1760,6 +1760,7 @@ static int configure_video_filters(AVFilterGraph *graph, VideoState *is, const c

     AVBufferSinkParams *buffersink_params = av_buffersink_params_alloc();

     AVFilterContext *filt_src = NULL, *filt_out = NULL, *filt_crop;

     AVCodecContext *codec = is->video_st->codec;

+    AVRational fr = av_guess_frame_rate(is->ic, is->video_st, NULL);

     if (!buffersink_params)

         return AVERROR(ENOMEM);

@@ -1773,6 +1774,8 @@ static int configure_video_filters(AVFilterGraph *graph, VideoState *is, const c

              frame->width, frame->height, frame->format,

              is->video_st->time_base.num, is->video_st->time_base.den,

              codec->sample_aspect_ratio.num, FFMAX(codec->sample_aspect_ratio.den, 1));

+    if (fr.num && fr.den)

+        av_strlcatf(buffersrc_args, sizeof(buffersrc_args), ":frame_rate=%d/%d", fr.num, fr.den);

     if ((ret = avfilter_graph_create_filter(&filt_src,

                                             avfilter_get_by_name("buffer"),