av_guess_frame_rate  648 ffmpeg_filter.c         fr = av_guess_frame_rate(input_files[ist->file_index]->ctx, ist->st, NULL);
av_guess_frame_rate 1965 ffplay.c           AVRational fr = av_guess_frame_rate(is->ic, is->video_st, NULL);
av_guess_frame_rate 2224 ffplay.c           AVRational frame_rate = av_guess_frame_rate(is->ic, is->video_st, NULL);
av_guess_frame_rate 2650 libavformat/avformat.h AVRational av_guess_frame_rate(AVFormatContext *ctx, AVStream *stream, AVFrame *frame);