AVDurationEstimationMethod 1724 libavformat/avformat.h     enum AVDurationEstimationMethod duration_estimation_method;
AVDurationEstimationMethod 2008 libavformat/avformat.h enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
AVDurationEstimationMethod  165 libavformat/options.c enum AVDurationEstimationMethod av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx)
AVDurationEstimationMethod 2942 libavformat/utils.c static const char *duration_estimate_name(enum AVDurationEstimationMethod method)