ff_decklink_set_format  101 libavdevice/decklink_common.cpp int ff_decklink_set_format(AVFormatContext *avctx,
ff_decklink_set_format  176 libavdevice/decklink_common.cpp int ff_decklink_set_format(AVFormatContext *avctx, decklink_direction_t direction, int num) {