from av.audio.stream cimport AudioStream cdef extern from "libavcodec/avcodec.h": ctypedef struct AVCodecContext: pass cdef extern from "libavformat/avformat.h": ctypedef struct AVFormatContext: pass cdef extern from "loudnorm_impl.h": char* loudnorm_get_stats( AVFormatContext* fmt_ctx, int audio_stream_index, const char* loudnorm_args ) nogil cpdef bytes stats(str loudnorm_args, AudioStream stream)