proc av_get_audio_frame_duration2(par: ptr AVCodecParameters; frame_bytes: cint): cint {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}

proc avcodec_parameters_alloc(): ptr AVCodecParameters {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}

proc avcodec_parameters_copy(dst, src: ptr AVCodecParameters): cint {.importc,
    cdecl, ...raises: [], tags: [], forbids: [].}

proc avcodec_parameters_free(par: ptr ptr AVCodecParameters) {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}