MAKE_ACCESSORS(AVCodecContext, codec, AVRational, pkt_timebase)
MAKE_ACCESSORS(AVCodecContext, codec, const AVCodecDescriptor *, codec_descriptor)
MAKE_ACCESSORS(AVCodecContext, codec, int, lowres)
MAKE_ACCESSORS(AVCodecContext, codec, int, seek_preroll)
MAKE_ACCESSORS(AVCodecContext, codec, uint16_t*, chroma_intra_matrix)

unsigned av_codec_get_codec_properties(const AVCodecContext *codec)
{
    return codec->properties;
}

The product writes data past the end, or before the beginning, of the intended buffer.