IEC61937_MPEG1_LAYER1 46 libavformat/spdifdec.c case IEC61937_MPEG1_LAYER1: IEC61937_MPEG1_LAYER1 323 libavformat/spdifenc.c { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, //MPEG1