}
#endif
-int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)
+uint64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)
{
switch(nb_channels) {
case 1: return AV_CH_LAYOUT_MONO;