pkg-config --cflags always puts you in the opus/ directory where opus.h
directly lives. No need to prefix with opus/. That just happened to work
because it was symlinked into /usr/include/opus, but we don't need to
rely on that now that we're using pkg-config.
Based on Tobias Wellnitz's comment (hraban/opus#12)
/*
#cgo pkg-config: opus
-#include <opus/opus.h>
+#include <opus.h>
*/
import "C"
/*
#cgo pkg-config: opus
-#include <opus/opus.h>
+#include <opus.h>
int
bridge_encoder_set_dtx(OpusEncoder *st, opus_int32 use_dtx)
/*
#cgo pkg-config: opus opusfile
-#include <opus/opus.h>
+#include <opus.h>
#include <opusfile.h>
// Access the preprocessor from CGO
/*
// Link opus using pkg-config.
#cgo pkg-config: opus
-#include <opus/opus.h>
+#include <opus.h>
// Access the preprocessor from CGO
const int CONST_APPLICATION_VOIP = OPUS_APPLICATION_VOIP;