add the ability to set audio metadata on a buffer

gst/audio/gst_audio_meta.go

@@ -0,0 +1,31 @@
+package audio
+
+/*
+#include "gst.go.h"
+*/
+import "C"
+
+import (
+	"unsafe"
+
+	"github.com/tinyzimmer/go-gst/gst"
+)
+
+type AudioMeta struct {
+	ptr *C.GstAudioMeta
+}
+
+func wrapMetaFull(ptr *C.GstAudioMeta) *AudioMeta {
+	meta := &AudioMeta{ptr}
+	return meta
+}
+
+func BufferAddAudioMeta(buffer *gst.Buffer, info *Info, samples int64, offsets []int) *AudioMeta {
+	gSizeOffsets := C.gsize(unsafe.Sizeof(unsafe.Pointer(&offsets)))
+	return wrapMetaFull(C.gst_buffer_add_audio_meta(
+		(*C.GstBuffer)(unsafe.Pointer(buffer.Instance())),
+		info.ptr,
+		C.gsize(samples),
+		&gSizeOffsets,
+	))
+}

gst/audio/pkg_config.go

@@ -1,7 +1,7 @@
 package audio
 
 /*
-#cgo pkg-config: gstreamer-plugins-base-1.0
+#cgo pkg-config: gstreamer-plugins-base-1.0 gstreamer-audio-1.0
 #cgo CFLAGS: -Wno-deprecated-declarations
 #cgo LDFLAGS: -lgstaudio-1.0
 */

gst/video/pkg_config.go

@@ -1,7 +1,7 @@
 package video
 
 /*
-#cgo pkg-config: gstreamer-plugins-base-1.0
+#cgo pkg-config: gstreamer-plugins-base-1.0 gstreamer-video-1.0
 #cgo CFLAGS: -Wno-deprecated-declarations
 #cgo LDFLAGS: -lgstvideo-1.0
 */