2023-10-13 20:52:26 CST W41D5

ffmpeg_helper.go

@@ -0,0 +1,42 @@
+package ffmpeg
+
+/*
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"unsafe"
+)
+
+type HelperInteger interface {
+	HelperSingedInteger | HelperUnsingedInteger
+}
+
+type HelperSingedInteger interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64
+}
+
+type HelperUnsingedInteger interface {
+	~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+// StringCasting casts go string to c world char* with free function
+// Note: if input is a empty string will return a nil pointer.
+func StringCasting(str string) (allocPtr *C.char, freeFunc func()) {
+	if len(str) == 0 {
+		return nil, func() {}
+	}
+	allocPtr = C.CString(str)
+	freeFunc = func() { C.free(unsafe.Pointer(allocPtr)) }
+	return allocPtr, freeFunc
+}
+
+// SliceWithOffset returns a []byte slice from a porinter with size.
+func Slice[T HelperInteger](data *uint8, size T) []byte {
+	return unsafe.Slice(data, size)
+}
+
+// SliceWithOffset returns a []byte slice from a porinter with offset and size.
+func SliceWithOffset[U, V HelperInteger](data *uint8, offset U, size V) []byte {
+	return unsafe.Slice((*uint8)(unsafe.Add(unsafe.Pointer(uintptr(unsafe.Pointer(data))), offset)), size)
+}