Add avdevice support (#29)

* Add avdevice support

* Format Adjustment:
DeviceRegisterAll renamed to RegisterAllDevices
Move FindInputFormat position
Add Name(), LongName(), String() methods to InputFormat
Adjust TestInputFormat test

device.go

@@ -0,0 +1,9 @@
+package astiav
+
+//#cgo pkg-config: libavdevice
+//#include <libavdevice/avdevice.h>
+import "C"
+
+func RegisterAllDevices() {
+	C.avdevice_register_all()
+}

device_test.go

@@ -0,0 +1,10 @@
+package astiav_test
+
+import (
+	"github.com/asticode/go-astiav"
+	"testing"
+)
+
+func TestDevice(t *testing.T) {
+	astiav.RegisterAllDevices()
+}

input_format.go

@@ -3,6 +3,7 @@ package astiav
 //#cgo pkg-config: libavformat
 //#include <libavformat/avformat.h>
 import "C"
+import "unsafe"
 
 // https://github.com/FFmpeg/FFmpeg/blob/n5.0/libavformat/avformat.h#L650
 type InputFormat struct {
@@ -16,6 +17,25 @@ func newInputFormatFromC(c *C.struct_AVInputFormat) *InputFormat {
 	return &InputFormat{c: c}
 }
 
+func FindInputFormat(name string) *InputFormat {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	return newInputFormatFromC(C.av_find_input_format(cname))
+}
+
 func (f *InputFormat) Flags() IOFormatFlags {
 	return IOFormatFlags(f.c.flags)
 }
+
+func (f *InputFormat) Name() string {
+	return C.GoString(f.c.name)
+}
+
+// LongName Description of the format, meant to be more human-readable than Name.
+func (f *InputFormat) LongName() string {
+	return C.GoString(f.c.long_name)
+}
+
+func (f *InputFormat) String() string {
+	return f.Name()
+}

input_format_test.go

@@ -0,0 +1,14 @@
+package astiav_test
+
+import (
+	"github.com/asticode/go-astiav"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestInputFormat(t *testing.T) {
+	formatName := "rawvideo"
+	inputFormat := astiav.FindInputFormat(formatName)
+	require.NotNil(t, inputFormat)
+	require.True(t, inputFormat.Name() == formatName)
+}