add own libmpv binding

2023-02-18 12:36:15 -08:00
parent bc4a55e23a
commit 4297e3318a
1 changed files with 187 additions and 0 deletions
@@ -0,0 +1,187 @@
+package player
+
+/*
+#include <mpv/client.h>
+#include <stdlib.h>
+#cgo LDFLAGS: -lmpv
+
+char** newCharArray(int size) {
+    return calloc(sizeof(char*), size);
+}
+void setCharArrayIdx(char** a, int i, char* s) {
+    a[i] = s;
+}
+
+*/
+import "C"
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+)
+
+type MPVFormat int
+
+const (
+	MPVFormatDouble MPVFormat = C.MPV_FORMAT_DOUBLE
+	MPVFormatFlag   MPVFormat = C.MPV_FORMAT_FLAG
+	MPVFormatString MPVFormat = C.MPV_FORMAT_STRING
+	MPVFormatInt64  MPVFormat = C.MPV_FORMAT_INT64
+)
+
+type MPVEventID int
+
+const (
+	MPVEventNone            MPVEventID = C.MPV_EVENT_NONE
+	MPVEventStartFile       MPVEventID = C.MPV_EVENT_START_FILE
+	MPVEventEndFile         MPVEventID = C.MPV_EVENT_END_FILE
+	MPVEventFileLoaded      MPVEventID = C.MPV_EVENT_FILE_LOADED
+	MPVEventIdle            MPVEventID = C.MPV_EVENT_IDLE
+	MPVEventAudioReconfig   MPVEventID = C.MPV_EVENT_AUDIO_RECONFIG
+	MPVEventSeek            MPVEventID = C.MPV_EVENT_SEEK
+	MPVEventPlaybackRestart MPVEventID = C.MPV_EVENT_PLAYBACK_RESTART
+	MPVEventPropertyChange  MPVEventID = C.MPV_EVENT_PROPERTY_CHANGE
+)
+
+type MPVEvent struct {
+	ID       MPVEventID
+	ErrCode  int
+	Data     unsafe.Pointer
+	UserData uint64
+}
+
+type libmpv struct {
+	handle *C.mpv_handle
+}
+
+func CreateMPV() (libmpv, error) {
+	handle := C.mpv_create()
+	if handle == nil {
+		return libmpv{}, errors.New("failed to create mpv instance")
+	}
+	return libmpv{handle}, nil
+}
+
+func (m libmpv) Initialize() error {
+	return toMPVError(C.mpv_initialize(m.handle))
+}
+
+func (m libmpv) Command(cmd []string) error {
+	cArray := C.newCharArray(C.int(len(cmd) + 1))
+	if cArray == nil {
+		return errors.New("calloc failed")
+	}
+	defer C.free(unsafe.Pointer(cArray))
+
+	for i, s := range cmd {
+		cStr := C.CString(s)
+		C.setCharArrayIdx(cArray, C.int(i), cStr)
+		defer C.free(unsafe.Pointer(cStr))
+	}
+
+	return toMPVError(C.mpv_command(m.handle, cArray))
+}
+
+func (m libmpv) SetOption(name string, format MPVFormat, value any) error {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	p := toPointer(format, value)
+	return toMPVError(C.mpv_set_option(m.handle, cname, C.mpv_format(format), p))
+}
+
+func (m libmpv) SetOptionString(name, value string) error {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	cvalue := C.CString(value)
+	defer C.free(unsafe.Pointer(cvalue))
+	return toMPVError(C.mpv_set_option_string(m.handle, cname, cvalue))
+}
+
+func (m libmpv) SetProperty(name string, format MPVFormat, value any) error {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	p := toPointer(format, value)
+	return toMPVError(C.mpv_set_property(m.handle, cname, C.mpv_format(format), p))
+}
+
+func (m libmpv) GetProperty(name string, format MPVFormat) (any, error) {
+	cname := C.CString(name)
+	defer C.free(unsafe.Pointer(cname))
+	switch format {
+	case MPVFormatDouble:
+		var cdbl C.double
+		err := toMPVError(C.mpv_get_property(m.handle, cname, C.mpv_format(format), unsafe.Pointer(&cdbl)))
+		if err != nil {
+			return nil, err
+		}
+		return float64(cdbl), nil
+	case MPVFormatFlag:
+		var cint C.int
+		err := toMPVError(C.mpv_get_property(m.handle, cname, C.mpv_format(format), unsafe.Pointer(&cint)))
+		if err != nil {
+			return nil, err
+		}
+		return cint == 1, nil
+	case MPVFormatInt64:
+		var cint64 C.int64_t
+		err := toMPVError(C.mpv_get_property(m.handle, cname, C.mpv_format(format), unsafe.Pointer(&cint64)))
+		if err != nil {
+			return nil, err
+		}
+		return int64(cint64), nil
+	default:
+		return nil, errors.New("unsupported mpv format")
+	}
+}
+
+func (m libmpv) WaitEvent(timeout float64) MPVEvent {
+	var cevent *C.mpv_event
+	cevent = C.mpv_wait_event(m.handle, C.double(timeout))
+	if cevent == nil {
+		return MPVEvent{ID: MPVEventNone}
+	}
+
+	e := MPVEvent{
+		ID:       MPVEventID(cevent.event_id),
+		UserData: uint64(cevent.reply_userdata),
+		ErrCode:  int(cevent.error),
+		Data:     cevent.data,
+	}
+	return e
+}
+
+func (m libmpv) TerminateDestroy() {
+	C.mpv_terminate_destroy(m.handle)
+}
+
+func toMPVError(errcode C.int) error {
+	if errcode == C.MPV_ERROR_SUCCESS {
+		return nil
+	}
+	return fmt.Errorf("mpv error %d: %s", int(errcode), C.GoString(C.mpv_error_string(C.int(errcode))))
+}
+
+func toPointer(format MPVFormat, value any) unsafe.Pointer {
+	var ptr unsafe.Pointer = nil
+	switch format {
+	case MPVFormatDouble:
+		v := C.double(value.(float64))
+		ptr = unsafe.Pointer(&v)
+	case MPVFormatInt64:
+		i, ok := value.(int64)
+		if !ok {
+			i = int64(value.(int))
+		}
+		v := C.int64_t(i)
+		ptr = unsafe.Pointer(&v)
+	case MPVFormatFlag:
+		v := C.int(0)
+		if value.(bool) {
+			v = C.int(1)
+		}
+		ptr = unsafe.Pointer(&v)
+	case MPVFormatString:
+		ptr = unsafe.Pointer(&[]byte(value.(string))[0])
+	}
+	return ptr
+}