Files
mediadevices/pkg/driver/screen/x11capture_linux.go
2021-03-03 23:17:49 +09:00

325 lines
7.9 KiB
Go

package screen
// #cgo pkg-config: x11 xext
// #include <stdint.h>
// #include <string.h>
// #include <sys/shm.h>
// #include <X11/Xlib.h>
// #define XUTIL_DEFINE_FUNCTIONS
// #include <X11/Xutil.h>
// #include <X11/extensions/XShm.h>
//
// void copyBGR24(void *dst, char *src, size_t l) { // 64bit aligned copy
// uint64_t *d = (uint64_t*)dst;
// uint64_t *s = (uint64_t*)src;
// l /= 8;
// for (size_t i = 0; i < l; i ++) {
// uint64_t v = *s;
// // Reorder BGR to RGB
// *d = 0xFF000000FF000000 |
// ((v >> 16) & 0xFF00000000) | (v & 0xFF0000000000) | ((v & 0xFF00000000) << 16) |
// ((v >> 16) & 0xFF) | (v & 0xFF00) | ((v & 0xFF) << 16);
// d++;
// s++;
// }
// }
//
// void copyBGR16(void *dst, char *src, size_t l) { // 64bit aligned copy
// uint64_t *d = (uint64_t*)dst;
// uint32_t *s = (uint32_t*)src;
// l /= 8;
// for (size_t i = 0; i < l; i ++) {
// uint64_t v = *s;
// // Reorder BGR to RGB
// *d = 0xFF000000FF000000 |
// ((v & 0xF8000000) << 8) | ((v & 0x7E00000) << 21) | ((v & 0x1F0000) << 35) |
// ((v & 0xF800) >> 8) | ((v & 0x7E0) << 5) | ((v & 0x1F) << 19);
// d++;
// s++;
// }
// }
//
// char *align64(char *ptr) { // return 64bit aligned pointer
// if (((size_t)ptr & 0x07) == 0) {
// return ptr;
// }
// // Clear lower 3bits to align the address to 8bytes.
// return (char*)(((size_t)ptr & (~(size_t)0x07)) + 0x08);
// }
// size_t align64ForTest(size_t ptr) {
// return (size_t)align64((char*)ptr);
// }
import "C"
import (
"errors"
"fmt"
"image"
"image/color"
"unsafe"
)
const shmaddrInvalid = ^uintptr(0)
type display C.Display
type pixelFormat int
const (
pixFmtBGR24 pixelFormat = iota
pixFmtRGB24
pixFmtBGR16
pixFmtRGB16
)
func openDisplay() (*display, error) {
dp := C.XOpenDisplay(nil)
if dp == nil {
return nil, errors.New("failed to open display")
}
return (*display)(dp), nil
}
func (d *display) c() *C.Display {
return (*C.Display)(d)
}
func (d *display) Close() {
C.XCloseDisplay(d.c())
}
func (d *display) NumScreen() int {
return int(C.XScreenCount(d.c()))
}
type shmImage struct {
dp *C.Display
img *C.XImage
shm C.XShmSegmentInfo
b []byte
pixFmt pixelFormat
}
func (s *shmImage) Free() {
if s.img != nil {
C.XShmDetach(s.dp, &s.shm)
C.XDestroyImage(s.img)
}
if uintptr(unsafe.Pointer(s.shm.shmaddr)) != shmaddrInvalid {
C.shmdt(unsafe.Pointer(s.shm.shmaddr))
}
}
func (s *shmImage) ColorModel() color.Model {
return color.RGBAModel
}
func (s *shmImage) Bounds() image.Rectangle {
return image.Rect(0, 0, int(s.img.width), int(s.img.height))
}
type colorFunc func() (r, g, b, a uint32)
func (c colorFunc) RGBA() (r, g, b, a uint32) {
return c()
}
func (s *shmImage) At(x, y int) color.Color {
switch s.pixFmt {
case pixFmtRGB24:
addr := (x + y*int(s.img.width)) * 4
r := uint32(s.b[addr]) * 0x100
g := uint32(s.b[addr+1]) * 0x100
b := uint32(s.b[addr+2]) * 0x100
return colorFunc(func() (_, _, _, _ uint32) {
return r, g, b, 0xFFFF
})
case pixFmtBGR24:
addr := (x + y*int(s.img.width)) * 4
b := uint32(s.b[addr]) * 0x100
g := uint32(s.b[addr+1]) * 0x100
r := uint32(s.b[addr+2]) * 0x100
return colorFunc(func() (_, _, _, _ uint32) {
return r, g, b, 0xFFFF
})
case pixFmtRGB16:
addr := (x + y*int(s.img.width)) * 2
b1, b2 := s.b[addr], s.b[addr+1]
r := uint32(b1>>3) * 0x100
g := uint32((b1&0x7)<<3|(b2&0xE0)>>5) * 0x100
b := uint32(b2&0x1F) * 0x100
return colorFunc(func() (_, _, _, _ uint32) {
return r, g, b, 0xFFFF
})
case pixFmtBGR16:
addr := (x + y*int(s.img.width)) * 2
b1, b2 := s.b[addr], s.b[addr+1]
b := uint32(b1>>3) * 0x100
g := uint32((b1&0x7)<<3|(b2&0xE0)>>5) * 0x100
r := uint32(b2&0x1F) * 0x100
return colorFunc(func() (_, _, _, _ uint32) {
return r, g, b, 0xFFFF
})
default:
panic("unsupported pixel format")
}
}
func (s *shmImage) RGBAAt(x, y int) color.RGBA {
switch s.pixFmt {
case pixFmtRGB24:
addr := (x + y*int(s.img.width)) * 4
r := s.b[addr]
g := s.b[addr+1]
b := s.b[addr+2]
return color.RGBA{R: r, G: g, B: b, A: 0xFF}
case pixFmtBGR24:
addr := (x + y*int(s.img.width)) * 4
b := s.b[addr]
g := s.b[addr+1]
r := s.b[addr+2]
return color.RGBA{R: r, G: g, B: b, A: 0xFF}
case pixFmtRGB16:
addr := (x + y*int(s.img.width)) * 2
b1, b2 := s.b[addr], s.b[addr+1]
r := b1 >> 3
g := (b1&0x7)<<3 | (b2&0xE0)>>5
b := b2 & 0x1F
return color.RGBA{R: r, G: g, B: b, A: 0xFF}
case pixFmtBGR16:
addr := (x + y*int(s.img.width)) * 2
b1, b2 := s.b[addr], s.b[addr+1]
b := b1 >> 3
g := (b1&0x7)<<3 | (b2&0xE0)>>5
r := b2 & 0x1F
return color.RGBA{R: r, G: g, B: b, A: 0xFF}
default:
panic("unsupported pixel format")
}
}
func (s *shmImage) ToRGBA(dst *image.RGBA) *image.RGBA {
dst.Rect = s.Bounds()
dst.Stride = int(s.img.width) * 4
l := int(4 * s.img.width * s.img.height)
if len(dst.Pix) < l {
if cap(dst.Pix) < l {
dst.Pix = make([]uint8, l)
}
dst.Pix = dst.Pix[:l]
}
switch s.pixFmt {
case pixFmtRGB24:
C.memcpy(unsafe.Pointer(&dst.Pix[0]), unsafe.Pointer(s.img.data), C.size_t(len(dst.Pix)))
return dst
case pixFmtBGR24:
C.copyBGR24(unsafe.Pointer(&dst.Pix[0]), s.img.data, C.size_t(len(dst.Pix)))
return dst
case pixFmtRGB16:
C.memcpy(unsafe.Pointer(&dst.Pix[0]), unsafe.Pointer(s.img.data), C.size_t(len(dst.Pix)))
return dst
case pixFmtBGR16:
C.copyBGR16(unsafe.Pointer(&dst.Pix[0]), s.img.data, C.size_t(len(dst.Pix)))
return dst
default:
panic("unsupported pixel format")
}
}
func newShmImage(dp *C.Display, screen int) (*shmImage, error) {
cScreen := C.int(screen)
w := int(C.XDisplayWidth(dp, cScreen))
h := int(C.XDisplayHeight(dp, cScreen))
v := C.XDefaultVisual(dp, cScreen)
depth := int(C.XDefaultDepth(dp, cScreen))
s := &shmImage{dp: dp}
switch {
case v.red_mask == 0xFF && v.green_mask == 0xFF00 && v.blue_mask == 0xFF0000:
s.pixFmt = pixFmtRGB24
case v.red_mask == 0xFF0000 && v.green_mask == 0xFF00 && v.blue_mask == 0xFF:
s.pixFmt = pixFmtBGR24
case v.red_mask == 0x1F && v.green_mask == 0x7E0 && v.blue_mask == 0xF800:
s.pixFmt = pixFmtRGB16
case v.red_mask == 0xF800 && v.green_mask == 0x7E0 && v.blue_mask == 0x1F:
s.pixFmt = pixFmtBGR16
default:
fmt.Printf("x11capture: unsupported pixel format (R: %0x, G: %0x, B: %0x)\n",
v.red_mask, v.green_mask, v.blue_mask)
return nil, errors.New("unsupported pixel format")
}
s.shm.shmid = C.shmget(C.IPC_PRIVATE, C.size_t(w*h*4+8), C.IPC_CREAT|0600)
if s.shm.shmid == -1 {
return nil, errors.New("failed to get shared memory")
}
s.shm.shmaddr = (*C.char)(C.shmat(s.shm.shmid, unsafe.Pointer(nil), 0))
if uintptr(unsafe.Pointer(s.shm.shmaddr)) == shmaddrInvalid {
s.shm.shmaddr = nil
return nil, errors.New("failed to get shared memory address")
}
s.shm.readOnly = 0
C.shmctl(s.shm.shmid, C.IPC_RMID, nil)
s.img = C.XShmCreateImage(
dp, v, C.uint(depth), C.ZPixmap, C.align64(s.shm.shmaddr), &s.shm, C.uint(w), C.uint(h))
if s.img == nil {
s.Free()
return nil, errors.New("failed to create XShm image")
}
C.XShmAttach(dp, &s.shm)
C.XSync(dp, 0)
return s, nil
}
type reader struct {
dp *C.Display
img *shmImage
}
func newReader(screen int) (*reader, error) {
dp := C.XOpenDisplay(nil)
if dp == nil {
return nil, errors.New("failed to open display")
}
if C.XShmQueryExtension(dp) == 0 {
return nil, errors.New("no XShm support")
}
img, err := newShmImage(dp, screen)
if err != nil {
C.XCloseDisplay(dp)
return nil, err
}
return &reader{
dp: dp,
img: img,
}, nil
}
func (r *reader) Size() (int, int) {
return int(r.img.img.width), int(r.img.img.height)
}
func (r *reader) Read() *shmImage {
C.XShmGetImage(r.dp, C.XDefaultRootWindow(r.dp), r.img.img, 0, 0, C.AllPlanes)
r.img.b = C.GoBytes(
unsafe.Pointer(r.img.img.data),
C.int(r.img.img.width*r.img.img.height*4),
)
return r.img
}
func (r *reader) Close() {
r.img.Free()
C.XCloseDisplay(r.dp)
}
// cAlign64 is fot testing
func cAlign64(ptr uintptr) uintptr {
return uintptr(C.align64ForTest(C.size_t(uintptr(ptr))))
}