1 /*
2 * GDI video grab interface
3 *
4 * This file is part of FFmpeg.
5 *
6 * Copyright (C) 2013 Calvin Walton <calvin.walton@kepstin.ca>
7 * Copyright (C) 2007-2010 Christophe Gisquet <word1.word2@gmail.com>
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public License
11 * as published by the Free Software Foundation; either version 2.1
12 * of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file
26 * GDI frame device demuxer
27 * @author Calvin Walton <calvin.walton@kepstin.ca>
28 * @author Christophe Gisquet <word1.word2@gmail.com>
29 */
30
31 #include "config.h"
35 #include <windows.h>
36
37 /**
38 * GDI Device Demuxer context
39 */
41 const AVClass *
class;
/**< Class for private options */
42
43 int frame_size;
/**< Size in bytes of the frame pixel data */
47
48 int draw_mouse;
/**< Draw mouse cursor (private option) */
51 int width;
/**< Width of the grab frame (private option) */
52 int height;
/**< Height of the grab frame (private option) */
53 int offset_x;
/**< Capture x offset (private option) */
54 int offset_y;
/**< Capture y offset (private option) */
55
56 HWND hwnd;
/**< Handle of the window for the grab */
59 BITMAPINFO
bmi;
/**< Information describing DIB format */
61 void *
buffer;
/**< The buffer containing the bitmap image data */
62 RECT
clip_rect;
/**< The subarea of the screen or window to clip */
63
65
67 };
68
69 #define WIN32_API_ERROR(str) \
70 av_log(s1, AV_LOG_ERROR, str " (error %li)\n", GetLastError())
71
72 #define REGION_WND_BORDER 3
73
74 /**
75 * Callback to handle Windows messages for the region outline window.
76 *
77 * In particular, this handles painting the frame rectangle.
78 *
79 * @param hwnd The region outline window handle.
80 * @param msg The Windows message.
81 * @param wparam First Windows message parameter.
82 * @param lparam Second Windows message parameter.
83 * @return 0 success, !0 failure
84 */
87 {
88 PAINTSTRUCT ps;
91
92 switch (msg) {
93 case WM_PAINT:
94 hdc = BeginPaint(hwnd, &ps);
95
96 GetClientRect(hwnd, &rect);
97 FrameRect(hdc, &rect, GetStockObject(BLACK_BRUSH));
98
99 rect.left++; rect.top++; rect.right--; rect.bottom--;
100 FrameRect(hdc, &rect, GetStockObject(WHITE_BRUSH));
101
102 rect.left++; rect.top++; rect.right--; rect.bottom--;
103 FrameRect(hdc, &rect, GetStockObject(BLACK_BRUSH));
104
105 EndPaint(hwnd, &ps);
106 break;
107 default:
108 return DefWindowProc(hwnd, msg, wparam, lparam);
109 }
110 return 0;
111 }
112
113 /**
114 * Initialize the region outline window.
115 *
116 * @param s1 The format context.
117 * @param gdigrab gdigrab context.
118 * @return 0 success, !0 failure
119 */
120 static int
122 {
125 HRGN region = NULL;
126 HRGN region_interior = NULL;
127
128 DWORD style = WS_POPUP | WS_VISIBLE;
129 DWORD ex = WS_EX_TOOLWINDOW | WS_EX_TOPMOST | WS_EX_TRANSPARENT;
130
133
134 AdjustWindowRectEx(&rect, style,
FALSE, ex);
135
136 // Create a window with no owner; use WC_DIALOG instead of writing a custom
137 // window class
138 hwnd = CreateWindowEx(ex, WC_DIALOG, NULL, style, rect.left, rect.top,
139 rect.right - rect.left, rect.bottom - rect.top,
140 NULL, NULL, NULL, NULL);
141 if (!hwnd) {
143 goto error;
144 }
145
146 // Set the window shape to only include the border area
147 GetClientRect(hwnd, &rect);
148 region = CreateRectRgn(0, 0,
149 rect.right - rect.left, rect.bottom - rect.top);
153 CombineRgn(region, region, region_interior, RGN_DIFF);
154 if (!SetWindowRgn(hwnd, region,
FALSE)) {
156 goto error;
157 }
158 // The "region" memory is now owned by the window
159 region = NULL;
160 DeleteObject(region_interior);
161
163
164 ShowWindow(hwnd, SW_SHOW);
165
167
168 return 0;
169
170 error:
171 if (region)
172 DeleteObject(region);
173 if (region_interior)
174 DeleteObject(region_interior);
175 if (hwnd)
176 DestroyWindow(hwnd);
177 return 1;
178 }
179
180 /**
181 * Cleanup/free the region outline window.
182 *
183 * @param s1 The format context.
184 * @param gdigrab gdigrab context.
185 */
186 static void
188 {
192 }
193
194 /**
195 * Process the Windows message queue.
196 *
197 * This is important to prevent Windows from thinking the window has become
198 * unresponsive. As well, things like WM_PAINT (to actually draw the window
199 * contents) are handled from the message queue context.
200 *
201 * @param s1 The format context.
202 * @param gdigrab gdigrab context.
203 */
204 static void
206 {
208 MSG msg;
209
210 while (PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE)) {
211 DispatchMessage(&msg);
212 }
213 }
214
215 /**
216 * Initializes the gdi grab device demuxer (public device demuxer API).
217 *
218 * @param s1 Context from avformat core
219 * @return AVERROR_IO error, 0 success
220 */
221 static int
223 {
225
232
233 const char *filename = s1->
filename;
234 const char *
name = NULL;
236
237 int bpp;
238 RECT virtual_rect;
240 BITMAP bmp;
242
243 if (!strncmp(filename, "title=", 6)) {
244 name = filename + 6;
245 hwnd = FindWindow(NULL, name);
246 if (!hwnd) {
248 "Can't find window '%s', aborting.\n", name);
250 goto error;
251 }
254 "Can't show region when grabbing a window.\n");
256 }
257 } else if (!strcmp(filename, "desktop")) {
258 hwnd = NULL;
259 } else {
261 "Please use \"desktop\" or \"title=<windowname>\" to specify your target.\n");
263 goto error;
264 }
265
266 if (hwnd) {
267 GetClientRect(hwnd, &virtual_rect);
268 } else {
269 virtual_rect.left = GetSystemMetrics(SM_XVIRTUALSCREEN);
270 virtual_rect.top = GetSystemMetrics(SM_YVIRTUALSCREEN);
271 virtual_rect.right = virtual_rect.left + GetSystemMetrics(SM_CXVIRTUALSCREEN);
272 virtual_rect.bottom = virtual_rect.top + GetSystemMetrics(SM_CYVIRTUALSCREEN);
273 }
274
275 /* If no width or height set, use full screen/window area */
277 clip_rect.left = virtual_rect.left;
278 clip_rect.top = virtual_rect.top;
279 clip_rect.right = virtual_rect.right;
280 clip_rect.bottom = virtual_rect.bottom;
281 } else {
286 }
287
288 if (clip_rect.left < virtual_rect.left ||
289 clip_rect.top < virtual_rect.top ||
290 clip_rect.right > virtual_rect.right ||
291 clip_rect.bottom > virtual_rect.bottom) {
293 "Capture area (%li,%li),(%li,%li) extends outside window area (%li,%li),(%li,%li)",
294 clip_rect.left, clip_rect.top,
295 clip_rect.right, clip_rect.bottom,
296 virtual_rect.left, virtual_rect.top,
297 virtual_rect.right, virtual_rect.bottom);
299 goto error;
300 }
301
302 /* This will get the device context for the selected window, or if
303 * none, the primary screen */
304 source_hdc = GetDC(hwnd);
305 if (!source_hdc) {
308 goto error;
309 }
310 bpp = GetDeviceCaps(source_hdc, BITSPIXEL);
311
312 if (name) {
314 "Found window %s, capturing %lix%lix%i at (%li,%li)\n",
315 name,
316 clip_rect.right - clip_rect.left,
317 clip_rect.bottom - clip_rect.top,
318 bpp, clip_rect.left, clip_rect.top);
319 } else {
321 "Capturing whole desktop as %lix%lix%i at (%li,%li)\n",
322 clip_rect.right - clip_rect.left,
323 clip_rect.bottom - clip_rect.top,
324 bpp, clip_rect.left, clip_rect.top);
325 }
326
327 if (clip_rect.right - clip_rect.left <= 0 ||
328 clip_rect.bottom - clip_rect.top <= 0 || bpp%8) {
331 goto error;
332 }
333
334 dest_hdc = CreateCompatibleDC(source_hdc);
335 if (!dest_hdc) {
338 goto error;
339 }
340
341 /* Create a DIB and select it into the dest_hdc */
342 bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
343 bmi.bmiHeader.biWidth = clip_rect.right - clip_rect.left;
344 bmi.bmiHeader.biHeight = -(clip_rect.bottom - clip_rect.top);
345 bmi.bmiHeader.biPlanes = 1;
346 bmi.bmiHeader.biBitCount = bpp;
347 bmi.bmiHeader.biCompression = BI_RGB;
348 bmi.bmiHeader.biSizeImage = 0;
349 bmi.bmiHeader.biXPelsPerMeter = 0;
350 bmi.bmiHeader.biYPelsPerMeter = 0;
351 bmi.bmiHeader.biClrUsed = 0;
352 bmi.bmiHeader.biClrImportant = 0;
353 hbmp = CreateDIBSection(dest_hdc, &bmi, DIB_RGB_COLORS,
354 &buffer, NULL, 0);
355 if (!hbmp) {
358 goto error;
359 }
360
361 if (!SelectObject(dest_hdc, hbmp)) {
364 goto error;
365 }
366
367 /* Get info from the bitmap */
368 GetObject(hbmp, sizeof(BITMAP), &bmp);
369
371 if (!st) {
373 goto error;
374 }
376
377 gdigrab->
frame_size = bmp.bmWidthBytes * bmp.bmHeight * bmp.bmPlanes;
378 gdigrab->
header_size =
sizeof(BITMAPFILEHEADER) +
sizeof(BITMAPINFOHEADER) +
379 (bpp <= 8 ? (1 << bpp) : 0) * sizeof(RGBQUAD) /* palette size */;
382
390
392
396 goto error;
397 }
398 }
399
404
405 return 0;
406
407 error:
408 if (source_hdc)
409 ReleaseDC(hwnd, source_hdc);
410 if (dest_hdc)
411 DeleteDC(dest_hdc);
412 if (hbmp)
413 DeleteObject(hbmp);
414 if (source_hdc)
415 DeleteDC(source_hdc);
417 }
418
419 /**
420 * Paints a mouse pointer in a Win32 image.
421 *
422 * @param s1 Context of the log information
423 * @param s Current grad structure
424 */
426 {
427 CURSORINFO ci = {0};
428
429 #define CURSOR_ERROR(str) \
430 if (!gdigrab->cursor_error_printed) { \
431 WIN32_API_ERROR(str); \
432 gdigrab->cursor_error_printed = 1; \
433 }
434
435 ci.cbSize = sizeof(ci);
436
437 if (GetCursorInfo(&ci)) {
438 HCURSOR icon = CopyCursor(ci.hCursor);
439 ICONINFO info;
440 POINT pos;
443
444 if (ci.flags != CURSOR_SHOWING)
445 return;
446
447 if (!icon) {
448 /* Use the standard arrow cursor as a fallback.
449 * You'll probably only hit this in Wine, which can't fetch
450 * the current system cursor. */
451 icon = CopyCursor(LoadCursor(NULL, IDC_ARROW));
452 }
453
454 if (!GetIconInfo(icon, &info)) {
456 goto icon_error;
457 }
458
459 pos.x = ci.ptScreenPos.x - clip_rect.left - info.xHotspot;
460 pos.y = ci.ptScreenPos.y - clip_rect.top - info.yHotspot;
461
462 if (hwnd) {
464
465 if (GetWindowRect(hwnd, &rect)) {
467 pos.y -= rect.top;
468 } else {
470 goto icon_error;
471 }
472 }
473
475 ci.ptScreenPos.x, ci.ptScreenPos.y, pos.x, pos.y);
476
477 if (pos.x >= 0 && pos.x <= clip_rect.right - clip_rect.left &&
478 pos.y >= 0 && pos.y <= clip_rect.bottom - clip_rect.top) {
479 if (!DrawIcon(gdigrab->
dest_hdc, pos.x, pos.y, icon))
481 }
482
483 icon_error:
484 if (icon)
485 DestroyCursor(icon);
486 } else {
488 }
489 }
490
491 /**
492 * Grabs a frame from gdi (public device demuxer API).
493 *
494 * @param s1 Context from avformat core
495 * @param pkt Packet holding the grabbed frame
496 * @return frame size in bytes
497 */
499 {
501
507
508 BITMAPFILEHEADER bfh;
510
511 int64_t curtime, delay;
512
513 /* Calculate the time of the next frame */
514 time_frame += INT64_C(1000000);
515
516 /* Run Window message processing queue */
519
520 /* wait based on the frame rate */
521 for (;;) {
523 delay = time_frame *
av_q2d(time_base) - curtime;
524 if (delay <= 0) {
525 if (delay < INT64_C(-1000000) *
av_q2d(time_base)) {
526 time_frame += INT64_C(1000000);
527 }
528 break;
529 }
532 } else {
534 }
535 }
536
540
541 /* Blit screen grab */
542 if (!BitBlt(dest_hdc, 0, 0,
543 clip_rect.right - clip_rect.left,
544 clip_rect.bottom - clip_rect.top,
545 source_hdc,
546 clip_rect.left, clip_rect.top, SRCCOPY | CAPTUREBLT)) {
549 }
552
553 /* Copy bits to packet data */
554
555 bfh.bfType = 0x4d42; /* "BM" in little-endian */
556 bfh.bfSize = file_size;
557 bfh.bfReserved1 = 0;
558 bfh.bfReserved2 = 0;
560
561 memcpy(pkt->
data, &bfh,
sizeof(bfh));
562
563 memcpy(pkt->
data +
sizeof(bfh), &gdigrab->
bmi.bmiHeader,
sizeof(gdigrab->
bmi.bmiHeader));
564
565 if (gdigrab->
bmi.bmiHeader.biBitCount <= 8)
566 GetDIBColorTable(dest_hdc, 0, 1 << gdigrab->
bmi.bmiHeader.biBitCount,
567 (RGBQUAD *) (pkt->
data +
sizeof(bfh) +
sizeof(gdigrab->
bmi.bmiHeader)));
568
570
572
574 }
575
576 /**
577 * Closes gdi frame grabber (public device demuxer API).
578 *
579 * @param s1 Context from avformat core
580 * @return 0 success, !0 failure
581 */
583 {
585
588
594 DeleteObject(s->
hbmp);
597
598 return 0;
599 }
600
601 #define OFFSET(x) offsetof(struct gdigrab, x)
602 #define DEC AV_OPT_FLAG_DECODING_PARAM
610 { NULL },
611 };
612
618 };
619
620 /** gdi grabber device demuxer declaration */
624 .priv_data_size =
sizeof(
struct gdigrab),
630 };