/* * GDI video grab interface * * This file is part of FFmpeg. * * Copyright (C) 2013 Calvin Walton <calvin.walton@kepstin.ca> * Copyright (C) 2007-2010 Christophe Gisquet <word1.word2@gmail.com> * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 * of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * GDI frame device demuxer * @author Calvin Walton <calvin.walton@kepstin.ca> * @author Christophe Gisquet <word1.word2@gmail.com> */ #include "config.h" #include "libavformat/internal.h" #include "libavutil/opt.h" #include "libavutil/time.h" #include <windows.h> /** * GDI Device Demuxer context */ struct gdigrab { const AVClass *class; /**< Class for private options */ int frame_size; /**< Size in bytes of the frame pixel data */ int header_size; /**< Size in bytes of the DIB header */ AVRational time_base; /**< Time base */ int64_t time_frame; /**< Current time */ int draw_mouse; /**< Draw mouse cursor (private option) */ int show_region; /**< Draw border (private option) */ AVRational framerate; /**< Capture framerate (private option) */ int width; /**< Width of the grab frame (private option) */ int height; /**< Height of the grab frame (private option) */ int offset_x; /**< Capture x offset (private option) */ int offset_y; /**< Capture y offset (private option) */ HWND hwnd; /**< Handle of the window for the grab */ HDC source_hdc; /**< Source device context */ HDC dest_hdc; /**< Destination, source-compatible DC */ BITMAPINFO bmi; /**< Information describing DIB format */ HBITMAP hbmp; /**< Information on the bitmap captured */ void *buffer; /**< The buffer containing the bitmap image data */ RECT clip_rect; /**< The subarea of the screen or window to clip */ HWND region_hwnd; /**< Handle of the region border window */ int cursor_error_printed; }; #define WIN32_API_ERROR(str) \ av_log(s1, AV_LOG_ERROR, str " (error %li)\n", GetLastError()) #define REGION_WND_BORDER 3 /** * Callback to handle Windows messages for the region outline window. * * In particular, this handles painting the frame rectangle. * * @param hwnd The region outline window handle. * @param msg The Windows message. * @param wparam First Windows message parameter. * @param lparam Second Windows message parameter. * @return 0 success, !0 failure */ static LRESULT CALLBACK gdigrab_region_wnd_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) { PAINTSTRUCT ps; HDC hdc; RECT rect; switch (msg) { case WM_PAINT: hdc = BeginPaint(hwnd, &ps); GetClientRect(hwnd, &rect); FrameRect(hdc, &rect, GetStockObject(BLACK_BRUSH)); rect.left++; rect.top++; rect.right--; rect.bottom--; FrameRect(hdc, &rect, GetStockObject(WHITE_BRUSH)); rect.left++; rect.top++; rect.right--; rect.bottom--; FrameRect(hdc, &rect, GetStockObject(BLACK_BRUSH)); EndPaint(hwnd, &ps); break; default: return DefWindowProc(hwnd, msg, wparam, lparam); } return 0; } /** * Initialize the region outline window. * * @param s1 The format context. * @param gdigrab gdigrab context. * @return 0 success, !0 failure */ static int gdigrab_region_wnd_init(AVFormatContext *s1, struct gdigrab *gdigrab) { HWND hwnd; RECT rect = gdigrab->clip_rect; HRGN region = NULL; HRGN region_interior = NULL; DWORD style = WS_POPUP | WS_VISIBLE; DWORD ex = WS_EX_TOOLWINDOW | WS_EX_TOPMOST | WS_EX_TRANSPARENT; rect.left -= REGION_WND_BORDER; rect.top -= REGION_WND_BORDER; rect.right += REGION_WND_BORDER; rect.bottom += REGION_WND_BORDER; AdjustWindowRectEx(&rect, style, FALSE, ex); // Create a window with no owner; use WC_DIALOG instead of writing a custom // window class hwnd = CreateWindowEx(ex, WC_DIALOG, NULL, style, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, NULL, NULL, NULL, NULL); if (!hwnd) { WIN32_API_ERROR("Could not create region display window"); goto error; } // Set the window shape to only include the border area GetClientRect(hwnd, &rect); region = CreateRectRgn(0, 0, rect.right - rect.left, rect.bottom - rect.top); region_interior = CreateRectRgn(REGION_WND_BORDER, REGION_WND_BORDER, rect.right - rect.left - REGION_WND_BORDER, rect.bottom - rect.top - REGION_WND_BORDER); CombineRgn(region, region, region_interior, RGN_DIFF); if (!SetWindowRgn(hwnd, region, FALSE)) { WIN32_API_ERROR("Could not set window region"); goto error; } // The "region" memory is now owned by the window region = NULL; DeleteObject(region_interior); SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR) gdigrab_region_wnd_proc); ShowWindow(hwnd, SW_SHOW); gdigrab->region_hwnd = hwnd; return 0; error: if (region) DeleteObject(region); if (region_interior) DeleteObject(region_interior); if (hwnd) DestroyWindow(hwnd); return 1; } /** * Cleanup/free the region outline window. * * @param s1 The format context. * @param gdigrab gdigrab context. */ static void gdigrab_region_wnd_destroy(AVFormatContext *s1, struct gdigrab *gdigrab) { if (gdigrab->region_hwnd) DestroyWindow(gdigrab->region_hwnd); gdigrab->region_hwnd = NULL; } /** * Process the Windows message queue. * * This is important to prevent Windows from thinking the window has become * unresponsive. As well, things like WM_PAINT (to actually draw the window * contents) are handled from the message queue context. * * @param s1 The format context. * @param gdigrab gdigrab context. */ static void gdigrab_region_wnd_update(AVFormatContext *s1, struct gdigrab *gdigrab) { HWND hwnd = gdigrab->region_hwnd; MSG msg; while (PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE)) { DispatchMessage(&msg); } } /** * Initializes the gdi grab device demuxer (public device demuxer API). * * @param s1 Context from avformat core * @return AVERROR_IO error, 0 success */ static int gdigrab_read_header(AVFormatContext *s1) { struct gdigrab *gdigrab = s1->priv_data; HWND hwnd; HDC source_hdc = NULL; HDC dest_hdc = NULL; BITMAPINFO bmi; HBITMAP hbmp = NULL; void *buffer = NULL; const char *filename = s1->filename; const char *name = NULL; AVStream *st = NULL; int bpp; int vertres; int desktopvertres; RECT virtual_rect; RECT clip_rect; BITMAP bmp; int ret; if (!strncmp(filename, "title=", 6)) { name = filename + 6; hwnd = FindWindow(NULL, name); if (!hwnd) { av_log(s1, AV_LOG_ERROR, "Can't find window '%s', aborting.\n", name); ret = AVERROR(EIO); goto error; } if (gdigrab->show_region) { av_log(s1, AV_LOG_WARNING, "Can't show region when grabbing a window.\n"); gdigrab->show_region = 0; } } else if (!strcmp(filename, "desktop")) { hwnd = NULL; } else { av_log(s1, AV_LOG_ERROR, "Please use \"desktop\" or \"title=<windowname>\" to specify your target.\n"); ret = AVERROR(EIO); goto error; } /* This will get the device context for the selected window, or if * none, the primary screen */ source_hdc = GetDC(hwnd); if (!source_hdc) { WIN32_API_ERROR("Couldn't get window device context"); ret = AVERROR(EIO); goto error; } bpp = GetDeviceCaps(source_hdc, BITSPIXEL); if (hwnd) { GetClientRect(hwnd, &virtual_rect); } else { /* desktop -- get the right height and width for scaling DPI */ vertres = GetDeviceCaps(source_hdc, VERTRES); desktopvertres = GetDeviceCaps(source_hdc, DESKTOPVERTRES); virtual_rect.left = GetSystemMetrics(SM_XVIRTUALSCREEN); virtual_rect.top = GetSystemMetrics(SM_YVIRTUALSCREEN); virtual_rect.right = (virtual_rect.left + GetSystemMetrics(SM_CXVIRTUALSCREEN)) * desktopvertres / vertres; virtual_rect.bottom = (virtual_rect.top + GetSystemMetrics(SM_CYVIRTUALSCREEN)) * desktopvertres / vertres; } /* If no width or height set, use full screen/window area */ if (!gdigrab->width || !gdigrab->height) { clip_rect.left = virtual_rect.left; clip_rect.top = virtual_rect.top; clip_rect.right = virtual_rect.right; clip_rect.bottom = virtual_rect.bottom; } else { clip_rect.left = gdigrab->offset_x; clip_rect.top = gdigrab->offset_y; clip_rect.right = gdigrab->width + gdigrab->offset_x; clip_rect.bottom = gdigrab->height + gdigrab->offset_y; } if (clip_rect.left < virtual_rect.left || clip_rect.top < virtual_rect.top || clip_rect.right > virtual_rect.right || clip_rect.bottom > virtual_rect.bottom) { av_log(s1, AV_LOG_ERROR, "Capture area (%li,%li),(%li,%li) extends outside window area (%li,%li),(%li,%li)", clip_rect.left, clip_rect.top, clip_rect.right, clip_rect.bottom, virtual_rect.left, virtual_rect.top, virtual_rect.right, virtual_rect.bottom); ret = AVERROR(EIO); goto error; } if (name) { av_log(s1, AV_LOG_INFO, "Found window %s, capturing %lix%lix%i at (%li,%li)\n", name, clip_rect.right - clip_rect.left, clip_rect.bottom - clip_rect.top, bpp, clip_rect.left, clip_rect.top); } else { av_log(s1, AV_LOG_INFO, "Capturing whole desktop as %lix%lix%i at (%li,%li)\n", clip_rect.right - clip_rect.left, clip_rect.bottom - clip_rect.top, bpp, clip_rect.left, clip_rect.top); } if (clip_rect.right - clip_rect.left <= 0 || clip_rect.bottom - clip_rect.top <= 0 || bpp%8) { av_log(s1, AV_LOG_ERROR, "Invalid properties, aborting\n"); ret = AVERROR(EIO); goto error; } dest_hdc = CreateCompatibleDC(source_hdc); if (!dest_hdc) { WIN32_API_ERROR("Screen DC CreateCompatibleDC"); ret = AVERROR(EIO); goto error; } /* Create a DIB and select it into the dest_hdc */ bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmi.bmiHeader.biWidth = clip_rect.right - clip_rect.left; bmi.bmiHeader.biHeight = -(clip_rect.bottom - clip_rect.top); bmi.bmiHeader.biPlanes = 1; bmi.bmiHeader.biBitCount = bpp; bmi.bmiHeader.biCompression = BI_RGB; bmi.bmiHeader.biSizeImage = 0; bmi.bmiHeader.biXPelsPerMeter = 0; bmi.bmiHeader.biYPelsPerMeter = 0; bmi.bmiHeader.biClrUsed = 0; bmi.bmiHeader.biClrImportant = 0; hbmp = CreateDIBSection(dest_hdc, &bmi, DIB_RGB_COLORS, &buffer, NULL, 0); if (!hbmp) { WIN32_API_ERROR("Creating DIB Section"); ret = AVERROR(EIO); goto error; } if (!SelectObject(dest_hdc, hbmp)) { WIN32_API_ERROR("SelectObject"); ret = AVERROR(EIO); goto error; } /* Get info from the bitmap */ GetObject(hbmp, sizeof(BITMAP), &bmp); st = avformat_new_stream(s1, NULL); if (!st) { ret = AVERROR(ENOMEM); goto error; } avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */ gdigrab->frame_size = bmp.bmWidthBytes * bmp.bmHeight * bmp.bmPlanes; gdigrab->header_size = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + (bpp <= 8 ? (1 << bpp) : 0) * sizeof(RGBQUAD) /* palette size */; gdigrab->time_base = av_inv_q(gdigrab->framerate); gdigrab->time_frame = av_gettime() / av_q2d(gdigrab->time_base); gdigrab->hwnd = hwnd; gdigrab->source_hdc = source_hdc; gdigrab->dest_hdc = dest_hdc; gdigrab->hbmp = hbmp; gdigrab->bmi = bmi; gdigrab->buffer = buffer; gdigrab->clip_rect = clip_rect; gdigrab->cursor_error_printed = 0; if (gdigrab->show_region) { if (gdigrab_region_wnd_init(s1, gdigrab)) { ret = AVERROR(EIO); goto error; } } st->avg_frame_rate = av_inv_q(gdigrab->time_base); st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; st->codecpar->codec_id = AV_CODEC_ID_BMP; st->codecpar->bit_rate = (gdigrab->header_size + gdigrab->frame_size) * 1/av_q2d(gdigrab->time_base) * 8; return 0; error: if (source_hdc) ReleaseDC(hwnd, source_hdc); if (dest_hdc) DeleteDC(dest_hdc); if (hbmp) DeleteObject(hbmp); if (source_hdc) DeleteDC(source_hdc); return ret; } /** * Paints a mouse pointer in a Win32 image. * * @param s1 Context of the log information * @param s Current grad structure */ static void paint_mouse_pointer(AVFormatContext *s1, struct gdigrab *gdigrab) { CURSORINFO ci = {0}; #define CURSOR_ERROR(str) \ if (!gdigrab->cursor_error_printed) { \ WIN32_API_ERROR(str); \ gdigrab->cursor_error_printed = 1; \ } ci.cbSize = sizeof(ci); if (GetCursorInfo(&ci)) { HCURSOR icon = CopyCursor(ci.hCursor); ICONINFO info; POINT pos; RECT clip_rect = gdigrab->clip_rect; HWND hwnd = gdigrab->hwnd; int vertres = GetDeviceCaps(gdigrab->source_hdc, VERTRES); int desktopvertres = GetDeviceCaps(gdigrab->source_hdc, DESKTOPVERTRES); info.hbmMask = NULL; info.hbmColor = NULL; if (ci.flags != CURSOR_SHOWING) return; if (!icon) { /* Use the standard arrow cursor as a fallback. * You'll probably only hit this in Wine, which can't fetch * the current system cursor. */ icon = CopyCursor(LoadCursor(NULL, IDC_ARROW)); } if (!GetIconInfo(icon, &info)) { CURSOR_ERROR("Could not get icon info"); goto icon_error; } pos.x = ci.ptScreenPos.x - clip_rect.left - info.xHotspot; pos.y = ci.ptScreenPos.y - clip_rect.top - info.yHotspot; if (hwnd) { RECT rect; if (GetWindowRect(hwnd, &rect)) { pos.x -= rect.left; pos.y -= rect.top; } else { CURSOR_ERROR("Couldn't get window rectangle"); goto icon_error; } } //that would keep the correct location of mouse with hidpi screens pos.x = pos.x * desktopvertres / vertres; pos.y = pos.y * desktopvertres / vertres; av_log(s1, AV_LOG_DEBUG, "Cursor pos (%li,%li) -> (%li,%li)\n", ci.ptScreenPos.x, ci.ptScreenPos.y, pos.x, pos.y); if (pos.x >= 0 && pos.x <= clip_rect.right - clip_rect.left && pos.y >= 0 && pos.y <= clip_rect.bottom - clip_rect.top) { if (!DrawIcon(gdigrab->dest_hdc, pos.x, pos.y, icon)) CURSOR_ERROR("Couldn't draw icon"); } icon_error: if (info.hbmMask) DeleteObject(info.hbmMask); if (info.hbmColor) DeleteObject(info.hbmColor); if (icon) DestroyCursor(icon); } else { CURSOR_ERROR("Couldn't get cursor info"); } } /** * Grabs a frame from gdi (public device demuxer API). * * @param s1 Context from avformat core * @param pkt Packet holding the grabbed frame * @return frame size in bytes */ static int gdigrab_read_packet(AVFormatContext *s1, AVPacket *pkt) { struct gdigrab *gdigrab = s1->priv_data; HDC dest_hdc = gdigrab->dest_hdc; HDC source_hdc = gdigrab->source_hdc; RECT clip_rect = gdigrab->clip_rect; AVRational time_base = gdigrab->time_base; int64_t time_frame = gdigrab->time_frame; BITMAPFILEHEADER bfh; int file_size = gdigrab->header_size + gdigrab->frame_size; int64_t curtime, delay; /* Calculate the time of the next frame */ time_frame += INT64_C(1000000); /* Run Window message processing queue */ if (gdigrab->show_region) gdigrab_region_wnd_update(s1, gdigrab); /* wait based on the frame rate */ for (;;) { curtime = av_gettime(); delay = time_frame * av_q2d(time_base) - curtime; if (delay <= 0) { if (delay < INT64_C(-1000000) * av_q2d(time_base)) { time_frame += INT64_C(1000000); } break; } if (s1->flags & AVFMT_FLAG_NONBLOCK) { return AVERROR(EAGAIN); } else { av_usleep(delay); } } if (av_new_packet(pkt, file_size) < 0) return AVERROR(ENOMEM); pkt->pts = curtime; /* Blit screen grab */ if (!BitBlt(dest_hdc, 0, 0, clip_rect.right - clip_rect.left, clip_rect.bottom - clip_rect.top, source_hdc, clip_rect.left, clip_rect.top, SRCCOPY | CAPTUREBLT)) { WIN32_API_ERROR("Failed to capture image"); return AVERROR(EIO); } if (gdigrab->draw_mouse) paint_mouse_pointer(s1, gdigrab); /* Copy bits to packet data */ bfh.bfType = 0x4d42; /* "BM" in little-endian */ bfh.bfSize = file_size; bfh.bfReserved1 = 0; bfh.bfReserved2 = 0; bfh.bfOffBits = gdigrab->header_size; memcpy(pkt->data, &bfh, sizeof(bfh)); memcpy(pkt->data + sizeof(bfh), &gdigrab->bmi.bmiHeader, sizeof(gdigrab->bmi.bmiHeader)); if (gdigrab->bmi.bmiHeader.biBitCount <= 8) GetDIBColorTable(dest_hdc, 0, 1 << gdigrab->bmi.bmiHeader.biBitCount, (RGBQUAD *) (pkt->data + sizeof(bfh) + sizeof(gdigrab->bmi.bmiHeader))); memcpy(pkt->data + gdigrab->header_size, gdigrab->buffer, gdigrab->frame_size); gdigrab->time_frame = time_frame; return gdigrab->header_size + gdigrab->frame_size; } /** * Closes gdi frame grabber (public device demuxer API). * * @param s1 Context from avformat core * @return 0 success, !0 failure */ static int gdigrab_read_close(AVFormatContext *s1) { struct gdigrab *s = s1->priv_data; if (s->show_region) gdigrab_region_wnd_destroy(s1, s); if (s->source_hdc) ReleaseDC(s->hwnd, s->source_hdc); if (s->dest_hdc) DeleteDC(s->dest_hdc); if (s->hbmp) DeleteObject(s->hbmp); if (s->source_hdc) DeleteDC(s->source_hdc); return 0; } #define OFFSET(x) offsetof(struct gdigrab, x) #define DEC AV_OPT_FLAG_DECODING_PARAM static const AVOption options[] = { { "draw_mouse", "draw the mouse pointer", OFFSET(draw_mouse), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, DEC }, { "show_region", "draw border around capture area", OFFSET(show_region), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC }, { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "ntsc"}, 0, INT_MAX, DEC }, { "video_size", "set video frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC }, { "offset_x", "capture area x offset", OFFSET(offset_x), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC }, { "offset_y", "capture area y offset", OFFSET(offset_y), AV_OPT_TYPE_INT, {.i64 = 0}, INT_MIN, INT_MAX, DEC }, { NULL }, }; static const AVClass gdigrab_class = { .class_name = "GDIgrab indev", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; /** gdi grabber device demuxer declaration */ AVInputFormat ff_gdigrab_demuxer = { .name = "gdigrab", .long_name = NULL_IF_CONFIG_SMALL("GDI API Windows frame grabber"), .priv_data_size = sizeof(struct gdigrab), .read_header = gdigrab_read_header, .read_packet = gdigrab_read_packet, .read_close = gdigrab_read_close, .flags = AVFMT_NOFILE, .priv_class = &gdigrab_class, };