Based on original code by Christophe Gisquet in 2010, updated to work
with current ffmpeg APIs.
Supports grabbing a single window or an area of the screen, including
support for multiple monitors (Windows does funky stuff with negative
coordinates here).
I've moved most of the configuration to AVOptions; the input file name
is now only the string "desktop", or "title=<windowname>" to select a
single window. The AVOptions are the same as x11grab where possible.
Code has been added to support a "show_region" mode, like x11grab, which
will draw a rectangle on the screen around the area being captured.
Instead of duplicating code for paletted image handling, I make use of
the GDI API's ability to output DIB (BMP) images, which can be run
through ffmpeg's existing BMP decoder.
Signed-off-by: Calvin Walton <calvin.walton(a)kepstin.ca>
---
Notes:
Revised patch fixes the spelling of Christophe's name, and corrects
the build failure seen on 64-bit. It also removes an old debug
statement that was causing some printf format warnings on 64bit.
Changelog | 1 +
configure | 5 +
doc/general.texi | 1 +
doc/indevs.texi | 75 ++++++
libavdevice/Makefile | 1 +
libavdevice/alldevices.c | 1 +
libavdevice/gdigrab.c | 630 +++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 714 insertions(+)
create mode 100644 libavdevice/gdigrab.c
diff --git a/Changelog b/Changelog
index 8fb77b8..3c11eb6 100644
--- a/Changelog
+++ b/Changelog
@@ -14,6 +14,7 @@ version <next>:
- QTKit input device
- improvments to OpenEXR image decoder
- support decoding 16-bit RLE SGI images
+- GDI screen grabbing for Windows
version 2.2:
diff --git a/configure b/configure
index 848dc7e..46452ee 100755
--- a/configure
+++ b/configure
@@ -2349,6 +2349,9 @@ dv1394_indev_deps="dv1394"
dv1394_indev_select="dv_demuxer"
fbdev_indev_deps="linux_fb_h"
fbdev_outdev_deps="linux_fb_h"
+gdigrab_indev_deps="CreateDIBSection"
+gdigrab_indev_extralibs="-lgdi32"
+gdigrab_indev_select="bmp_decoder"
iec61883_indev_deps="libiec61883"
jack_indev_deps="jack_jack_h sem_timedwait"
lavfi_indev_deps="avfilter"
@@ -4741,6 +4744,8 @@ require Xext X11/extensions/XShm.h XShmCreateImage -lXext &&
require Xfixes X11/extensions/Xfixes.h XFixesGetCursorImage -lXfixes &&
{ enabled xlib || die "ERROR: Xlib not found"; }
+check_func_headers "windows.h" CreateDIBSection "$gdigrab_indev_extralibs"
+
enabled vaapi &&
check_lib va/va.h vaInitialize -lva ||
disable vaapi
diff --git a/doc/general.texi b/doc/general.texi
index 9f17d48..f533f40 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -1088,6 +1088,7 @@ performance on systems without hardware floating point support).
@item Video4Linux2 @tab X @tab X
@item VfW capture @tab X @tab
@item X11 grabbing @tab X @tab
+@item Win32 grabbing @tab X @tab
@end multitable
@code{X} means that input/output is supported.
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 68905ae..ecf97cc 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -192,6 +192,81 @@ ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
See also @url{http://linux-fbdev.sourceforge.net/}, and fbset(1).
+@section gdigrab
+
+Win32 GDI-based screen capture device.
+
+This device allows you to capture a region of the display on Windows.
+
+There are two options for the input filename:
+@example
+desktop
+@end example
+or
+@example
+title=@var{window_title}
+@end example
+
+The first option will capture the entire desktop, or a fixed region of the
+desktop. The second option will instead capture the contents of a single
+window, regardless of its position on the screen.
+
+For example, to grab the entire desktop using @command{ffmpeg}:
+@example
+ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
+@end example
+
+Grab a 640x480 region at position @code{10,20}:
+@example
+ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
+@end example
+
+Grab the contents of the window named "Calculator"
+@example
+ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
+@end example
+
+@subsection Options
+
+@table @option
+@item draw_mouse
+Specify whether to draw the mouse pointer. Use the value @code{0} to
+not draw the pointer. Default value is @code{1}.
+
+@item framerate
+Set the grabbing frame rate. Default value is @code{ntsc},
+corresponding to a frame rate of @code{30000/1001}.
+
+@item show_region
+Show grabbed region on screen.
+
+If @var{show_region} is specified with @code{1}, then the grabbing
+region will be indicated on screen. With this option, it is easy to
+know what is being grabbed if only a portion of the screen is grabbed.
+
+Note that @var{show_region} is incompatible with grabbing the contents
+of a single window.
+
+For example:
+@example
+ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
+@end example
+
+@item video_size
+Set the video frame size. The default is to capture the full screen if @file{desktop} is selected, or the full window size if @file{title=@var{window_title}} is selected.
+
+@item offset_x
+When capturing a region with @var{video_size}, set the distance from the left edge of the screen or desktop.
+
+Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative @var{offset_x} value to move the region to that monitor.
+
+@item offset_y
+When capturing a region with @var{video_size}, set the distance from the top edge of the screen or desktop.
+
+Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative @var{offset_y} value to move the region to that monitor.
+
+@end table
+
@section iec61883
FireWire DV/HDV input device using libiec61883.
diff --git a/libavdevice/Makefile b/libavdevice/Makefile
index 7e5f9bf..68b65cc 100644
--- a/libavdevice/Makefile
+++ b/libavdevice/Makefile
@@ -26,6 +26,7 @@ OBJS-$(CONFIG_FBDEV_INDEV) += fbdev_dec.o \
fbdev_common.o
OBJS-$(CONFIG_FBDEV_OUTDEV) += fbdev_enc.o \
fbdev_common.o
+OBJS-$(CONFIG_GDIGRAB_INDEV) += gdigrab.o
OBJS-$(CONFIG_IEC61883_INDEV) += iec61883.o
OBJS-$(CONFIG_JACK_INDEV) += jack_audio.o timefilter.o
OBJS-$(CONFIG_LAVFI_INDEV) += lavfi.o
diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
index 282c50e..9164d68 100644
--- a/libavdevice/alldevices.c
+++ b/libavdevice/alldevices.c
@@ -53,6 +53,7 @@ void avdevice_register_all(void)
REGISTER_INDEV (DSHOW, dshow);
REGISTER_INDEV (DV1394, dv1394);
REGISTER_INOUTDEV(FBDEV, fbdev);
+ REGISTER_INDEV (GDIGRAB, gdigrab);
REGISTER_INDEV (IEC61883, iec61883);
REGISTER_INDEV (JACK, jack);
REGISTER_INDEV (LAVFI, lavfi);
diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c
new file mode 100644
index 0000000..bccfef2
--- /dev/null
+++ b/libavdevice/gdigrab.c
@@ -0,0 +1,630 @@
+/*
+ * GDI video grab interface
+ *
+ * This file is part of FFmpeg.
+ *
+ * Copyright (C) 2013 Calvin Walton <calvin.walton(a)kepstin.ca>
+ * Copyright (C) 2007-2010 Christophe Gisquet <word1.word2(a)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(a)kepstin.ca>
+ * @author Christophe Gisquet <word1.word2(a)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;
+ 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;
+ }
+
+ if (hwnd) {
+ GetClientRect(hwnd, &virtual_rect);
+ } else {
+ virtual_rect.left = GetSystemMetrics(SM_XVIRTUALSCREEN);
+ virtual_rect.top = GetSystemMetrics(SM_YVIRTUALSCREEN);
+ virtual_rect.right = virtual_rect.left + GetSystemMetrics(SM_CXVIRTUALSCREEN);
+ virtual_rect.bottom = virtual_rect.top + GetSystemMetrics(SM_CYVIRTUALSCREEN);
+ }
+
+ /* 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;
+ }
+
+ /* 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 (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->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+ st->codec->codec_id = AV_CODEC_ID_BMP;
+ st->codec->time_base = gdigrab->time_base;
+ st->codec->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;
+
+ 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;
+ }
+ }
+
+ 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 (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, 0, 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,
+};
--
1.8.3.2
