@@ -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:

@@ -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

@@ -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.

@@ -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.

@@ -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

@@ -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);

new file mode 100644

@@ -0,0 +1,630 @@

+/*

+ * 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;

+    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,

+};