gdigrab.c File Reference

GDI frame device demuxer. More...

#include "config.h"
#include "libavformat/internal.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include <windows.h>

Go to the source code of this file.

Data Structures
struct	gdigrab
	GDI Device Demuxer context. More...

Macros
#define	WIN32_API_ERROR(str)   av_log(s1, AV_LOG_ERROR, str " (error %li)\n", GetLastError())
#define	REGION_WND_BORDER   3
#define	CURSOR_ERROR(str)
#define	OFFSET(x)   offsetof(struct gdigrab, x)
#define	DEC   AV_OPT_FLAG_DECODING_PARAM

Functions
static LRESULT CALLBACK	gdigrab_region_wnd_proc (HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
	Callback to handle Windows messages for the region outline window. More...
static int	gdigrab_region_wnd_init (AVFormatContext *s1, struct gdigrab *gdigrab)
	Initialize the region outline window. More...
static void	gdigrab_region_wnd_destroy (AVFormatContext *s1, struct gdigrab *gdigrab)
	Cleanup/free the region outline window. More...
static void	gdigrab_region_wnd_update (AVFormatContext *s1, struct gdigrab *gdigrab)
	Process the Windows message queue. More...
static int	gdigrab_read_header (AVFormatContext *s1)
	Initializes the gdi grab device demuxer (public device demuxer API). More...
static void	paint_mouse_pointer (AVFormatContext *s1, struct gdigrab *gdigrab)
	Paints a mouse pointer in a Win32 image. More...
static int	gdigrab_read_packet (AVFormatContext *s1, AVPacket *pkt)
	Grabs a frame from gdi (public device demuxer API). More...
static int	gdigrab_read_close (AVFormatContext *s1)
	Closes gdi frame grabber (public device demuxer API). More...

Variables
static const AVOption	options []
static const AVClass	gdigrab_class
AVInputFormat	ff_gdigrab_demuxer
	gdi grabber device demuxer declaration More...

Detailed Description

GDI frame device demuxer.

Author

Calvin Walton calvi.nosp@m.n.wa.nosp@m.lton@.nosp@m.keps.nosp@m.tin.c.nosp@m.a

Christophe Gisquet word1.nosp@m..wor.nosp@m.d2@gm.nosp@m.ail..nosp@m.com

Definition in file gdigrab.c.

Macro Definition Documentation

#define WIN32_API_ERROR

(

str

)

av_log(s1, AV_LOG_ERROR, str " (error %li)\n", GetLastError())

Definition at line 69 of file gdigrab.c.

Referenced by gdigrab_read_header(), gdigrab_read_packet(), and gdigrab_region_wnd_init().

#define REGION_WND_BORDER   3

Definition at line 72 of file gdigrab.c.

Referenced by gdigrab_region_wnd_init().

#define CURSOR_ERROR

(

str

)

Value:

if (!gdigrab->cursor_error_printed) {       \
        WIN32_API_ERROR(str);             \
        gdigrab->cursor_error_printed = 1;      \
    }

Referenced by paint_mouse_pointer().

#define OFFSET

(

x

)

offsetof(struct gdigrab, x)

Definition at line 613 of file gdigrab.c.

#define DEC   AV_OPT_FLAG_DECODING_PARAM

Definition at line 614 of file gdigrab.c.

Function Documentation

static LRESULT CALLBACK gdigrab_region_wnd_proc ( HWND  hwnd, UINT  msg, WPARAM  wparam, LPARAM  lparam  )

static

Callback to handle Windows messages for the region outline window.

In particular, this handles painting the frame rectangle.

Parameters

hwnd	The region outline window handle.
msg	The Windows message.
wparam	First Windows message parameter.
lparam	Second Windows message parameter.

Returns

0 success, !0 failure

Definition at line 86 of file gdigrab.c.

Referenced by gdigrab_region_wnd_init().

static int gdigrab_region_wnd_init ( AVFormatContext *  s1, struct gdigrab *  gdigrab  )

static

Initialize the region outline window.

Parameters

s1	The format context.
gdigrab	gdigrab context.

Returns

0 success, !0 failure

Definition at line 121 of file gdigrab.c.

Referenced by gdigrab_read_header().

static void gdigrab_region_wnd_destroy ( AVFormatContext *  s1, struct gdigrab *  gdigrab  )

static

Cleanup/free the region outline window.

Parameters

s1	The format context.
gdigrab	gdigrab context.

Definition at line 187 of file gdigrab.c.

Referenced by gdigrab_read_close().

static void gdigrab_region_wnd_update ( AVFormatContext *  s1, struct gdigrab *  gdigrab  )

static

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.

Parameters

s1	The format context.
gdigrab	gdigrab context.

Definition at line 205 of file gdigrab.c.

Referenced by gdigrab_read_packet().

static int gdigrab_read_header ( AVFormatContext *  s1 )

static

Initializes the gdi grab device demuxer (public device demuxer API).

Parameters

s1	Context from avformat core

Returns

AVERROR_IO error, 0 success

Definition at line 222 of file gdigrab.c.

static void paint_mouse_pointer ( AVFormatContext *  s1, struct gdigrab *  gdigrab  )

static

Paints a mouse pointer in a Win32 image.

Parameters

s1	Context of the log information
s	Current grad structure

Definition at line 431 of file gdigrab.c.

Referenced by gdigrab_read_packet().

static int gdigrab_read_packet ( AVFormatContext *  s1, AVPacket *  pkt  )

static

Grabs a frame from gdi (public device demuxer API).

Parameters

s1	Context from avformat core
pkt	Packet holding the grabbed frame

Returns

frame size in bytes

Definition at line 510 of file gdigrab.c.

static int gdigrab_read_close ( AVFormatContext *  s1 )

static

Closes gdi frame grabber (public device demuxer API).

Parameters

s1	Context from avformat core

Returns

0 success, !0 failure

Definition at line 594 of file gdigrab.c.

Variable Documentation

const AVOption options[]

static

Initial value:

= {
    { "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 },
}

Definition at line 615 of file gdigrab.c.

const AVClass gdigrab_class

static

Initial value:

= {
    .class_name = "GDIgrab indev",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
}

Definition at line 625 of file gdigrab.c.

AVInputFormat ff_gdigrab_demuxer

Initial value:

= {
    .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,
}

gdi grabber device demuxer declaration

Definition at line 633 of file gdigrab.c.