[FFmpeg-devel] [PATCH] Add Win32 GDI-based screen grabbing

Timothy Gu timothygu99 at gmail.com
Wed Apr 2 05:00:41 CEST 2014


On Apr 1, 2014 7:35 PM, "Michael Niedermayer" <michaelni at gmx.at> wrote:
>
> On Mon, Mar 24, 2014 at 04:36:37PM -0400, Calvin Walton wrote:
> > Based on original code by Chrisotphe 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 at kepstin.ca>
> > ---
> >  Changelog                |   1 +
> >  configure                |   5 +
> >  doc/general.texi         |   1 +
> >  doc/indevs.texi          |  75 ++++++
> >  libavdevice/Makefile     |   1 +
> >  libavdevice/alldevices.c |   1 +
> >  libavdevice/gdigrab.c    | 635
+++++++++++++++++++++++++++++++++++++++++++++++
> >  7 files changed, 719 insertions(+)
> >  create mode 100644 libavdevice/gdigrab.c
>
> this breaks compilation with mingw
>
> ffmpeg/libavdevice/gdigrab.c: In function 'gdigrab_region_wnd_init':
> ffmpeg/libavdevice/gdigrab.c:162:29: error: 'GWL_WNDPROC' undeclared
(first use in this function)
> ffmpeg/libavdevice/gdigrab.c:162:29: note: each undeclared identifier is
reported only once for each function it appears in
> ffmpeg/libavdevice/gdigrab.c: In function 'gdigrab_read_packet':

That should probably be *GWLP_**WNDPROC*. See
http://msdn.microsoft.com/en-us/library/windows/desktop/ms644898(v=vs.85).aspx.

But I'm not sure if that will fix compilation though. Are you using MinGW32
(i686-pc-mingw32) or mingw-w64 (*-w64-mingw32)?

Timothy


More information about the ffmpeg-devel mailing list