| Message ID | 20231214103241.25089-4-lena@nihil.gay |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,v3] gdigrab: Allow capturing a window by its handle | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | success | Make fate finished |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On date Thursday 2023-12-14 11:32:44 +0100, Lena wrote: > Updated the wording of the documentation, and added error checking for strtol. > > I looked at how other parts of the codebase check for errors on strtol and implemented it that way (iec61883, filter_units_bsf, etc). > > As for checking if the string value is larger/smaller than a long, i don't think there's a need, as the documentation says it'd just get set to LONG_MIN/LONG_MAX and fail anyway. > > > x11grab can capture windows by their ID, but gdigrab can only capture windows by their names, internally calling FindWindowW to lookup its handle. > > This patch simply allows the user to specify a window handle directly. > Signed-off-by: Lena <lena@nihil.gay> > --- > doc/indevs.texi | 8 ++++++-- > libavdevice/gdigrab.c | 15 ++++++++++++++- > 2 files changed, 20 insertions(+), 3 deletions(-) > > diff --git a/doc/indevs.texi b/doc/indevs.texi > index 863536a34d..a0c684f545 100644 > --- a/doc/indevs.texi > +++ b/doc/indevs.texi > @@ -722,7 +722,7 @@ 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: > +Amongst options for the imput filenames are such elements as: > @example > desktop > @end example > @@ -730,9 +730,13 @@ or > @example > title=@var{window_title} > @end example > +or > +@example > +hwnd=@var{window_hwnd} > +@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 > +desktop. The second and third options 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}: > diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c > index c069232472..3153b6f711 100644 > --- a/libavdevice/gdigrab.c > +++ b/libavdevice/gdigrab.c > @@ -273,9 +273,22 @@ gdigrab_read_header(AVFormatContext *s1) > } > } else if (!strcmp(filename, "desktop")) { > hwnd = NULL; > + } else if (!strncmp(filename, "hwnd=", 5)) { > + name = filename + 5; > + char *p; > + > + hwnd = strtol(name, &p, 0); > + > + if (p == NULL || p == name || p[0] == '\0') > + { > + av_log(s1, AV_LOG_ERROR, > + "Invalid window handle.\n"); Here you can provide some context: "Invalid window handle '%s', must be an valid integer.", name Looks good otherwise, thanks.
diff --git a/doc/indevs.texi b/doc/indevs.texi index 863536a34d..a0c684f545 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -722,7 +722,7 @@ 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: +Amongst options for the imput filenames are such elements as: @example desktop @end example @@ -730,9 +730,13 @@ or @example title=@var{window_title} @end example +or +@example +hwnd=@var{window_hwnd} +@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 +desktop. The second and third options 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}: diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c index c069232472..3153b6f711 100644 --- a/libavdevice/gdigrab.c +++ b/libavdevice/gdigrab.c @@ -273,9 +273,22 @@ gdigrab_read_header(AVFormatContext *s1) } } else if (!strcmp(filename, "desktop")) { hwnd = NULL; + } else if (!strncmp(filename, "hwnd=", 5)) { + name = filename + 5; + char *p; + + hwnd = strtol(name, &p, 0); + + if (p == NULL || p == name || p[0] == '\0') + { + av_log(s1, AV_LOG_ERROR, + "Invalid window handle.\n"); + ret = AVERROR(EINVAL); + goto error; + } } else { av_log(s1, AV_LOG_ERROR, - "Please use \"desktop\" or \"title=<windowname>\" to specify your target.\n"); + "Please use \"desktop\", \"title=<windowname>\" or \"hwnd=<hwnd>\" to specify your target.\n"); ret = AVERROR(EIO); goto error; }
Updated the wording of the documentation, and added error checking for strtol. I looked at how other parts of the codebase check for errors on strtol and implemented it that way (iec61883, filter_units_bsf, etc). As for checking if the string value is larger/smaller than a long, i don't think there's a need, as the documentation says it'd just get set to LONG_MIN/LONG_MAX and fail anyway. x11grab can capture windows by their ID, but gdigrab can only capture windows by their names, internally calling FindWindowW to lookup its handle. This patch simply allows the user to specify a window handle directly. Signed-off-by: Lena <lena@nihil.gay> --- doc/indevs.texi | 8 ++++++-- libavdevice/gdigrab.c | 15 ++++++++++++++- 2 files changed, 20 insertions(+), 3 deletions(-)