On 5 October 2015 at 19:29, Matt Oliver <protogo...@gmail.com> wrote:
> On 30 September 2015 at 02:48, wm4 <nfx...@googlemail.com> wrote:
>
>> On Wed, 23 Sep 2015 12:04:43 -0600
>> Roger Pack <rogerdpa...@gmail.com> wrote:
>>
>> > From 6a972dda58bd5ab31524cd4e5326b4bcdeaeaa8c Mon Sep 17 00:00:00 2001
>> > From: rogerdpack <rogerpack2...@gmail.com>
>> > Date: Wed, 23 Sep 2015 12:03:27 -0600
>> > Subject: [PATCH] gdigrab: grab right desktop size if DPI in use, based
>> on
>> > patch from Alexander Brotzge
>> >
>> > Signed-off-by: rogerdpack <rogerpack2...@gmail.com>
>> > ---
>> > libavdevice/gdigrab.c | 44 +++++++++++++++++++++++++++++---------------
>> > 1 file changed, 29 insertions(+), 15 deletions(-)
>> >
>> > diff --git a/libavdevice/gdigrab.c b/libavdevice/gdigrab.c
>> > index 9a185d4..b0faf45 100644
>> > --- a/libavdevice/gdigrab.c
>> > +++ b/libavdevice/gdigrab.c
>> > @@ -235,6 +235,9 @@ gdigrab_read_header(AVFormatContext *s1)
>> > AVStream *st = NULL;
>> >
>> > int bpp;
>> > + int vertres;
>> > + int desktopvertres;
>> > + float scale;
>> > RECT virtual_rect;
>> > RECT clip_rect;
>> > BITMAP bmp;
>> > @@ -263,14 +266,34 @@ gdigrab_read_header(AVFormatContext *s1)
>> > goto error;
>> > }
>> >
>> > - if (hwnd) {
>> > - GetClientRect(hwnd, &virtual_rect);
>> > - } else {
>> > + /* 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);
>> > +
>> > + scale = 1.0;
>> > + if (hwnd == NULL) {
>> > + /* desktop -- get the right height and width for scaling DPI */
>> > + vertres = GetDeviceCaps(source_hdc, VERTRES);
>> > + desktopvertres = GetDeviceCaps(source_hdc, DESKTOPVERTRES);
>> > + scale = (float) desktopvertres / (float) vertres;
>> > + }
>>
>
> This seems a little redundant as scale is only being set when hwnd is null
> however in the below lines its then being used in the opposite conditional.
> Since this checks for hwnd essentially being non null then scale is always
> going to be the inital value of 1.
>
>
>> > + if (hwnd) {
>> > + GetClientRect(hwnd, &virtual_rect);
>> > + virtual_rect.right = virtual_rect.right * scale;
>> > + virtual_rect.bottom = virtual_rect.bottom * scale;
>> > + } 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);
>> > - }
>> > + virtual_rect.right = (virtual_rect.left +
>> GetSystemMetrics(SM_CXVIRTUALSCREEN)) * scale;
>> > + virtual_rect.bottom = (virtual_rect.top +
>> GetSystemMetrics(SM_CYVIRTUALSCREEN)) * scale;
>> > + }
>>
>
> This if else could be combined with the above if as scale is only a value
> different to 1 in the 'else' case. Also as wm4 said it would probably be
> better to keep the scale factors as ints.
>
>
>> >
>> > /* If no width or height set, use full screen/window area */
>> > if (!gdigrab->width || !gdigrab->height) {
>> > @@ -299,15 +322,6 @@ gdigrab_read_header(AVFormatContext *s1)
>> > 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,
>
>
> However I think the basic dpi scaling technique is correct. However I
> would think it should be more along the lines of the modifications Ive
> attached.
>
Woops, allow me to try that again without windows messing up the patches
line endings.
0001-gdigrab-grab-right-desktop-size-if-DPI-in-use-based-.patch
Description: Binary data
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
