[FFmpeg-user] ffmpeg doesn't recognize the correct X resolusion when using x11grab

[Paul B Mahol]

On 5/16/13, Xeslaro <bfsc.yb at gmail.com> wrote:
>   i'm currently running under resolusion 1366x768 as i can see from the
> output of xrandr:
> Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
> LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis)
> 309mm x 174mm
>    1366x768       60.0*+
>    1024x768       60.0
>    800x600        60.3     56.2
>    640x480        59.9
> VGA1 disconnected (normal left inverted right x axis y axis)
> HDMI1 disconnected (normal left inverted right x axis y axis)
> DP1 disconnected (normal left inverted right x axis y axis)
>
>   however, ffmpeg thinks that i'm under 640x480, ffmpeg -f x11grab -i :0
> outputs:
> ffmpeg version N-53112-gd686517 Copyright (c) 2000-2013 the FFmpeg
> developers
>   built on May 16 2013 09:15:01 with gcc 4.6.4 (GCC)
>   configuration: --prefix=/home/xxx/p --enable-x11grab --enable-gpl
>   libavutil      52. 32.100 / 52. 32.100
>   libavcodec     55.  9.100 / 55.  9.100
>   libavformat    55.  7.100 / 55.  7.100
>   libavdevice    55.  0.100 / 55.  0.100
>   libavfilter     3. 68.101 /  3. 68.101
>   libswscale      2.  3.100 /  2.  3.100
>   libswresample   0. 17.102 /  0. 17.102
>   libpostproc    52.  3.100 / 52.  3.100
> [x11grab @ 0x9bf7e00] device: :0 -> display: :0 x: 0 y: 0 width: 640 height:
> 480
> [x11grab @ 0x9bf7e00] shared memory extension found
> Input #0, x11grab, from ':0':
>   Duration: N/A, start: 1368721262.140415, bitrate: 294617 kb/s
>     Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 640x480, 294617
> kb/s, 29.97 tbr, 1000k tbn, 29.97 tbc
> At least one output file must be specified
>
>   i'm running linux 3.9.0 with intel hd4000 graphic card, and the latest
> ffmpeg from git, and the 7.7 x.org release.
>   anyone knows why this happens?

Your reasoning is invalid, ffmpeg does not think anything about your
screen resolution.

Defaults resolution (when -video_size is not set) that x11grab is
using is vga aka 640x480.