| Message ID | 20190409220730.29311-2-sw@jkqxz.net |
|---|---|
| State | New |
| Headers | show |
> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces@ffmpeg.org] On Behalf Of > Mark Thompson > Sent: Wednesday, April 10, 2019 6:07 AM > To: ffmpeg-devel@ffmpeg.org > Subject: [FFmpeg-devel] [PATCH v4 2/7] doc/indevs: Add example using cropping > to capture part of a plane > > --- > doc/indevs.texi | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/doc/indevs.texi b/doc/indevs.texi > index 1d5ed65773..a4f0f608d7 100644 > --- a/doc/indevs.texi > +++ b/doc/indevs.texi > @@ -910,6 +910,14 @@ Capture from CRTC ID 42 at 60fps, map the result to > VAAPI, convert to NV12 and e > ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf > 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v > h264_vaapi output.mp4 > @end example > > +@item > +To capture only part of a plane the output can be cropped - this can be used to > capture > +a single window, as long as it has a known absolute position. For example, to absolute position and window size? > capture > +and encode the middle quarter of a 1920x1080 plane: > +@example > +ffmpeg -f kmsgrab -i - -vf > 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' > -c:v h264_vaapi output.mp4 > +@end example > + > @end itemize > > @section lavfi > -- > 2.20.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
diff --git a/doc/indevs.texi b/doc/indevs.texi index 1d5ed65773..a4f0f608d7 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -910,6 +910,14 @@ Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert to NV12 and e ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4 @end example +@item +To capture only part of a plane the output can be cropped - this can be used to capture +a single window, as long as it has a known absolute position. For example, to capture +and encode the middle quarter of a 1920x1080 plane: +@example +ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4 +@end example + @end itemize @section lavfi