diff options
| author | Mathieu Duponchelle <mathieu@centricular.com> | 2020-12-29 20:24:51 +0100 |
|---|---|---|
| committer | Tim-Philipp Müller <tim@centricular.com> | 2021-01-01 12:51:37 +0000 |
| commit | 0fdc1ca818a4d03e187b2467cf23fa4196ccb94d (patch) | |
| tree | 1ac831ae33b60ba5da3012692fac8d404d953449 | |
| parent | a85b149f1029f5d04d3c4d3c3b59d22147a3990b (diff) | |
| download | gstreamer-plugins-base-0fdc1ca818a4d03e187b2467cf23fa4196ccb94d.tar.gz | |
compositor/blend: fix blending of subsampled components
The correct way to determine the byte offset at a certain yoffset
in a subsampled component is to shift the yoffset by the component's
hsub
This fixes out-of-bounds memory accesses and visible artefacts,
example pipeline with the samples from #802:
gst-launch-1.0 compositor name=vmixer sink_1::xpos=1910 sink_1::ypos=1080 ! \
videoconvert ! videorate ! xvimagesink \
filesrc location=VID_20200723_203606.mp4 ! decodebin name=demux1 ! \
queue ! videoflip method=vertical-flip ! vmixer. \
filesrc location=bridgeoverstubbledwater.mp4 ! decodebin name=demux2 ! \
queue ! vmixer.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/989>
| -rw-r--r-- | gst/compositor/blend.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/gst/compositor/blend.c b/gst/compositor/blend.c index 41e20c033..531b47294 100644 --- a/gst/compositor/blend.c +++ b/gst/compositor/blend.c @@ -374,7 +374,7 @@ blend_##format_name (GstVideoFrame * srcframe, gint xpos, gint ypos, \ comp_xpos = (xpos == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (info, 1, xpos); \ comp_ypos = (ypos == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info, 1, ypos); \ comp_xoffset = (xoffset == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (info, 1, xoffset); \ - comp_yoffset = (yoffset == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info, 1, yoffset); \ + comp_yoffset = (yoffset == 0) ? 0 : yoffset >> info->h_sub[1]; \ _blend_##format_name (b_src + comp_xoffset + comp_yoffset * src_comp_rowstride, \ b_dest + comp_xpos + comp_ypos * dest_comp_rowstride, \ src_comp_rowstride, \ @@ -390,7 +390,7 @@ blend_##format_name (GstVideoFrame * srcframe, gint xpos, gint ypos, \ comp_xpos = (xpos == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (info, 2, xpos); \ comp_ypos = (ypos == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info, 2, ypos); \ comp_xoffset = (xoffset == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (info, 2, xoffset); \ - comp_yoffset = (yoffset == 0) ? 0 : GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info, 2, yoffset); \ + comp_yoffset = (yoffset == 0) ? 0 : yoffset >> info->h_sub[2]; \ _blend_##format_name (b_src + comp_xoffset + comp_yoffset * src_comp_rowstride, \ b_dest + comp_xpos + comp_ypos * dest_comp_rowstride, \ src_comp_rowstride, \ |