GNOME Bugzilla – Bug 689278
[videoscale] Letter boxing bug
Last modified: 2012-11-29 14:01:52 UTC
Border gets added with proper aspect ratio only when pixel-aspect-ratio is set to 1 in filter caps. I would want to scale an image with letter box for maintaining display aspect ratio. I tried to upscale a 352x288 image to 640x360 by running the below mentioned command. I'm not satisfied with the result. Input is http://i49.tinypic.com/os51r6.png but the result is http://i47.tinypic.com/25ksm6s.png gst-launch-1.0 -v filesrc location=/mnt/temp/cif_test.yuv ! videoparse width=352 height=288 ! videoscale add-borders=1 ! video/x-raw,width=640,height=360 ! filesink location=/mnt/temp/out.yuv My log looked like Setting pipeline to PAUSED ... Pipeline is PREROLLING ... /GstPipeline:pipeline0/GstVideoParse:videoparse0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)352, height=(int)288, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 /GstPipeline:pipeline0/GstVideoScale:videoscale0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)640, height=(int)360, pixel-aspect-ratio=(fraction)11/16, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 /GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)640, height=(int)360, pixel-aspect-ratio=(fraction)11/16, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 /GstPipeline:pipeline0/GstFileSink:filesink0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)640, height=(int)360, pixel-aspect-ratio=(fraction)11/16, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 /GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)640, height=(int)360, pixel-aspect-ratio=(fraction)11/16, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 /GstPipeline:pipeline0/GstVideoScale:videoscale0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)352, height=(int)288, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, colorimetry=(string)bt601, framerate=(fraction)25/1 Pipeline is PREROLLED ... Setting pipeline to PLAYING ... New clock: GstSystemClock Got EOS from element "pipeline0". Execution ended after 3051953093 ns. Setting pipeline to PAUSED ... Setting pipeline to READY ... Setting pipeline to NULL ... Freeing pipeline ... This doesn't work: gst-launch-1.0 videotestsrc ! video/x-raw,width=352,height=288 ! videoscale add-borders=1 ! video/x-raw,width=640,height=360 ! xvimagesink This works: gst-launch-1.0 videotestsrc ! video/x-raw,width=352,height=288 ! videoscale add-borders=1 ! video/x-raw,width=640,height=360,pixel-aspect-ratio=1/1 ! xvimagesink
If you don't set a pixel-aspect-ratio after videoscale it assumes that downstream can handle all pixel-aspect-ratios and scales the video to the full size and passes a corresponding pixel-aspect-ratio in the caps downstream.