Hi Fabio, On Mon, 2021-01-18 at 10:28 -0300, Fabio Estevam wrote: > Hi Philipp, > > Thanks for your reply. > > On Mon, Jan 18, 2021 at 9:40 AM Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote: > > > The driver could be modified to switch the DP->DI0/DC->DI1 mapping > > around to DP->DI1/DC->DI0 when required. As a simple test, you can > > switch statically with: > > It does change the colors but still does not play the video with the > correct colors. Looks like it plays in black-and-white now. Please try forcing decoder output to NV12 instead of I420. > > Or, as a workaround, add a v4l2convert element and use the IC to convert > > to BGRx between decoder and kmssink. > > Yes, I have tried to do this, but it says that v4l2convert does not > support bt601 colorimetry, and then a segfault occurs: > > # gst-launch-1.0 filesrc location=/media/clip.mp4 ! qtdemux ! > h264parse ! v4l2h264dec ! v4l2convert ! video/x-raw,format=BGRx ! > kmssink > Setting pipeline to PAUSED ... > Pipeline is PREROLLING ... > ERROR: from element /GstPipeline:pipeline0/v4l2convert:v4l2convert0: > Device '/dev/video4' does not support bt601 colorimetry > Additional debug info: > ../sys/v4l2/gstv4l2object.c(4032): gst_v4l2_object_set_format_full (): > /GstPipeline:pipeline0/v4l2convert:v4l2convert0: > Device wants 2:4:5:4 colorimetry > ERROR: pipeline doesn't want to preroll. > Setting pipeline to NULL ... > Caught SIGSEGV > exec gdb failed: No such file or directory > Spinning. Please run 'gdb gst-launch-1.0 217' to continue debugging, > Ctrl-C to quit, or Ctrl-\ to dump core. > > Is the Gstreamer pipeline above correct? Yes. Please try if the following patch makes it work: ----------8<---------- >From c45afcaf6fbef56a86dce19200c06df78718db60 Mon Sep 17 00:00:00 2001 From: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> Date: Mon, 18 Jan 2021 15:54:43 +0100 Subject: [PATCH] v4l2object: handle GST_VIDEO_TRANSFER_BT601 V4L2 makes no difference between the BT.601 and BT.709 transfer functions [1], but GStreamer does since 1.18 [2]. Adapt gst_v4l2_object_get_colorspace() and gst_v4l2_object_set_format_full(). [1] https://linuxtv.org/downloads/v4l-dvb-apis-new/userspace-api/v4l/colorspaces-details.html#colorspace-smpte-170m-v4l2-colorspace-smpte170m [2] https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/724 --- sys/v4l2/gstv4l2object.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/sys/v4l2/gstv4l2object.c b/sys/v4l2/gstv4l2object.c index ea4363e17303..b13216d75836 100644 --- a/sys/v4l2/gstv4l2object.c +++ b/sys/v4l2/gstv4l2object.c @@ -2334,7 +2334,7 @@ gst_v4l2_object_get_colorspace (struct v4l2_format *fmt, case V4L2_COLORSPACE_SMPTE170M: cinfo->range = GST_VIDEO_COLOR_RANGE_16_235; cinfo->matrix = GST_VIDEO_COLOR_MATRIX_BT601; - cinfo->transfer = GST_VIDEO_TRANSFER_BT709; + cinfo->transfer = GST_VIDEO_TRANSFER_BT601; cinfo->primaries = GST_VIDEO_COLOR_PRIMARIES_SMPTE170M; break; case V4L2_COLORSPACE_REC709: @@ -2463,6 +2463,8 @@ gst_v4l2_object_get_colorspace (struct v4l2_format *fmt, case V4L2_XFER_FUNC_709: if (colorspace == V4L2_COLORSPACE_BT2020 && fmt->fmt.pix.height >= 2160) cinfo->transfer = GST_VIDEO_TRANSFER_BT2020_12; + else if (colorspace == V4L2_COLORSPACE_SMPTE170M) + cinfo->transfer = GST_VIDEO_TRANSFER_BT601; else cinfo->transfer = GST_VIDEO_TRANSFER_BT709; break; @@ -3855,6 +3857,7 @@ gst_v4l2_object_set_format_full (GstV4l2Object * v4l2object, GstCaps * caps, case GST_VIDEO_TRANSFER_GAMMA10: transfer = V4L2_XFER_FUNC_NONE; break; + case GST_VIDEO_TRANSFER_BT601: case GST_VIDEO_TRANSFER_BT2020_12: case GST_VIDEO_TRANSFER_BT709: transfer = V4L2_XFER_FUNC_709; -- 2.20.1 ---------->8---------- This may not be the correct solution. GStreamer could keep choosing BT709 as told by V4L2, and use the new gst_video_color_transfer_is_equivalent() function to test for equivalence instead. regards Philipp
