From e9a876acc6d3a3d8ce1cfc99e4cbcf1c6122d591 Mon Sep 17 00:00:00 2001 From: Hou Qi Date: Mon, 16 Dec 2024 13:30:44 +0900 Subject: gstreamer: keep same transfer with that in negotiated caps The conversions back and forth between GStreamer colorimetry and libcamera color space are not invariant for the bt601 colorimetry. The reason is that Rec709 transfer function defined in GStreamer as GST_VIDEO_TRANSFER_BT709 (5), is to be replaced by its alias GST_VIDEO_TRANSFER_BT601 (16) only for the case of bt601 (aka 2:4:16:4) colorimetry - see [1]. Currently the composition of the GStreamer/libcamera conversions: colorimetry_from_colorspace (colorspace_from_colorimetry (bt601)) returns 2:4:5:4 instead of the expected 2:4:16:4 (bt601). This causes negotiation error when the downstream element explicitly expects bt601 colorimetry. Minimal example to reproduce the issue is with a pipeline handler that do not set the optional color space in the stream configuration, for instance vimc or imx8-isi: export LIBCAMERA_PIPELINES_MATCH_LIST="vimc,imx8-isi" gst-launch-1.0 -v libcamerasrc ! video/x-raw,colorimetry=bt601 ! fakesink Above pipeline fails to start. This change memorizes downstream required transfer function when mapped libcamera transfer is Rec709 in gst_libcamera_configure_stream_from_caps(), and restores the transfer function in gst_libcamera_stream_formats_to_caps(). [1] https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/724 Bug: https://bugs.libcamera.org/show_bug.cgi?id=150 Signed-off-by: Hou Qi Reviewed-by: Laurent Pinchart Reviewed-by: Nicolas Dufresne Signed-off-by: Laurent Pinchart --- src/gstreamer/gstlibcamera-utils.cpp | 20 ++++++++++++-------- src/gstreamer/gstlibcamera-utils.h | 5 +++-- src/gstreamer/gstlibcamerasrc.cpp | 6 ++++-- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp index 732987ef..a466b305 100644 --- a/src/gstreamer/gstlibcamera-utils.cpp +++ b/src/gstreamer/gstlibcamera-utils.cpp @@ -85,7 +85,7 @@ static struct { }; static GstVideoColorimetry -colorimetry_from_colorspace(const ColorSpace &colorSpace) +colorimetry_from_colorspace(const ColorSpace &colorSpace, GstVideoTransferFunction transfer) { GstVideoColorimetry colorimetry; @@ -113,6 +113,8 @@ colorimetry_from_colorspace(const ColorSpace &colorSpace) break; case ColorSpace::TransferFunction::Rec709: colorimetry.transfer = GST_VIDEO_TRANSFER_BT709; + if (transfer != GST_VIDEO_TRANSFER_UNKNOWN) + colorimetry.transfer = transfer; break; } @@ -144,7 +146,8 @@ colorimetry_from_colorspace(const ColorSpace &colorSpace) } static std::optional -colorspace_from_colorimetry(const GstVideoColorimetry &colorimetry) +colorspace_from_colorimetry(const GstVideoColorimetry &colorimetry, + GstVideoTransferFunction *transfer) { std::optional colorspace = ColorSpace::Raw; @@ -188,6 +191,7 @@ colorspace_from_colorimetry(const GstVideoColorimetry &colorimetry) case GST_VIDEO_TRANSFER_BT2020_12: case GST_VIDEO_TRANSFER_BT709: colorspace->transferFunction = ColorSpace::TransferFunction::Rec709; + *transfer = colorimetry.transfer; break; default: GST_WARNING("Colorimetry transfer function %d not mapped in gstlibcamera", @@ -379,7 +383,8 @@ gst_libcamera_stream_formats_to_caps(const StreamFormats &formats) } GstCaps * -gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg) +gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg, + GstVideoTransferFunction transfer) { GstCaps *caps = gst_caps_new_empty(); GstStructure *s = bare_structure_from_format(stream_cfg.pixelFormat); @@ -390,7 +395,7 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg nullptr); if (stream_cfg.colorSpace) { - GstVideoColorimetry colorimetry = colorimetry_from_colorspace(stream_cfg.colorSpace.value()); + GstVideoColorimetry colorimetry = colorimetry_from_colorspace(stream_cfg.colorSpace.value(), transfer); g_autofree gchar *colorimetry_str = gst_video_colorimetry_to_string(&colorimetry); if (colorimetry_str) @@ -405,9 +410,8 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg return caps; } -void -gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, - GstCaps *caps) +void gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, + GstCaps *caps, GstVideoTransferFunction *transfer) { GstVideoFormat gst_format = pixel_format_to_gst_format(stream_cfg.pixelFormat); guint i; @@ -495,7 +499,7 @@ gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, if (!gst_video_colorimetry_from_string(&colorimetry, colorimetry_str)) g_critical("Invalid colorimetry %s", colorimetry_str); - stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry); + stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry, transfer); } } diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h index cab1c814..4978987c 100644 --- a/src/gstreamer/gstlibcamera-utils.h +++ b/src/gstreamer/gstlibcamera-utils.h @@ -16,9 +16,10 @@ #include GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &formats); -GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg); +GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg, + GstVideoTransferFunction transfer); void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg, - GstCaps *caps); + GstCaps *caps, GstVideoTransferFunction *transfer); void gst_libcamera_get_framerate_from_caps(GstCaps *caps, GstStructure *element_caps); void gst_libcamera_clamp_and_set_frameduration(libcamera::ControlList &controls, const libcamera::ControlInfoMap &camera_controls, diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp index 8efa25f4..5e9e843d 100644 --- a/src/gstreamer/gstlibcamerasrc.cpp +++ b/src/gstreamer/gstlibcamerasrc.cpp @@ -433,6 +433,8 @@ static bool gst_libcamera_src_negotiate(GstLibcameraSrc *self) { GstLibcameraSrcState *state = self->state; + std::vector transfer(state->srcpads_.size(), + GST_VIDEO_TRANSFER_UNKNOWN); g_autoptr(GstStructure) element_caps = gst_structure_new_empty("caps"); @@ -448,7 +450,7 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self) /* Fixate caps and configure the stream. */ caps = gst_caps_make_writable(caps); - gst_libcamera_configure_stream_from_caps(stream_cfg, caps); + gst_libcamera_configure_stream_from_caps(stream_cfg, caps, &transfer[i]); gst_libcamera_get_framerate_from_caps(caps, element_caps); } @@ -476,7 +478,7 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self) GstPad *srcpad = state->srcpads_[i]; const StreamConfiguration &stream_cfg = state->config_->at(i); - g_autoptr(GstCaps) caps = gst_libcamera_stream_configuration_to_caps(stream_cfg); + g_autoptr(GstCaps) caps = gst_libcamera_stream_configuration_to_caps(stream_cfg, transfer[i]); gst_libcamera_framerate_to_caps(caps, element_caps); if (!gst_pad_push_event(srcpad, gst_event_new_caps(caps))) -- cgit v1.2.1