The color matrix is used to convert between Y'PbPr and non-linear RGB (R'G'B') unknown matrix identity matrix FCC color matrix ITU-R BT.709 color matrix ITU-R BT.601 color matrix SMPTE 240M color matrix ITU-R BT.2020 color matrix. Since: 1.6. The color primaries define the how to transform linear RGB values to and from the CIE XYZ colorspace. unknown color primaries BT709 primaries BT470M primaries BT470BG primaries SMPTE170M primaries SMPTE240M primaries Generic film BT2020 primaries. Since: 1.6. Adobe RGB primaries. Since: 1.8 Possible color range values. These constants are defined for 8 bit color values and can be scaled for other bit depths. unknown range [0..255] for 8 bit components [16..235] for 8 bit components. Chroma has [16..240] range. Structure describing the color info. Parse the colorimetry string and update `self` with the parsed values. ## `color` a colorimetry string # Returns `true` if `color` points to valid colorimetry info. Compare the 2 colorimetry sets for equality ## `other` another `VideoColorimetry` # Returns `true` if `self` and `other` are equal. Check if the colorimetry information in `info` matches that of the string `color`. ## `color` a colorimetry string # Returns `true` if `color` conveys the same colorimetry info as the color information in `info`. Make a string representation of `self`. # Returns a string representation of `self`. Field order of interlaced content. This is only valid for interlace-mode=interleaved and not interlace-mode=mixed. In the case of mixed or GST_VIDEO_FIELD_ORDER_UNKOWN, the field order is signalled via buffer flags. unknown field order for interlaced content. The actual field order is signalled via buffer flags. top field is first bottom field is first Feature: `v1_12` Enum value describing the most common video formats. Unknown or unset video format id Encoded video format. Only ever use that in caps for special video formats in combination with non-system memory GstCapsFeatures where it does not make sense to specify a real video format. planar 4:2:0 YUV planar 4:2:0 YVU (like I420 but UV planes swapped) packed 4:2:2 YUV (Y0-U0-Y1-V0 Y2-U2-Y3-V2 Y4 ...) packed 4:2:2 YUV (U0-Y0-V0-Y1 U2-Y2-V2-Y3 U4 ...) packed 4:4:4 YUV with alpha channel (A0-Y0-U0-V0 ...) sparse rgb packed into 32 bit, space last sparse reverse rgb packed into 32 bit, space last sparse rgb packed into 32 bit, space first sparse reverse rgb packed into 32 bit, space first rgb with alpha channel last reverse rgb with alpha channel last rgb with alpha channel first reverse rgb with alpha channel first rgb reverse rgb planar 4:1:1 YUV planar 4:2:2 YUV packed 4:2:2 YUV (Y0-V0-Y1-U0 Y2-V2-Y3-U2 Y4 ...) planar 4:4:4 YUV packed 4:2:2 10-bit YUV, complex format packed 4:2:2 16-bit YUV, Y0-U0-Y1-V1 order planar 4:2:0 YUV with interleaved UV plane planar 4:2:0 YUV with interleaved VU plane 8-bit grayscale 16-bit grayscale, most significant byte first 16-bit grayscale, least significant byte first packed 4:4:4 YUV (Y-U-V ...) rgb 5-6-5 bits per component reverse rgb 5-6-5 bits per component rgb 5-5-5 bits per component reverse rgb 5-5-5 bits per component packed 10-bit 4:2:2 YUV (U0-Y0-V0-Y1 U2-Y2-V2-Y3 U4 ...) planar 4:4:2:0 AYUV 8-bit paletted RGB planar 4:1:0 YUV planar 4:1:0 YUV (like YUV9 but UV planes swapped) packed 4:1:1 YUV (Cb-Y0-Y1-Cr-Y2-Y3 ...) rgb with alpha channel first, 16 bits per channel packed 4:4:4 YUV with alpha channel, 16 bits per channel (A0-Y0-U0-V0 ...) packed 4:4:4 RGB, 10 bits per channel planar 4:2:0 YUV, 10 bits per channel planar 4:2:0 YUV, 10 bits per channel planar 4:2:2 YUV, 10 bits per channel planar 4:2:2 YUV, 10 bits per channel planar 4:4:4 YUV, 10 bits per channel (Since: 1.2) planar 4:4:4 YUV, 10 bits per channel (Since: 1.2) planar 4:4:4 RGB, 8 bits per channel (Since: 1.2) planar 4:4:4 RGB, 10 bits per channel (Since: 1.2) planar 4:4:4 RGB, 10 bits per channel (Since: 1.2) planar 4:2:2 YUV with interleaved UV plane (Since: 1.2) planar 4:4:4 YUV with interleaved UV plane (Since: 1.2) NV12 with 64x32 tiling in zigzag pattern (Since: 1.4) planar 4:4:2:0 YUV, 10 bits per channel (Since: 1.6) planar 4:4:2:0 YUV, 10 bits per channel (Since: 1.6) planar 4:4:2:2 YUV, 10 bits per channel (Since: 1.6) planar 4:4:2:2 YUV, 10 bits per channel (Since: 1.6) planar 4:4:4:4 YUV, 10 bits per channel (Since: 1.6) planar 4:4:4:4 YUV, 10 bits per channel (Since: 1.6) planar 4:2:2 YUV with interleaved VU plane (Since: 1.6) planar 4:2:0 YUV with interleaved UV plane, 10 bits per channel (Since: 1.10) planar 4:2:0 YUV with interleaved UV plane, 10 bits per channel (Since: 1.10) packed 4:4:4 YUV (U-Y-V ...) (Since 1.10) packed 4:2:2 YUV (V0-Y0-U0-Y1 V2-Y2-U2-Y3 V4 ...) planar 4:4:4:4 ARGB, 8 bits per channel (Since: 1.12) planar 4:4:4:4 ARGB, 10 bits per channel (Since: 1.12) planar 4:4:4:4 ARGB, 10 bits per channel (Since: 1.12) planar 4:4:4 RGB, 12 bits per channel (Since: 1.12) planar 4:4:4 RGB, 12 bits per channel (Since: 1.12) planar 4:4:4:4 ARGB, 12 bits per channel (Since: 1.12) planar 4:4:4:4 ARGB, 12 bits per channel (Since: 1.12) planar 4:2:0 YUV, 12 bits per channel (Since: 1.12) planar 4:2:0 YUV, 12 bits per channel (Since: 1.12) planar 4:2:2 YUV, 12 bits per channel (Since: 1.12) planar 4:2:2 YUV, 12 bits per channel (Since: 1.12) planar 4:4:4 YUV, 12 bits per channel (Since: 1.12) planar 4:4:4 YUV, 12 bits per channel (Since: 1.12) Information for a video format. A video frame obtained from `VideoFrame::map` Copy the contents from `src` to `self`. ## `src` a `VideoFrame` # Returns TRUE if the contents could be copied. Copy the plane with index `plane` from `src` to `self`. ## `src` a `VideoFrame` ## `plane` a plane # Returns TRUE if the contents could be copied. Use `info` and `buffer` to fill in the values of `self`. `self` is usually allocated on the stack, and you will pass the address to the `VideoFrame` structure allocated on the stack; `VideoFrame::map` will then fill in the structures with the various video-specific information you need to access the pixels of the video buffer. You can then use accessor macros such as GST_VIDEO_FRAME_COMP_DATA(), GST_VIDEO_FRAME_PLANE_DATA(), GST_VIDEO_FRAME_COMP_STRIDE(), GST_VIDEO_FRAME_PLANE_STRIDE() etc. to get to the pixels. ```C GstVideoFrame vframe; ... // set RGB pixels to black one at a time if (gst_video_frame_map (&vframe, video_info, video_buffer, GST_MAP_WRITE)) { guint8 *pixels = GST_VIDEO_FRAME_PLANE_DATA (vframe, 0); guint stride = GST_VIDEO_FRAME_PLANE_STRIDE (vframe, 0); guint pixel_stride = GST_VIDEO_FRAME_COMP_PSTRIDE (vframe, 0); for (h = 0; h < height; ++h) { for (w = 0; w < width; ++w) { guint8 *pixel = pixels + h * stride + w * pixel_stride; memset (pixel, 0, pixel_stride); } } gst_video_frame_unmap (&vframe); } ... ``` All video planes of `buffer` will be mapped and the pointers will be set in `self`->data. The purpose of this function is to make it easy for you to get to the video pixels in a generic way, without you having to worry too much about details such as whether the video data is allocated in one contiguous memory chunk or multiple memory chunks (e.g. one for each plane); or if custom strides and custom plane offsets are used or not (as signalled by GstVideoMeta on each buffer). This function will just fill the `VideoFrame` structure with the right values and if you use the accessor macros everything will just work and you can access the data easily. It also maps the underlying memory chunks for you. ## `info` a `VideoInfo` ## `buffer` the buffer to map ## `flags` `gst::MapFlags` # Returns `true` on success. Use `info` and `buffer` to fill in the values of `self` with the video frame information of frame `id`. When `id` is -1, the default frame is mapped. When `id` != -1, this function will return `false` when there is no GstVideoMeta with that id. All video planes of `buffer` will be mapped and the pointers will be set in `self`->data. ## `info` a `VideoInfo` ## `buffer` the buffer to map ## `id` the frame id to map ## `flags` `gst::MapFlags` # Returns `true` on success. Unmap the memory previously mapped with gst_video_frame_map. Information describing image properties. This information can be filled in from GstCaps with `VideoInfo::from_caps`. The information is also used to store the specific video info when mapping a video frame with `VideoFrame::map`. Use the provided macros to access the info in this structure. Allocate a new `VideoInfo` that is also initialized with `VideoInfo::init`. # Returns a new `VideoInfo`. free with `VideoInfo::free`. Adjust the offset and stride fields in `self` so that the padding and stride alignment in `align` is respected. Extra padding will be added to the right side when stride alignment padding is required and `align` will be updated with the new padding values. ## `align` alignment parameters # Returns `false` if alignment could not be applied, e.g. because the size of a frame can't be represented as a 32 bit integer (Since: 1.12) Converts among various `gst::Format` types. This function handles GST_FORMAT_BYTES, GST_FORMAT_TIME, and GST_FORMAT_DEFAULT. For raw video, GST_FORMAT_DEFAULT corresponds to video frames. This function can be used to handle pad queries of the type GST_QUERY_CONVERT. ## `src_format` `gst::Format` of the `src_value` ## `src_value` value to convert ## `dest_format` `gst::Format` of the `dest_value` ## `dest_value` pointer to destination value # Returns TRUE if the conversion was successful. Copy a GstVideoInfo structure. # Returns a new `VideoInfo`. free with gst_video_info_free. Free a GstVideoInfo structure previously allocated with `VideoInfo::new` or `VideoInfo::copy`. Parse `caps` and update `self`. ## `caps` a `gst::Caps` # Returns TRUE if `caps` could be parsed Initialize `self` with default values. Compares two `VideoInfo` and returns whether they are equal or not ## `other` a `VideoInfo` # Returns `true` if `self` and `other` are equal, else `false`. Set the default info for a video frame of `format` and `width` and `height`. Note: This initializes `self` first, no values are preserved. This function does not set the offsets correctly for interlaced vertically subsampled formats. ## `format` the format ## `width` a width ## `height` a height # Returns `false` if the returned video info is invalid, e.g. because the size of a frame can't be represented as a 32 bit integer (Since: 1.12) Convert the values of `self` into a `gst::Caps`. # Returns a new `gst::Caps` containing the info of `self`. The possible values of the `VideoInterlaceMode` describing the interlace mode of the stream. all frames are progressive 2 fields are interleaved in one video frame. Extra buffer flags describe the field order. frames contains both interlaced and progressive video, the buffer flags describe the frame and fields. 2 fields are stored in one buffer, use the frame ID to get access to the required field. For multiview (the 'views' property > 1) the fields of view N can be found at frame ID (N * 2) and (N * 2) + 1. Each field has only half the amount of lines as noted in the height property. This mode requires multiple GstVideoMeta metadata to describe the fields. All possible stereoscopic 3D and multiview representations. In conjunction with `VideoMultiviewFlags`, describes how multiview content is being transported in the stream. A special value indicating no multiview information. Used in GstVideoInfo and other places to indicate that no specific multiview handling has been requested or provided. This value is never carried on caps. All frames are monoscopic. All frames represent a left-eye view. All frames represent a right-eye view. Left and right eye views are provided in the left and right half of the frame respectively. Left and right eye views are provided in the left and right half of the frame, but have been sampled using quincunx method, with half-pixel offset between the 2 views. Alternating vertical columns of pixels represent the left and right eye view respectively. Alternating horizontal rows of pixels represent the left and right eye view respectively. The top half of the frame contains the left eye, and the bottom half the right eye. Pixels are arranged with alternating pixels representing left and right eye views in a checkerboard fashion. Left and right eye views are provided in separate frames alternately. Multiple independent views are provided in separate frames in sequence. This method only applies to raw video buffers at the moment. Specific view identification is via the `GstVideoMultiviewMeta` and `VideoMeta`(s) on raw video buffers. Multiple views are provided as separate `gst::Memory` framebuffers attached to each `gst::Buffer`, described by the `GstVideoMultiviewMeta` and `VideoMeta`(s) The `VideoOverlay` interface is used for 2 main purposes : * To get a grab on the Window where the video sink element is going to render. This is achieved by either being informed about the Window identifier that the video sink element generated, or by forcing the video sink element to use a specific Window identifier for rendering. * To force a redrawing of the latest video frame the video sink element displayed on the Window. Indeed if the `gst::Pipeline` is in `gst::State::Paused` state, moving the Window around will damage its content. Application developers will want to handle the Expose events themselves and force the video sink element to refresh the Window's content. Using the Window created by the video sink is probably the simplest scenario, in some cases, though, it might not be flexible enough for application developers if they need to catch events such as mouse moves and button clicks. Setting a specific Window identifier on the video sink element is the most flexible solution but it has some issues. Indeed the application needs to set its Window identifier at the right time to avoid internal Window creation from the video sink element. To solve this issue a `gst::Message` is posted on the bus to inform the application that it should set the Window identifier immediately. Here is an example on how to do that correctly: ```text static GstBusSyncReply create_window (GstBus * bus, GstMessage * message, GstPipeline * pipeline) { // ignore anything but 'prepare-window-handle' element messages if (!gst_is_video_overlay_prepare_window_handle_message (message)) return GST_BUS_PASS; win = XCreateSimpleWindow (disp, root, 0, 0, 320, 240, 0, 0, 0); XSetWindowBackgroundPixmap (disp, win, None); XMapRaised (disp, win); XSync (disp, FALSE); gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message)), win); gst_message_unref (message); return GST_BUS_DROP; } ... int main (int argc, char **argv) { ... bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); gst_bus_set_sync_handler (bus, (GstBusSyncHandler) create_window, pipeline, NULL); ... } ``` ## Two basic usage scenarios There are two basic usage scenarios: in the simplest case, the application uses `playbin` or `plasink` or knows exactly what particular element is used for video output, which is usually the case when the application creates the videosink to use (e.g. `xvimagesink`, `ximagesink`, etc.) itself; in this case, the application can just create the videosink element, create and realize the window to render the video on and then call `VideoOverlay::set_window_handle` directly with the XID or native window handle, before starting up the pipeline. As `playbin` and `playsink` implement the video overlay interface and proxy it transparently to the actual video sink even if it is created later, this case also applies when using these elements. In the other and more common case, the application does not know in advance what GStreamer video sink element will be used for video output. This is usually the case when an element such as `autovideosink` is used. In this case, the video sink element itself is created asynchronously from a GStreamer streaming thread some time after the pipeline has been started up. When that happens, however, the video sink will need to know right then whether to render onto an already existing application window or whether to create its own window. This is when it posts a prepare-window-handle message, and that is also why this message needs to be handled in a sync bus handler which will be called from the streaming thread directly (because the video sink will need an answer right then). As response to the prepare-window-handle element message in the bus sync handler, the application may use `VideoOverlay::set_window_handle` to tell the video sink to render onto an existing window surface. At this point the application should already have obtained the window handle / XID, so it just needs to set it. It is generally not advisable to call any GUI toolkit functions or window system functions from the streaming thread in which the prepare-window-handle message is handled, because most GUI toolkits and windowing systems are not thread-safe at all and a lot of care would be required to co-ordinate the toolkit and window system calls of the different threads (Gtk+ users please note: prior to Gtk+ 2.18 GDK_WINDOW_XID() was just a simple structure access, so generally fine to do within the bus sync handler; this macro was changed to a function call in Gtk+ 2.18 and later, which is likely to cause problems when called from a sync handler; see below for a better approach without GDK_WINDOW_XID() used in the callback). ## GstVideoOverlay and Gtk+ ```text #include <gst/video/videooverlay.h> #include <gtk/gtk.h> #ifdef GDK_WINDOWING_X11 #include <gdk/gdkx.h> // for GDK_WINDOW_XID #endif #ifdef GDK_WINDOWING_WIN32 #include <gdk/gdkwin32.h> // for GDK_WINDOW_HWND #endif ... static guintptr video_window_handle = 0; ... static GstBusSyncReply bus_sync_handler (GstBus * bus, GstMessage * message, gpointer user_data) { // ignore anything but 'prepare-window-handle' element messages if (!gst_is_video_overlay_prepare_window_handle_message (message)) return GST_BUS_PASS; if (video_window_handle != 0) { GstVideoOverlay *overlay; // GST_MESSAGE_SRC (message) will be the video sink element overlay = GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message)); gst_video_overlay_set_window_handle (overlay, video_window_handle); } else { g_warning ("Should have obtained video_window_handle by now!"); } gst_message_unref (message); return GST_BUS_DROP; } ... static void video_widget_realize_cb (GtkWidget * widget, gpointer data) { #if GTK_CHECK_VERSION(2,18,0) // Tell Gtk+/Gdk to create a native window for this widget instead of // drawing onto the parent widget. // This is here just for pedagogical purposes, GDK_WINDOW_XID will call // it as well in newer Gtk versions if (!gdk_window_ensure_native (widget->window)) g_error ("Couldn't create native window needed for GstVideoOverlay!"); #endif #ifdef GDK_WINDOWING_X11 { gulong xid = GDK_WINDOW_XID (gtk_widget_get_window (video_window)); video_window_handle = xid; } #endif #ifdef GDK_WINDOWING_WIN32 { HWND wnd = GDK_WINDOW_HWND (gtk_widget_get_window (video_window)); video_window_handle = (guintptr) wnd; } #endif } ... int main (int argc, char **argv) { GtkWidget *video_window; GtkWidget *app_window; ... app_window = gtk_window_new (GTK_WINDOW_TOPLEVEL); ... video_window = gtk_drawing_area_new (); g_signal_connect (video_window, "realize", G_CALLBACK (video_widget_realize_cb), NULL); gtk_widget_set_double_buffered (video_window, FALSE); ... // usually the video_window will not be directly embedded into the // application window like this, but there will be many other widgets // and the video window will be embedded in one of them instead gtk_container_add (GTK_CONTAINER (ap_window), video_window); ... // show the GUI gtk_widget_show_all (app_window); // realize window now so that the video window gets created and we can // obtain its XID/HWND before the pipeline is started up and the videosink // asks for the XID/HWND of the window to render onto gtk_widget_realize (video_window); // we should have the XID/HWND now g_assert (video_window_handle != 0); ... // set up sync handler for setting the xid once the pipeline is started bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bus_sync_handler, NULL, NULL); gst_object_unref (bus); ... gst_element_set_state (pipeline, GST_STATE_PLAYING); ... } ``` ## GstVideoOverlay and Qt ```text #include <glib.h> #include <gst/gst.h> #include <gst/video/videooverlay.h> #include <QApplication> #include <QTimer> #include <QWidget> int main(int argc, char *argv[]) { if (!g_thread_supported ()) g_thread_init (NULL); gst_init (&argc, &argv); QApplication app(argc, argv); app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit ())); // prepare the pipeline GstElement *pipeline = gst_pipeline_new ("xvoverlay"); GstElement *src = gst_element_factory_make ("videotestsrc", NULL); GstElement *sink = gst_element_factory_make ("xvimagesink", NULL); gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL); gst_element_link (src, sink); // prepare the ui QWidget window; window.resize(320, 240); window.show(); WId xwinid = window.winId(); gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid); // run the pipeline GstStateChangeReturn sret = gst_element_set_state (pipeline, GST_STATE_PLAYING); if (sret == GST_STATE_CHANGE_FAILURE) { gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); // Exit application QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit())); } int ret = app.exec(); window.hide(); gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); return ret; } ``` # Implements [`VideoOverlayExt`](trait.VideoOverlayExt.html) Trait containing all `VideoOverlay` methods. # Implementors [`VideoOverlay`](struct.VideoOverlay.html) Tell an overlay that it has been exposed. This will redraw the current frame in the drawable even if the pipeline is PAUSED. This will post a "have-window-handle" element message on the bus. This function should only be used by video overlay plugin developers. ## `handle` a platform-specific handle referencing the window Tell an overlay that it should handle events from the window system. These events are forwarded upstream as navigation events. In some window system, events are not propagated in the window hierarchy if a client is listening for them. This method allows you to disable events handling completely from the `VideoOverlay`. ## `handle_events` a `gboolean` indicating if events should be handled or not. This will post a "prepare-window-handle" element message on the bus to give applications an opportunity to call `VideoOverlay::set_window_handle` before a plugin creates its own window. This function should only be used by video overlay plugin developers. Configure a subregion as a video target within the window set by `VideoOverlay::set_window_handle`. If this is not used or not supported the video will fill the area of the window set as the overlay to 100%. By specifying the rectangle, the video can be overlayed to a specific region of that window only. After setting the new rectangle one should call `VideoOverlay::expose` to force a redraw. To unset the region pass -1 for the `width` and `height` parameters. This method is needed for non fullscreen video overlay in UI toolkits that do not support subwindows. ## `x` the horizontal offset of the render area inside the window ## `y` the vertical offset of the render area inside the window ## `width` the width of the render area inside the window ## `height` the height of the render area inside the window # Returns `false` if not supported by the sink. This will call the video overlay's set_window_handle method. You should use this method to tell to an overlay to display video output to a specific window (e.g. an XWindow on X11). Passing 0 as the `handle` will tell the overlay to stop using that window and create an internal one. ## `handle` a handle referencing the window. Enum value describing the available tiling modes. Unknown or unset tile mode Every four adjacent blocks - two horizontally and two vertically are grouped together and are located in memory in Z or flipped Z order. In case of odd rows, the last row of blocks is arranged in linear order. The video transfer function defines the formula for converting between non-linear RGB (R'G'B') and linear RGB unknown transfer function linear RGB, gamma 1.0 curve Gamma 1.8 curve Gamma 2.0 curve Gamma 2.2 curve Gamma 2.2 curve with a linear segment in the lower range Gamma 2.2 curve with a linear segment in the lower range Gamma 2.4 curve with a linear segment in the lower range Gamma 2.8 curve Logarithmic transfer characteristic 100:1 range Logarithmic transfer characteristic 316.22777:1 range Gamma 2.2 curve with a linear segment in the lower range. Used for BT.2020 with 12 bits per component. Since: 1.6. Gamma 2.19921875. Since: 1.8