diff options
Diffstat (limited to 'docs/manual.md')
| -rw-r--r-- | docs/manual.md | 132 |
1 files changed, 99 insertions, 33 deletions
diff --git a/docs/manual.md b/docs/manual.md index 69abae8..a68400e 100644 --- a/docs/manual.md +++ b/docs/manual.md @@ -12,7 +12,18 @@ Before installing `libuca` itself, you should install any drivers and SDKs needed to access the cameras you want to access through `libuca`. Now you have two options: install pre-built packages or build from source. -## Building from source +### Installing packages + +Packages for the core library and all plugins are currently provided for +openSUSE. To install them run `zypper`: + + sudo zypper in libuca-x.y.z-x86_64.rpm + sudo zypper in uca-plugin-*.rpm + +To install development files such as headers, you have to install the +`libuca-x.y.z-devel.rpm` package. + +### Building from source Building the library and installing from source is simple and straightforward. Make sure you have @@ -38,7 +49,8 @@ repository][repo], you also need Git: [repo]: http://ufo.kit.edu/repos/libuca.git/ -### Fetching the sources + +#### Fetching the sources Untar the distribution @@ -54,7 +66,7 @@ and create a new, empty build directory inside: mkdir build -### Configuring and building +#### Configuring and building Now you need to create the Makefile with CMake. Go into the build directory and point CMake to the `libuca` top-level directory: @@ -86,7 +98,7 @@ latter that 64 should be appended to any library paths. This is necessary on Linux distributions that expect 64-bit libraries in `/usr[/local]/lib64`. -### Building this manual +#### Building this manual Make sure you have [Pandoc][] installed. With Debian/Ubuntu this can be achieved with @@ -107,6 +119,7 @@ necessary header files: ~~~ {.c} #include <glib-object.h> +#include <uca-plugin-manager.h> #include <uca-camera.h> ~~~ @@ -116,6 +129,7 @@ Then you need to setup the type system: int main (int argc, char *argv[]) { + UcaPluginManager *manager; UcaCamera *camera; GError *error = NULL; /* this _must_ be set to NULL */ @@ -124,10 +138,12 @@ main (int argc, char *argv[]) Now you can instantiate new camera _objects_. Each camera is identified by a human-readable string, in this case we want to access any pco camera that is -supported by [libpco][]: +supported by [libpco][]. To instantiate a camera we have to create a plugin +manager first: ~~~ {.c} - camera = uca_camera_new ("pco", &error); + manager = uca_plugin_manager_new (); + camera = uca_plugin_manager_get_camera (manager, "pco", &error); ~~~ Errors are indicated with a returned value `NULL` and `error` set to a value @@ -241,6 +257,16 @@ The following cameras are supported: * Pylon * UFO Camera developed at KIT/IPE. +## Property documentation + +* [Basic camera properties][base-doc] +* [pco][pco-doc] +* [mock][mock-doc] + +[base-doc]: base.html +[pco-doc]: pco.html +[mock-doc]: mock.html + # More API @@ -252,38 +278,19 @@ communicate with the camera. Now we will go into more detail. We have already seen how to instantiate a camera object from a name. If you have more than one camera connected to a machine, you will most likely want the user decide which to use. To do so, you can enumerate all camera strings with -`uca_camera_get_types`: +`uca_plugin_manager_get_available_cameras`: ~~~ {.c} - gchar **types; + GList *types; - types = uca_camera_get_types (); + types = uca_camera_get_available_cameras (manager); - for (guint i = 0; types[i] != NULL; i++) - g_print ("%s\n", types[i]); + for (GList *it = g_list_first; it != NULL; it = g_list_next (it)) + g_print ("%s\n", (gchar *) it->data); - /* free the string array */ - g_strfreev (types); -~~~ - -If you _know_ which camera you want to use you can instantiate the sub-classed -camera object directly. In this case we create a pco-based camera: - -~~~ {.c} -#include <glib-object.h> -#include <uca/uca-camera-pco.h> - -int -main (int argc, char *argv[]) -{ - UcaPcoCamera *camera; - GError *error = NULL; - - g_type_init (); - camera = uca_pco_camera_new (&error); - g_object_unref (camera); - return 0; -} + /* free the strings and the list */ + g_list_foreach (types, (GFunc) g_free, NULL); + g_list_free (types); ~~~ [last section]: #first-look-at-the-api @@ -374,6 +381,37 @@ setup_async (UcaCamera *camera) } ~~~ + +# Bindings + +Since version 1.1, libuca generates GObject introspection meta data if +`g-ir-scanner` and `g-ir-compiler` can be found. When the XML description +`Uca-x.y.gir` and the typelib `Uca-x.y.typelib` are installed, GI-aware +languages can access libuca and create and modify cameras, for example in +Python: + +~~~ {.python} +from gi.repository import Uca + +pm = Uca.PluginManager() + +# List all cameras +print(pm.get_available_cameras()) + +# Load a camera +cam = pm.get_camera('pco') + +# You can read and write properties in two ways +cam.set_properties(exposure_time=0.05) +cam.props.roi_width = 1024 +~~~ + +Note, that the naming of classes and properties depends on the GI implementation +of the target language. For example with Python, the namespace prefix `uca_` +becomes the module name `Uca` and dashes separating property names become +underscores. + + # Integrating new cameras A new camera is integrated by [sub-classing][] `UcaCamera` and implement all @@ -381,6 +419,31 @@ virtual methods. The simplest way is to take the `mock` camera and rename all occurences. Note, that if you class is going to be called `FooBar`, the upper case variant is `FOO_BAR` and the lower case variant is `foo_bar`. +In order to fully implement a camera, you need to override at least the +following virtual methods: + +* `start_recording`: Take suitable actions so that a subsequent call to + `grab` delivers an image or blocks until one is exposed. +* `stop_recording`: Stop recording so that subsequent calls to `grab` + fail. +* `grab`: Return an image from the camera or block until one is ready. + +## Asynchronous operation + +When the camera supports asynchronous acquisition and announces it with a true +boolean value for `"transfer-asynchronously"`, a mechanism must be setup up +during `start_recording` so that for each new frame the grab func callback is +called. + +## Cameras with internal memory + +Cameras such as the pco.dimax record into their own on-board memory rather than +streaming directly to the host PC. In this case, both `start_recording` and +`stop_recording` initiate and end acquisition to the on-board memory. To +initiate a data transfer, the host calls `start_readout` which must be suitably +implemented. The actual data transfer happens either with `grab` or +asynchronously. + [sub-classing]: http://developer.gnome.org/gobject/stable/howto-gobject.html @@ -426,3 +489,6 @@ grabbing time: # The GObject Tango device [TODO: Get more information from Volker Kaiser and/or Mihael Koep] + + +# ChangeLog |