diff options
| -rw-r--r-- | Documentation/guides/application-developer.rst | 12 | ||||
| -rw-r--r-- | src/apps/cam/camera_session.cpp | 11 | ||||
| -rw-r--r-- | src/gstreamer/gstlibcamerasrc.cpp | 5 |
3 files changed, 18 insertions, 10 deletions
diff --git a/Documentation/guides/application-developer.rst b/Documentation/guides/application-developer.rst index 9a9905b1..92e2a373 100644 --- a/Documentation/guides/application-developer.rst +++ b/Documentation/guides/application-developer.rst @@ -116,19 +116,21 @@ available. .. code:: cpp - if (cm->cameras().empty()) { + auto cameras = cm->cameras(); + if (cameras.empty()) { std::cout << "No cameras were identified on the system." << std::endl; cm->stop(); return EXIT_FAILURE; } - std::string cameraId = cm->cameras()[0]->id(); - camera = cm->get(cameraId); + std::string cameraId = cameras[0]->id(); + auto camera = cm->get(cameraId); /* - * Note that is equivalent to: - * camera = cm->cameras()[0]; + * Note that `camera` may not compare equal to `cameras[0]`. + * In fact, it might simply be a `nullptr`, as the particular + * device might have disappeared (and reappeared) in the meantime. */ Once a camera has been selected an application needs to acquire an exclusive diff --git a/src/apps/cam/camera_session.cpp b/src/apps/cam/camera_session.cpp index f13355ba..097dc479 100644 --- a/src/apps/cam/camera_session.cpp +++ b/src/apps/cam/camera_session.cpp @@ -39,9 +39,14 @@ CameraSession::CameraSession(CameraManager *cm, { char *endptr; unsigned long index = strtoul(cameraId.c_str(), &endptr, 10); - if (*endptr == '\0' && index > 0 && index <= cm->cameras().size()) - camera_ = cm->cameras()[index - 1]; - else + + if (*endptr == '\0' && index > 0) { + auto cameras = cm->cameras(); + if (index <= cameras.size()) + camera_ = cameras[index - 1]; + } + + if (!camera_) camera_ = cm->get(cameraId); if (!camera_) { diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp index 6a95b6af..9680d809 100644 --- a/src/gstreamer/gstlibcamerasrc.cpp +++ b/src/gstreamer/gstlibcamerasrc.cpp @@ -385,13 +385,14 @@ gst_libcamera_src_open(GstLibcameraSrc *self) return false; } } else { - if (cm->cameras().empty()) { + auto cameras = cm->cameras(); + if (cameras.empty()) { GST_ELEMENT_ERROR(self, RESOURCE, NOT_FOUND, ("Could not find any supported camera on this system."), ("libcamera::CameraMananger::cameras() is empty")); return false; } - cam = cm->cameras()[0]; + cam = cameras[0]; } GST_INFO_OBJECT(self, "Using camera '%s'", cam->id().c_str()); |