diff options
| -rw-r--r-- | src/v4l2/v4l2_compat_manager.cpp | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp index 0f7575c5..5e8cdb4f 100644 --- a/src/v4l2/v4l2_compat_manager.cpp +++ b/src/v4l2/v4l2_compat_manager.cpp @@ -24,6 +24,7 @@ #include <libcamera/camera.h> #include <libcamera/camera_manager.h> +#include <libcamera/property_ids.h> #include "v4l2_camera_file.h" @@ -113,14 +114,35 @@ int V4L2CompatManager::getCameraIndex(int fd) if (ret < 0) return -1; - std::shared_ptr<Camera> target = cm_->get(statbuf.st_rdev); - if (!target) - return -1; + const dev_t devnum = statbuf.st_rdev; + /* + * Iterate each known camera and identify if it reports this nodes + * device number in its list of SystemDevices. + */ auto cameras = cm_->cameras(); for (auto [index, camera] : utils::enumerate(cameras)) { - if (camera == target) - return index; + Span<const int64_t> devices = camera->properties() + .get(properties::SystemDevices) + .value_or(Span<int64_t>{}); + + /* + * While there may be multiple cameras that could reference the + * same device node, we take a first match as a best effort for + * now. + * + * \todo Each camera can be accessed through any of the video + * device nodes that it uses. This may confuse applications. + * Consider reworking the V4L2 adaptation layer to instead + * expose each Camera instance through a single video device + * node (with a consistent and stable mapping). The other + * device nodes could possibly be hidden from the application + * by intercepting additional calls to the C library. + */ + for (const int64_t dev : devices) { + if (dev == static_cast<int64_t>(devnum)) + return index; + } } return -1; |