Frequently Asked Questions¶
- What is libcamera?
libcamera is an open source camera stack for many platforms with a core userspace library, and support from the Linux kernel APIs and drivers already in place. It aims to control the complexity of embedded camera hardware by providing an intuitive API and method of separating untrusted vendor code from the open source core.
libcamera aims to encourage the development of new embedded camera applications by limiting the complexity that developers have to deal with. The interface is designed around the way that modern embedded camera hardware works.
- What is the correct way to display the name ‘libcamera’?
- libcamera, is always in lowercase. In titles, or at the beginning of sentences.
- How is libcamera different from V4L2?
- We see libcamera as a continuation of V4L2. One that can more easily handle the recent advances in hardware design. As embedded cameras have developed, all of the complexity has been pushed on to the developers. With libcamera, all of that complexity is simplified and a single model is presented to application developers.
- Does this mean the camera stack is completely open?
- libcamera is open-source friendly which means all of libcamera itself is open source. libcamera uses a plugin system for Image Processing Algorithms (IPA) which are built as dynamically-linked shared objects, and are loaded at run-time. Open-source modules are identified based on digital signatures, while closed-source modules are isolated inside a Sandbox environment with restricted access to the system, reducing the impact of untrusted binary blobs.
- libcamera has been described as “the MESA of the camera stack”. What does that mean?
- Mesa provides powerful high-level APIs to applications and implements device-specific code in userspace to support the implementation. libcamera provides high-level APIs that handle device-specific code in userspace to simplify development for application developers.
- Which devices (pipeline-handlers) are supported?
- Currently supported platforms include the Intel IPU3 (selected devices only), NXP i.MX7, Raspberry Pi 3 and 4, RockChip RK3399, as well as UVC webcams and the VIMC virtual test device.
- I have an Intel™ based laptop or tablet with an IPU3 running Windows™. Can I use libcamera to run my Webcam?
- Currently, on selected Microsoft Surface™ devices only, with some effort. The ACPI tables created for those devices are not compatible with the Linux drivers, and as such the camera sensors can not be correctly identified on those platforms. The linux-surface community and the libcamera project are cooperating to progresss on the kernel side to address this issue, with part of the support merged in v5.12, and active ongoing development for the remaining problems. You can track the status in the linux-surface project on GitHub.
- What role does the Pipeline Handler play?
- The Pipeline Handlers are used for managing any device specific code for a given platform. A ‘Simple Pipeline Handler’ is under development which will support a range of simplistic platforms with a common generic handler.
- Can I use libcamera to access photos on digital cameras?
- No, libcamera is a library for controlling embedded camera hardware, it’s not an application for accessing photos and has no relationship to gphoto2. libcamera supports internal cameras designed for point-and-shoot still image and video capture and external UVC cameras designed for video conferencing.
- Can libcamera handle multiple cameras simultaneously?
- libcamera can support multiple cameras within a system, but allows only a single application to consume the streams from a camera. An application must ‘acquire’ a Camera to start operations on it, and should release it when finished. Logical cameras where multiple cameras are treated as a single camera is a pipeline and hardware specific extension that will be supported in the future.
- Does libcamera do format conversion and debayering?
- Format conversion and debayering operations are dependent upon the Image Signal Processor (ISP) and hardware available. Our demonstration application, QCam, does basic software format conversions to handle display but we aim to move to using OpenGL to improve real time conversion performance. Where possible, QCam will request formats that can be displayed natively without requiring software conversions.