Frequently Asked Questions

Q: Where can I find RVC-CAL applications?
A: RVC-CAL applications used to be part of Orcc, now they are available in a separate project called "Open RVC-CAL Applications" initiated by EPFL, Akatech, and IETR. This project contains several applications, such as a JPEG codec, video decoders (MPEG-4 part 2, MPEG-4 AVC, AVS, HEVC), smart motion estimation, cryptographic algorithms, and even an embryo of a GZIP parser.

Q: How do I reference another project?
A: Right-click on the project, Build Path > Configure Build Path... Go to the "Projects" tab, and add the project you want to reference. Please do not use the "Project references" associated with a project's properties.

Q: Where do I subscribe to the mailing lists?
A: We have two mailing lists about Orcc. The first one is for discussions, suggestions, and questions concerning the use of the tool: orcc-list. We also have a mailing list concerning the development of Orcc, which is where technical discussions related to development take place, and to which you can subscribe here: orcc-devel.

Q: Why does the API keep changing?
A: The API is constantly being updated to track the needs of users and researchers working with Orcc. One of the goal of the tool is to provide a platform for research about dynamic dataflow programs, and as such it is generally not possible to anticipate what researchers will need in a future version. As per agile software development, we write software in an incremental manner, adding new features when we have demands or the opportunity, changing the API if necessary, rather than spending time designing a product that will need to evolve before it is finished anyway.

Q: What does PermGenSpace mean?
A: Java has two pools of memory, one is for the objects created by the application, and the other one is for constants (e.g. Strings) and classes. While the well-known OutOfMemoryError is caused by the first heap being too small for the needs of the application, the PermGenSpace error is encountered when the second pool is too small for the needs of the application. Due to the large number of classes and constants that Eclipse uses, it must run with a PermGenSize of 512MB rather than the default size (something like 32MB). When running Orcc in a new Eclipse Application, the maximum PermGenSize is not necessarily set, in which case you must set it to 512 MB explicitly, for that see Run Orcc

Q: Can I use Orcc as a standalone application, outside Eclipse IDE?
A: No. For the moment Orcc has some dependencies against Eclipse SDK. It cannot be used as standalone application, but it is possible to use it in a command line environment (even without X server). To do so, check ci-server-scripts repository, and the corresponding documentation.

Q: Why Orcc is an Eclipse plugin? I don't like Eclipse, why didn't you develop Orcc as part of [type your prefered editor here]?
A: Orcc has been built on top of Xtext SDK for CAL language features. It provides a nice parser, linker, text editor and ease the code generation. Graphiti SDK is also used, providing a high level diagram editor to build beautiful networks quickly. These 2 frameworks are part of Eclipse SDK, that's why Orcc is a set of Eclipse plugins. If you want to use the code generation part of Orcc in a command line environment, there is a workaround. Please see the previous question.

Q: How can I compile an application generated using the C backend with debugging symbols?
A: You have to set the CMAKE_BUILD_TYPE variable to Debug when you generate the CMake project (using -DCMAKE_BUILD_TYPE=Debug in command line)

Q: Why my HEVC application seems to stay stuck and doesn't display anything?
A: Don't forget to increase the size of your FIFOs (Run config > Compilation options). A value of at least 8192 is needed.

Q: Why is a frequently asked question not answered here?
A: Well, as you can see this FAQ is still very much incomplete! Please send us a mail (see question above) and we'll add your question to this list.


Quick install

Install Orcc from the update site
More information


Whether you need (or want to offer) help or advice, or if you just want to discuss/chat about Orcc, feel free to contact us!

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