Bufferless (on the fly) video data generation for the video device class #3322
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added 2 commits
October 30, 2025 12:21
…me data on the fly - If buffer is set to NULL, the callback will request payload data from a user function. This allows to work with dynamic content on platforms which are not able to hold a whole frame in memory. - Callback uses the same "weak" linking as other callbacks for this class.
…d with e.g. nanoCH32V305 board with the following settings: - tusb_config.h - #define CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE 1024 - #define CFG_TUD_VIDEO_STREAMING_BULK 1 - #define CFG_EXAMPLE_VIDEO_DISABLE_MJPEG - #define CFG_EXAMPLE_VIDEO_BUFFERLESS and - usb_descriptor.h - #define FRAME_RATE 60
![codescene-delta-analysis[bot]](https://avatars.githubusercontent.com/in/53921?s=60&v=4){kind=small}
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…tructure in order to meet coding guideliness
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Thank you, tested on STM32U5, please fix pre-commit whitespace issue as I can't push to your branch (got permission denied). |
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Sorry for the whitespaces, should have looked a bit deeper into the logs. Did some experiments with a new Editor and didn't had my settings right. |
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On smaller devices, there isn’t enough RAM to store an entire high-resolution frame. I haven’t found a way to use the video device without such a buffer, so I added a callback mechanism that allows the code to request payload data on the fly. This makes it possible to generate or forward data without storing a whole frame at once.