how to set xfer mode

[fatpunkybearass]

In the example file get start uvc there is this uvc configuration line:
usb->uvcConfiguration(240, 320, FPS2INTERVAL(30), 85 * 1024, _xferBufferA, _xferBufferB, 85 * 1024, _frameBuffer); (parameters set by myself)

How can I set up the xfer mode, i.e. uvc_xfer_bulk or uvc_xfer_isoc? I want to test these modes.

Thank you very much

[lijunru-hub]

You don't need to set the transfer mode; everything is handled automatically.

[fatpunkybearass]

You don't need to set the transfer mode; everything is handled automatically.

I use ESP32S3 with OTG port to receive data from a thermal camera. I basically tested every parameter that I can change, the framerate, width, height are all correct. Just the data_bytes is constantly 1022. And the data displayed on an LCD is also partially correct, but just 10% of the correct full image. I saw somewhere that the data transfer mode (ISOC or BULK ) might be the reason, which means the esp32s3 gets part of the whole frame and neglects the rest. So I just want to give it a test.

Or do you have any idea what could cause the data_byte always be 1022?

Thank you very much!

[fatpunkybearass]

@lijunru-hub hi我估计您大概是乐鑫的开发人员，我直接用中文沟通可以吗？请问你们之后计划继续升级完善这个usb stream库的计划吗？目前我看到很多人都说使用这个库只对于特定的摄像头才有用，所以如果你们目前没有修改xfer mode的方法的话，我可以等你们之后更新升级。

[lijunru-hub]

@fatpunkybearass 应该是摄像头的批量包里给了错误的头，你可以手动的在源码中设置宏 UVC_CHECK_HEADER_EOF 为 false 试一试。这个库只支持 full speed 摄像头，市面上这类摄像头比较少。传输模式不是 esp32 这端决定的。是摄像头本身的行为。这个库的首要维护是在 esp-idf sdk 环境下，目前 arduino 更新维护的频次会低一些。目前这个 usb_stream 两端的代码应该是差不多的。你也可以自行的去 esp-iot-solution 里面拿到源码自行更新。

[fatpunkybearass]

@lijunru-hub hi，谢谢你的回答。我有个问题，我不是很熟悉硬件相关的c语言，尽管我已经学习挺久了。我只熟悉matlab和python（抱歉我是学物理的），我很尽力在尝试找，但是确实找不到你说的这个UVC_CHECK_HEADER_EOF变量在哪个文件。你说的这个变量是在arduino的libraries->esp32_usb_stream里的文件吗（我在arduino ide里安装了esp32_usb_stream的库）。还是说这个变量在c盘的某个esp32的源码文件夹？如果你可以告知位置我不胜感激，我可以自己找相应文件在我电脑里的位置。

目前我只在C:\Users\xx\Documents\Arduino\libraries\ESP32_USB_STREAM\src\original\include里的‘arduino_config.h’里找到了一个‘#define CONFIG_UVC_CHECK_BULK_JPEG_HEADER’的变量，看起来最接近，但不是你说的UVC_CHECK_HEADER_EOF。

[lijunru-hub]

就是这个，把这个宏定义改成 false