你好。
我想在 3.5" RGB LCD 上显示 usb 摄像头并将其记录到 SD 卡。
一开始我用的是官网现成的荔枝派图片。 然后连接usb camera，但是不识别。 所以我进行了搜索，最后我将设备树中 &usb_otg 的 dr_mode 更改为“主机”。
然后 USB 摄像头被识别但没有驱动程序在那里。 然后我在内核配置中做了一些更改（添加 media_usb_support、V4L2、uvc）并再次编译内核。
现在 uvc 自动识别 usb 摄像头。
我得到 yavta 源代码并交叉编译它并将它添加到 sd 卡。
当我运行 yavta 捕获一些帧时，它返回了一些错误，我无法解决它。
有什么帮助吗？
有满足我要求的现成图像吗？ （显示和记录 usb 摄像头）
请帮我。 我处境艰难。
谢谢
离线
这是输出错误
root@LicheePi:~# ./yavta --capture=25 --file=out.MJPEG /dev/video0
Device /dev/video0 opened.
Device `USB Camera' on `usb-musb-hdrc.1.auto-1' (driver 'uvcvideo') supports video, capture, without mplanes.
Video format: MJPEG (47504a4d) 640x480 (stride 0) field none buffer size 614400
8 buffers requested.
length: 614400 offset: 0 timestamp type/source: mono/SoE
Buffer 0/0 mapped at address 0xb6e10000.
length: 614400 offset: 614400 timestamp type/source: mono/SoE
Buffer 1/0 mapped at address 0xb6d7a000.
length: 614400 offset: 1228800 timestamp type/source: mono/SoE
Buffer 2/0 mapped at address 0xb6ce4000.
length: 614400 offset: 1843200 timestamp type/source: mono/SoE
Buffer 3/0 mapped at address 0xb6c4e000.
length: 614400 offset: 2457600 timestamp type/source: mono/SoE
Buffer 4/0 mapped at address 0xb6bb8000.
length: 614400 offset: 3072000 timestamp type/source: mono/SoE
Buffer 5/0 mapped at address 0xb6b22000.
length: 614400 offset: 3686400 timestamp type/source: mono/SoE
Buffer 6/0 mapped at address 0xb6a8c000.
length: 614400 offset: 4300800 timestamp type/source: mono/SoE
Buffer 7/0 mapped at address 0xb69f6000.
[ 67.288909] uvcvideo: Failed to submit URB 0 (-28).
Unable to start streaming: No space left on device (28).
8 buffers released.
离线
thanks very much
I saw the link berfore.
Exactly there is no reliable solution for that.
I don't know.
How can I enable DMA for UVC?
Thanks
离线
thank you so much.
yes I tried -n and -t and -d flags.
I will see your links and write feedback. thanks again
离线
One more question, have you tried using the -n, -t or -d options in yavta to adjust the number of video buffers, the delay before requeuing buffers and the time per frame?
do you live in China? Can I have any number (whatsapp, wechat, telegram, ...) from you?
thanks
离线