关于uvc 的问题，enum_frame_formats获取的格式在PC和嵌入式上不同

pengroo

有一个CAMERA
在嵌入式平台：ARM9，2416 内核：linux3.1
PC 机： 虚拟机Fedora 10  内核：linux2.6.27，
采用luvcview -L 支持的格式相差很大，不光制式有区别，支持的像素也有很大区别，
我现在要设置1024X576，不成功

ARM 下：
Device information:
  Device path:  /dev/video0
/dev/video0 does not support read i/o
{ pixelformat = 'YUYV', description = 'YUV 4:2:2 (YUYV)' }
{ discrete: width = 320, height = 240 }
        Time interval between frame: 1/5,
{ discrete: width = 160, height = 120 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
PC 下：
/dev/video0 does not support read i/o
{ pixelformat = 'YUYV', description = 'YUV 4:2:2 (YUYV)' }
{ discrete: width = 1024, height = 576 }
        Time interval between frame: 1/15, 1/10, 1/5,
{ discrete: width = 864, height = 480 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 640, height = 480 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 640, height = 360 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 544, height = 288 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 432, height = 240 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 352, height = 288 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 320, height = 240 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 320, height = 176 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 176, height = 144 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 160, height = 120 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 752, height = 416 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 800, height = 448 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 800, height = 600 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 960, height = 544 }
        Time interval between frame: 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 960, height = 720 }
        Time interval between frame: 1/15, 1/10, 1/5,
{ discrete: width = 1184, height = 656 }
        Time interval between frame: 1/10, 1/5,
{ discrete: width = 1280, height = 720 }
        Time interval between frame: 1/10, 1/5,
{ pixelformat = 'MJPG', description = 'MJPEG' }
{ discrete: width = 864, height = 480 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 640, height = 480 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 640, height = 360 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 544, height = 288 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 432, height = 240 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 352, height = 288 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 320, height = 240 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 320, height = 176 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 176, height = 144 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 160, height = 120 }
        Time interval between frame: 1/60, 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 752, height = 416 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 800, height = 448 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 800, height = 600 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 960, height = 544 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 960, height = 720 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 1024, height = 576 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 1184, height = 656 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,
{ discrete: width = 1280, height = 720 }
        Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5,


为什么在ARM平台下，不支持640x480呢？我在网上也搜索很多资料，没有结果。
可能原因：
（1） ARM平台采用的usb1.1， PC下是USB2.0，我也问过摄像头的厂家，他们在USB1.1上没有问题，可以设置像素大小
ARM 下的USB 有USB HUB， 可能对USB的传输速度还是有影响。
（2）ARM 下frame buffer的限制，屏幕不支持，可我这里没有GUI 界面，枚举格式支持跟屏有关？
（3）内存不足，可我查看了内核的驱动，没查询到哪里有buffer的限制

有人能告诉我 是内核裁剪的问题，还是其他原因吗，搞了好多天了，谢谢！

pengroo

自己顶一下

pengroo

自己结贴了，经过测试，这个真跟USB1.1 有关，同样的代码，换成USB2.0 就没此类问题