How to get an mjpeg stream with 30 fps?

Hi, I bought two webcam modules and they are said to be able to deliver 1280x720 with 30 frames per second with mjpg compression. When I now set it up with libuvc_camera node: I always get: > uvc_get_stream_ctrl_format_size:> Invalid mode (-51)> ================================================================================REQUIRED process [cam-2] has died! process has> died ... Also v4l2-ctl tells me it should able to stream that: v4l2-ctl --list-formats-ext -d /dev/video1 ioctl: VIDIOC_ENUM_FMT Index : 0 Type : Video Capture Pixel Format: 'MJPG' (compressed) Name : MJPEG Size: Discrete 1280x720 Interval: Discrete 0.033s (30.000 fps) <-------------- HERE Size: Discrete 640x480 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 1600x1200 Interval: Discrete 0.067s (15.000 fps) Size: Discrete 800x600 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 1920x1080 Interval: Discrete 0.067s (15.000 fps) Index : 1 Type : Video Capture Pixel Format: 'YUYV' Name : YUV 4:2:2 (YUYV) Size: Discrete 1280x720 Interval: Discrete 0.100s (10.000 fps) Size: Discrete 640x480 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 352x288 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 320x240 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 160x120 Interval: Discrete 0.033s (30.000 fps) Size: Discrete 1600x1200 Interval: Discrete 0.200s (5.000 fps) Size: Discrete 1920x1080 Interval: Discrete 0.133s (7.500 fps) Can anybody tell me what I am doing wrong? Lower frequencies sometimes seem to work, For example 10 fps does: But 15 fps for example also do not work. Is there any of those tons of settings here, I have to set to make it work? http://wiki.ros.org/libuvc_camera Camera module is a DELOCK 95953 if that does help. Thanks, Regards, Christian [UPDATE] Meanwhile I found out, how to use it with vlc `vlc v4l2:///dev/video1:width=1280:height=720 :v4l2-chroma=MJPG :v4l2-fps=30` So the framerate and the encoding do acutally work with that camera. Sometimes it hangs for some seconds...