Hello, Mem2mem devices currently use V4L2_CAP_VIDEO_CAPTURE and V4L2_CAP_VIDEO_OUTPUT capabilities. One might expect that a capture device is a camera and an output device can display images. If I remember correct our discussion during the Helsinki v4l2 summit, Hans de Goede has pointed that such devices are listed in applications and can confuse users. The user expects a camera and he has to choose from a long list of devices.
The solution to this would be the introduction of two new capability V4L2_CAP_VIDEO_M2M. Such devices would not be listed when user is expected to choose which webcam or TV tuner device to use. Another thing about m2m devices is the naming of buffers: V4L2_BUF_TYPE_VIDEO_CAPTURE means the destination buffer and V4L2_BUF_TYPE_VIDEO_OUTPUT means source. This indeed is confusing, so I think the introduction of two new buffer types is justified. I would recommend V4L2_BUF_TYPE_M2M_SOURCE and V4L2_BUF_TYPE_M2M_DESTINATION to clearly state what is the buffer's purpose. I would be grateful for your comments to this RFC. Best wishes, -- Kamil Debski Linux Platform Group Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
