Hello, everyone. When it comes to using v4l2 standard spec, I have a question about that.
A month ago, Kamil Debski posted second version for the driver of a hw video codec. To be exact, it is decoding function of hw video codec which is called MFC(Multi Format Codec). For members not accustomed to this, refer to link as below. : http://www.spinics.net/lists/linux-media/msg24682.html I'm preparing for patch of encoding function of MFC. But simply I could say, According to the current version of v4l2 standard, User cannot call encoder or decoder differentially. I mean, Kamil designed MFC decoder driver using m2m style(not using by m2m framework, but V4L2_CAP_VIDEO_OUTPUT, V4L2_CAP_VIDEO_CAPTURE) And it would be almost same to implement encoder in terms of using same m2m style. But user should be able to call decoder for decoding, Due to the same reason, user should be able to call encoder. Of course, some different functions b/w encoder & decoder are called. (Driver should know what function(enc or dec) is called) What do you think is the best way to let driver know what function user wants to execute ? 1. VIDIOC_QUERYCAP is mandatory, but it doesn't define about any encoder, decoder in the v4l2_capability : we need new capability for codec such as V4L2_BUF_TYPE_VIDEO_ENCODER, V4L2_BUF_TYPE_VIDEO_DECODER 2. What about using VIDIOC_S_CTRL, but it requires new defined decoder or encoder as a ctrl.id. Another problem is VIDIOC_S_CTRL is optional 3. What about VIDIOC_S_FMT ? it is also optional, which means default format will be used if not VIDIOC_S_FMT called. Let me know best way such as one among appropriate way that I mentioned as above, or any other idea ? Thanks all ---------------------------------------------------------------------- peter Oh, Senior Engineer SW Solution Development Team, System LSI Division, Samsung Electronics, Co., Ltd. Phone: +82-31-32-52287 Mobile:+82-10-3369-1989 Email: jaeryul...@samsung.com ----------------------------------------------------------------------- -- 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
