Hi, In two nodes case, application cannot know the feature via VIDIOC_QUERYCAP. Because decoder and encoder return the same CAPABILITY. OUTPUT and CAPTURE So application should call VIDIOC_G_FMT to recognize the feature. BRs, > -----Original Message----- > From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- > owner@xxxxxxxxxxxxxxx] On Behalf Of Jonghun Han > Sent: Monday, November 29, 2010 8:49 PM > To: 'Laurent Pinchart'; 'Hans Verkuil' > Cc: jaeryul.oh@xxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx > Subject: RE: RFC: Problem of using v4l2 spec with codec function > > > Laurent Pinchart wrote: > > > -----Original Message----- > > From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Laurent Pinchart > > Sent: Monday, November 29, 2010 6:20 PM > > To: Hans Verkuil > > Cc: jaeryul.oh@xxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx > > Subject: Re: RFC: Problem of using v4l2 spec with codec function > > > > Hi, > > > <snip> > > > > If so, then I think creating a so-called 'private' control for your > > > hardware would be the best way to go. As an example of private controls > > > search for the V4L2_CID_MPEG_CX2341X_BASE define in videodev2.h. > > > > I would rely on formats. If the input format is YUV and the output format is > > MPEG, it's pretty obvious that the hardware should be encoding. If the formats > > are the other way around, then the hardware should be decoding. > > Right. But.. > If VIDIOC_S_CTRL is called before VIDIOC_S_FMT, how to distinguish them ? > In my opinion decoder and encoder can have own control Ids. > For example, > After VIDIOC_S_CTRL related in decoder, if VIDIOC_S_FMT for encoder is called > how to return it ? > VIDIOC_S_CTRL has been succeeded because driver cannot know whether > decoder or encoder. > And then is it right that VIDIOC_S_FMT for encoder is failed due to > VIDIOC_S_CTRL for decoder ? > > Can two nodes(encoder, decoder) be the solution ? > > BRs, > > > -- > > Regards, > > > > Laurent Pinchart > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-media" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html