> -----Original Message----- > From: Laurent Pinchart [mailto:laurent.pinchart@xxxxxxxxxxxxxxxx] > Sent: Tuesday, September 27, 2011 11:36 PM > To: Hiremath, Vaibhav > Cc: Ravi, Deepthy; linux-media@xxxxxxxxxxxxxxx; tony@xxxxxxxxxxx; > linux@xxxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > mchehab@xxxxxxxxxxxxx; g.liakhovetski@xxxxxx > Subject: Re: [PATCH 4/8] ispvideo: Add support for G/S/ENUM_STD ioctl > > Hi Vaibhav, > > On Monday 19 September 2011 17:31:02 Hiremath, Vaibhav wrote: > > On Friday, September 16, 2011 6:36 PM Laurent Pinchart wrote: > > > On Friday 16 September 2011 15:00:53 Ravi, Deepthy wrote: > > > > On Thursday, September 08, 2011 10:51 PM Laurent Pinchart wrote: > > > > > On Thursday 08 September 2011 15:35:22 Deepthy Ravi wrote: > > > > >> From: Vaibhav Hiremath <hvaibhav@xxxxxx> > > > > >> > > > > >> In order to support TVP5146 (for that matter any video decoder), > > > > >> it is important to support G/S/ENUM_STD ioctl on /dev/videoX > > > > >> device node. > > > > > > > > > > Why so ? Shouldn't it be queried on the subdev output pad > directly ? > > > > > > > > Because standard v4l2 application for analog devices will call these > > > > std ioctls on the streaming device node. So it's done on /dev/video > to > > > > make the existing apllication work. > > > > > > Existing applications can't work with the OMAP3 ISP (and similar > complex > > > embedded devices) without userspace support anyway, either in the form > of > > > a GStreamer element or a libv4l plugin. I still believe that analog > video > > > standard operations should be added to the subdev pad operations and > > > exposed through subdev device nodes, exactly as done with formats. > > > > I completely agree with your point that, existing application will not > work > > without setting links properly. But I believe the assumption here is, > > media-controller should set the links (along with pad formants) and all > > existing application should work as is. Isn't it? > > The media controller is an API used (among other things) to set the links. > You > still need to call it from userspace. That won't happen magically. The > userspace component that sets up the links and configures the formats, be > it a > GStreamer element, a libv4l plugin, or something else, can as well setup > the > standard on the TVP5146 subdev. > Please look at from analog device point of view which is interfaced to ISP. OMAP3 ISP => TVP5146 (video decoder) As a user I would want to expect the standard to be supported on streaming device node, since all standard streaming applications (for analog devices/interfaces) does this. Setting up the links and format is still something got added with MC framework, and I would consider it as a separate plug-in along with existing applications. Why do I need to write/use two different streaming application one for MC compatible device and another for non-MC? > > The way it is being done currently is, set the format at the pad level > > which is same as analog standard resolution and use existing application > > for streaming... > > At then end of the OMAP3 ISP pipeline video data has long lost its analog > roots. I don't think standards make sense there. > I don't agree with you here, I think we made it clear when we started with MC development activity, we will not break existing standard applications. Media-controller will play a roll to setup the links, connecting the pads and stuff. Thanks, Vaibhav > > I am ok, if we add s/g/enum_std api support at sub-dev level but this > > should also be supported on streaming device node. > > -- > 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
