Laurent, Thanks for the suggestion. I have already decided to do it as a second device as per Hans' response. Murali Karicheri Software Design Engineer Texas Instruments Inc. Germantown, MD 20874 new phone: 301-407-9583 Old Phone : 301-515-3736 (will be deprecated) email: m-karicheri2@xxxxxx >-----Original Message----- >From: Laurent Pinchart [mailto:laurent.pinchart@xxxxxxxxxxxxxxxx] >Sent: Tuesday, September 15, 2009 4:17 AM >To: Karicheri, Muralidharan >Cc: Linux Media Mailing List >Subject: Re: Handling second output from vpfe capture - Any suggestion ? > >Hi Murali, > >sorry for the late reply, I was on holidays. > >On Friday 04 September 2009 15:03:00 Karicheri, Muralidharan wrote: >> Hi, >> >> I am working on to add additional capabilities to vpfe capture driver to >> allow capture two frames simultaneously for each received frame from the >> input video decoder or sensor device. This is done using the IPIPE and >> Resizer hw available in DM355. In our internal release this is done by >> configuring IPIPE to receive from directly from CCDC and then passing it >> to the Resizer. Resizer has two outputs that operates on the same input >> frame. One output is usually used for capturing full resolution frame >and >> the other is limited to output VGA or less resolution frames. Typically >> this will be useful for previewing the video on a smaller LCD screen >using >> the second output while using the full resolution frame for encoding. >> >> Since input frame is same for both these inputs, we had implemented using >a >> bigger capture buffer that can hold both the frames. The second frame is >> captured at the end of the first frame. This allowed us to DQBUF both >> frames simultaneously. But we used proprietary IOCTL to change the >output >> size or format. I think a better alternative is to implement another >Queue >> in the vpfe capture that can take a V4L2_BUF_TYPE_PRIVATE. This will >allow >> me to configure the output format of second output independently for the >> second output. Looking at the v4l2-ioctl.c there is support for this >> buffer type. But this buffer type is not used by any driver and I am not >> sure if this will work or is the right approach to deal with this >problem. >> Any suggestion here? > >I think you should create two video devices, one to stream the full >resolution >video and the other one to stream the downscaled video. This is exactly the >kind of use case that is going to be handled by the new media controller >API. > >-- >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
