From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:48727 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753273Ab3IAOb6 (ORCPT ); Sun, 1 Sep 2013 10:31:58 -0400 Message-ID: <5223515F.8030002@iki.fi> Date: Sun, 01 Sep 2013 17:38:23 +0300 From: Sakari Ailus MIME-Version: 1.0 To: Su Jiaquan , Laurent Pinchart CC: Guennadi Liakhovetski , linux-media , jqsu@marvell.com, xzhao10@marvell.com Subject: Re: How to express planar formats with mediabus format code? References: <2205654.JNC8mWJ5su@avalon> <2368703.nsGl321KOP@avalon> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Jiaquan and Laurent, Apologies for my delayed reply. Su Jiaquan wrote: > Hi Sakari, > > On Thu, Aug 22, 2013 at 7:29 PM, Laurent Pinchart > wrote: >> Hi Jiaquan, >> >> On Wednesday 21 August 2013 18:14:50 Su Jiaquan wrote: >>> On Tue, Aug 20, 2013 at 8:53 PM, Laurent Pinchart wrote: >>>> Hi Jiaquan, >>>> >>>> I'm not sure if that's needed here. Vendor-specific formats still need to >>>> be documented, so we could just create a custom YUV format for your case. >>>> Let's start with the beginning, could you describe what gets transmitted >>>> on the bus when that special format is selected ? >>> >>> For YUV420P format, the data format sent from IPC is similar to >>> V4L2_MBUS_FMT_YUYV8_1_5X8, but the content for each line is different: >>> For odd line, it's YYU YYU YYU... For even line, it's YYV YYV YYV... >>> then DMA engine send them to RAM in planar format. >>> >>> For YUV420SP format, the data format sent from IPC is YYUV YYUV >>> YYUV(maybe called V4L2_MBUS_FMT_YYUV8_2X8?), but DMA engine drop UV >>> every other line, then send them to RAM as semi-planar. >> >> V4L2_MBUS_FMT_YYUV8_2X8 looks good to me. >> >>> Well, the first data format is too odd, I don't have a clue how to >>> call it, do you have suggestion? >> >> Maybe V4L2_MBUS_FMT_YU8_YV8_1_5X8 ? I've CC'ed Sakari Ailus, he's often pretty >> creative for these issues. >> >> -- >> Regards, >> >> Laurent Pinchart >> > > Does the format V4L2_MBUS_FMT_YU8_YV8_1_5X8 sounds good to you? Do you > have better idea how we should describe this format? If bus (or DMA) transfers 8 bits at a time, then yes. Otherwise perhaps ...1X12. The documentation should be extended to cover different components on alternating lines; I don't think we've had such cases before. I think just a note telling to do exactly as above should suffice. -- Kind regards, Sakari Ailus sakari.ailus@iki.fi