From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:5904 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753148Ab2HNIMq (ORCPT ); Tue, 14 Aug 2012 04:12:46 -0400 Message-ID: <502A08B7.2090704@redhat.com> Date: Tue, 14 Aug 2012 10:13:43 +0200 From: Hans de Goede MIME-Version: 1.0 To: Sylwester Nawrocki CC: Hans Verkuil , linux-media , workshop-2011@linuxtv.org Subject: Re: [Workshop-2011] RFC: V4L2 API ambiguities References: <201208131427.56961.hverkuil@xs4all.nl> <5028FD7E.1010402@redhat.com> <5029526E.7020605@gmail.com> In-Reply-To: <5029526E.7020605@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi, On 08/13/2012 09:15 PM, Sylwester Nawrocki wrote: >>> And if a driver also supports >>> single-plane formats in addition to >1 plane formats, should >>> V4L2_CAP_VIDEO_CAPTURE be compulsary? >> >> Yes, so that non multi-plane aware apps keep working. > > There is the multi-planar API and there are multi-planar formats. Single- > and multi-planar formats can be handled with the multi-planar API. So if > a driver supports single- and multi-planar formats by means on multi-planar > APIs, there shouldn't be a need for signalling V4L2_CAP_VIDEO_CAPTURE, > which normally indicates single-planar API. The driver may choose to not > support it, in order to handle single-planar formats. Thus, in my opinion > making V4L2_CAP_VIDEO_CAPTURE compulsory wouldn't make sense. Unless the > driver supports both types of ioctls (_mplane and regular versions), we > shouldn't flag V4L2_CAP_VIDEO_CAPTURE. > Ok. Regards, Hans