From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([213.167.242.64]:46906 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728921AbeJASkR (ORCPT ); Mon, 1 Oct 2018 14:40:17 -0400 From: Laurent Pinchart To: Hans Verkuil Cc: Linux Media Mailing List , Ezequiel Garcia Subject: Re: [RFC] V4L2_PIX_FMT_MJPEG vs V4L2_PIX_FMT_JPEG Date: Mon, 01 Oct 2018 15:03:04 +0300 Message-ID: <1670593.gmhJL1mYtv@avalon> In-Reply-To: <71200c21-1073-789c-aa94-813042afc352@xs4all.nl> References: <03c10b29-6ead-1aa2-334a-c6357004a5ac@xs4all.nl> <2438028.OjeO6a9KTA@avalon> <71200c21-1073-789c-aa94-813042afc352@xs4all.nl> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, On Monday, 1 October 2018 14:54:29 EEST Hans Verkuil wrote: > On 10/01/2018 01:48 PM, Laurent Pinchart wrote: > > On Monday, 1 October 2018 11:43:04 EEST Hans Verkuil wrote: > >> It turns out that we have both JPEG and Motion-JPEG pixel formats > >> defined. > >> > >> Furthermore, some drivers support one, some the other and some both. > >> > >> These pixelformats both mean the same. > > > > Do they ? I thought MJPEG was JPEG using fixed Huffman tables that were > > not included in the JPEG headers. > > I'm not aware of any difference. If there is one, then it is certainly not > documented. What I can tell for sure is that many UVC devices don't include Huffman tables in their JPEG headers. > Ezequiel, since you've been working with this recently, do you know anything > about this? -- Regards, Laurent Pinchart