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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Linux Media Mailing List <linux-media@vger.kernel.org>,
	Ezequiel Garcia <ezequiel@collabora.com>
Subject: Re: [RFC] V4L2_PIX_FMT_MJPEG vs V4L2_PIX_FMT_JPEG
Date: Mon, 01 Oct 2018 15:03:04 +0300	[thread overview]
Message-ID: <1670593.gmhJL1mYtv@avalon> (raw)
In-Reply-To: <71200c21-1073-789c-aa94-813042afc352@xs4all.nl>

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

  reply	other threads:[~2018-10-01 18:40 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-01  8:43 [RFC] V4L2_PIX_FMT_MJPEG vs V4L2_PIX_FMT_JPEG Hans Verkuil
2018-10-01 11:48 ` Laurent Pinchart
2018-10-01 11:54   ` Hans Verkuil
2018-10-01 12:03     ` Laurent Pinchart [this message]
2018-10-01 16:31       ` Ezequiel Garcia
2018-10-01 17:19         ` Dave Stevenson
2018-10-05 11:55           ` Mauro Carvalho Chehab
2018-10-05 12:58             ` Hans de Goede
2018-10-01 12:42 ` Nicolas Dufresne
2018-10-01 13:33   ` Laurent Pinchart
2018-10-01 16:12   ` Ezequiel Garcia
2018-10-01 16:28     ` Hans Verkuil
2018-10-01 17:09       ` Laurent Pinchart
2018-10-05 11:52   ` Mauro Carvalho Chehab

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