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From: Hans de Goede <j.w.r.degoede@hhs.nl>
To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: linux-media@vger.kernel.org
Subject: Re: libv4l2 library problem
Date: Sun, 15 Feb 2009 10:03:41 +0100	[thread overview]
Message-ID: <4997DA6D.5010006@hhs.nl> (raw)
In-Reply-To: <200902150022.20486.hverkuil@xs4all.nl>

Hans Verkuil wrote:
> Hi Hans,
> 
> On Friday 13 February 2009 13:57:45 Hans Verkuil wrote:
>> Hi Hans,
>>
>> I've developed a converter for the HM12 format (produced by Conexant MPEG
>> encoders as used in the ivtv and cx18 drivers).
>>
>> But libv4l2 has a problem in its implementation of v4l2_read: it assumes
>> that the driver can always do streaming. However, that is not the case
>> for some drivers, including cx18 and ivtv. These drivers only implement
>> read() functionality and no streaming.
>>
>> Can you as a minimum modify libv4l2 so that it will check for this case?
>> The best solution would be that libv4l2 can read HM12 from the driver and
>> convert it on the fly. But currently it tries to convert HM12 by starting
>> to stream, and that produces an error.
>>
>> This bug needs to be fixed first before I can contribute my HM12
>> converter.
> 
> My sincere apologies: I looked at the libv4l2 code again and it was clear 
> that it did in fact test for this case. I retested my own code and 
> everything seems to work as it should. So libv4l2 is fine, and I will 
> prepare a tree tomorrow containing the hm12 support for libv4lconvert.
> 

Ok,

> Sorry about this,

No problem I didn't have time to look in to this yet :)

Regards,

Hans

      reply	other threads:[~2009-02-15  8:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-13 12:57 libv4l2 library problem Hans Verkuil
2009-02-14  8:52 ` Mauro Carvalho Chehab
2009-02-14  9:08   ` Hans Verkuil
2009-02-14 10:32     ` Mauro Carvalho Chehab
2009-02-14 11:06       ` Hans Verkuil
2009-02-14 14:05         ` Andy Walls
2009-02-14 14:11           ` Hans Verkuil
2009-02-14 18:58             ` Mauro Carvalho Chehab
2009-02-14 19:57               ` Hans Verkuil
2009-02-14 20:26             ` Andy Walls
2009-02-14 23:22 ` Hans Verkuil
2009-02-15  9:03   ` Hans de Goede [this message]

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