Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 8 Mar 2007 14:28:50 -0600
From:      "Rick C. Petty" <rick-freebsd@kiwi-computer.com>
To:        Jim Stapleton <stapleton.41@gmail.com>
Cc:        freebsd-multimedia@freebsd.org
Subject:   Re: any application that can read straight form a tv tuner device?
Message-ID:  <20070308202850.GA53058@keira.kiwi-computer.com>
In-Reply-To: <80f4f2b20703081146q52a7d109k81683b12cda6f191@mail.gmail.com>
References:  <80f4f2b20703081146q52a7d109k81683b12cda6f191@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Mar 08, 2007 at 02:46:42PM -0500, Jim Stapleton wrote:
> i.e.
> 
> $ SomeMpegViewer < /dev/cxm0
> 
> I tried mplayer since it was supposed to be able to handle mpg videos
> from stdin, however it gave me an error saying there was too much data
> per packet (I don't have it with me at the moment, so I can't say
> exactly what it is)

Try:

mplayer -cache 4300 /dev/cxm0

> I found that, if I have enough delay between the two commands,
> $ cat /dev/cxm0 > /tmp/tvfile
> $ noatun /tmp/tvfile

For some reason, I think the way the MPEG encoder multiplexes the audio and
video is problematic.  From analyzing the problem, it seems the audio is
multiplexed a few seconds later in the stream than the video.  Telling
mplayer to cache 4.3MB seems to fix this problem for me.  The timestamps on
the video & audio stream are correct, mplayer just need to "read ahead"
farther to find the correct timestamps.

> does the job I need, but, it has some latency, which can be
> problematic (especially if I were playing a console game), also it
> tends to create a rather large file, unncecessarily.

Yes it does and it is quite annoying.  "Live TV" is not live but delayed.
I'm wondering if this is a problem for Windows users and these cards.  I
was never able to get my card working in Windows, and Linux was almost as
broken.  I suspect there's not much we can do because the encoder's
firmware is downloaded to the card when the cxm driver is probed.  It *may*
be just a matter of tweaking settings, Usleep would have a better idea.

-- Rick C. Petty



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070308202850.GA53058>