From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.hauppauge.com ([167.206.143.4]:2505 "EHLO mail.hauppauge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755530AbZCaWXL (ORCPT ); Tue, 31 Mar 2009 18:23:11 -0400 Message-ID: <49D297C6.40600@linuxtv.org> Date: Tue, 31 Mar 2009 18:23:02 -0400 From: Michael Krufky MIME-Version: 1.0 To: Dave Johansen CC: Devin Heitmueller , linux-media@vger.kernel.org Subject: Re: Correct signal strength and SNR output for DViCO FusionHDTV7 Dual Express? References: <3731df090903301437k49c310bbha71946ab14c0d6c9@mail.gmail.com> <412bdbff0903301447k6bd27643s7188c17e3ca2798e@mail.gmail.com> <3731df090903310957v119c97e9vbca96d1293d3aef8@mail.gmail.com> <37219a840903311344o56723b21m84e67adcbd1011cd@mail.gmail.com> <3731df090903311516p39ffc59ftfcf161fa158f6dbb@mail.gmail.com> In-Reply-To: <3731df090903311516p39ffc59ftfcf161fa158f6dbb@mail.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: Dave Johansen wrote: > On Tue, Mar 31, 2009 at 1:44 PM, Michael Krufky wrote: > >> On Tue, Mar 31, 2009 at 12:57 PM, Dave Johansen wrote: >> >>> On Mon, Mar 30, 2009 at 2:47 PM, Devin Heitmueller >>> wrote: >>> >>>> On Mon, Mar 30, 2009 at 5:37 PM, Dave Johansen wrote: >>>> >>>>> I am trying to get a MythTV setup working with a DViCO FusionHDTV7 >>>>> Dual Express using Mythbuntu 8.10 and I have been able to generate a >>>>> channels.conf file using the latest v4l-dvb source code and the scan >>>>> utility that comes with the dvb-utils in Mythbuntu (the dvbscan >>>>> utility in latest dvb-apps source code give me the error "Unable to >>>>> query frontend status"). I am also able to watch channels using >>>>> mplayer, but the the problem is that MythTV does not identify any >>>>> channels. I am able to watch channels using MythTV, but I have to >>>>> manually enter the channel data since the tuning is not working. >>>>> >>>>> The belief is that the signal strength and SNR output must be >>>>> incorrect and that is causing the problem with MythTV. I would like to >>>>> help get this fixed, so others don't have the problems that I have run >>>>> into, so what can I do to help get the signal strength and SNR outputs >>>>> working? >>>>> >>>>> If it's helpful, I have attached an example output using azap with one >>>>> of the channels that I can watch with mplayer: >>>>> >>>>> using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0' >>>>> tuning to 503028615 Hz >>>>> video pid 0x0011, audio pid 0x0014 >>>>> status 01 | signal e000 | snr e450 | ber 00000000 | unc 00000000 | >>>>> status 1f | signal 00ff | snr 00ff | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00ff | snr 00ff | ber 00000ab7 | unc 00000ab7 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> status 1f | signal 00fa | snr 00fa | ber 00000000 | unc 00000000 | FE_HAS_LOCK >>>>> >>>>> Thanks, >>>>> Dave >>>>> >>>> Hello Dave, >>>> >>>> There has been an ongoing discussion about the representation of SNR >>>> and strength to applications such as MythTV. Currently it is very >>>> inconsistent across drivers. >>>> >>>> To my knowledge, MythTV does not rely on either of these fields during >>>> its scanning. It relies entirely on the FE_HAS_LOCK to make it's >>>> determination. >>>> >>>> You should probably see what additional logging capabilities are >>>> available in MythTV. >>>> >>>> Also, you might want to see if you can change the lock timeout in your >>>> application, as some applications may have the interval set to a value >>>> too short, which results in it timing out before the lock is acquired. >>>> >>>> Devin >>>> >>>> -- >>>> Devin J. Heitmueller >>>> http://www.devinheitmueller.com >>>> AIM: devinheitmueller >>>> >>>> >>> So, I tried upping the tuning timeout and MythTV under Mythbuntu 8.10 >>> was able to find 1 of the channels (I can find 19 using scan and >>> azap). >>> >>> I then downloaded the Mythbuntu 9.04 beta and got a new antenna. The >>> driver worked out of the box so I didn't need to download/compile the >>> latest v4l-dvb drivers, and it was able to get all 19 channels in >>> MythTV (it took 3 or 4 scans to finally get them all). I realize that >>> that wasn't the most scientific approach, so I will re-try with the >>> old antenna and see if it was the antenna or the software upgrade that >>> did the trick. >>> >>> I also tried cranking the tuning timeout up to 15 seconds and it still >>> couldn't find all of the channels during every scan. Is that something >>> that I need to look into from a MythTV perspective? Or is there >>> something wrong with v4l-dvb that's causing that? >>> >> MythTV's channel scanner is undergoing heavy changes in svn trunk. By >> the time 0.22 comes out, I suspect that MythTV's built-in channel >> scanner will be of a much higher quality. >> >> If you want to get all your channels, I recommend creating your own >> channels.conf using the command line utilities, then import that into >> mythtv via mythtv-setup. >> >> -Mike >> >> > > I have been using scan to generate a channels.conf file and then using > that file when scanning for channels in MythTV, but it only ever finds > a few of the channels when I do a scan in MythTV (even though I can > watch all of them without problems using MythTV). I just repeated the > scan with the imported channels.conf file a few times and it finally > picked up all of the channels. Is that normal/expected behavior? Or > should I just not worry about it until 0.22 comes out? I love MythTV, but I'll be honest -- I have NEVER had a good experience where I could do a single channel scan and end up with all the right channels. I usually have to jump through various hoops, editing channel configurations in mythtv-setup, mythweb, and phpmyadmin. I do not recommend any of that to regular users, and ALWAYS back up your database before messing with your tables. I've been told that the channel scanner in 0.22 is *much* better. I pulled it in from the svn branch a few days ago and I already built it and did a first run test... It looks much better, but I didnt inspect closely yet. If I see any way to improve the channel scanning, I will submit patches to the mythtv folks. However, based on what I've seen so far, I have a feeling that the work Dan's been doing lately will result in much more robust channel scanning for the future. I'd say to just go with what works for now, and when 0.22 comes out, try again. Regards, Mike