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Sun Jan 18 00:47:59 UTC 2009


*******************************************************************************************************************************************************************************************
 dtv_multiplex

You may have noticed that many of your channels are on the same frequency
with different Program ID's (and thus different Video and Audio ID's as
well). This is because each frequency has the ability to carry many
different streams of data, each is given their own id, with a program id for
each channel referencing these video and audio id's. MythTV only needs the
frequency and Program ID to properly tune a channel. The
*dtv_multiplex*table is how MythTV keeps track of the frequencies for
channels.

You can try using mythtv-setup's channel scan to try and find channels. Many
find this won't work properly though. If things work well it should find
all, or nearly all the channels you have in your custom channels.conf file.
This will also have the added benefit of populating your dtv_multiplex
table. If it doesn't work it may populate with non-existant channels and
non-useful frequencies.

The final option is to import your custom channels.conf file. This won't
work 100% properly and you will still have to edit the *channels* table, but
it should give you a proper *dtv_multiplex* table.

It is suggested to modify or verify the table manually using
[phpMyAdmin<http://www.phpmyadmin.net/>],
a web based MySQL management tool. The table has 5 fields which we will find
important,

   - *mplexid* is the individual id number for the frequency entry. Ideally
   they will be in numerical sequence, ie 1,2,3,4,5. If you 'Delete all capture
   cards' when you start, the id's will be in frequency order.
   - *sourceid* is the source for which the entry corresponds to, if your
   digital zap2it lineup is the second source you create in mythtv set, then
   this would be sourceid = 2. (Note that you can create your digital tuner in
   the Capture Card section first and its cardid will be '1', but it will be
   associated with sourceid =2.)
   - *frequency* is the frequency. Each frequency needs only be in the table
   once per source. So if you have 3 channels on the same frequency, it only
   needs to be in *dtv_multiplex* once for that source.
   - *sistandard* should be atsc, its default is dvb, so make sure its
   correct. Use 'update channel set sistandard = "atsc" where sourceid = 2;' to
   set this for all channels in sourceid 2.
   - *modulation* should be qam_256, for North American cable systems.

Now that *dtv_multiplex* is ready, print or write down what frequencies
correspond to what mplexid, we will need these for the *channel* table.
 channels

Now we can modify the channels table. Since we've already populated the
table with the channel information for the guide, all we need to do is
adjust the entries so that MythTV knows how to tune the channel. This only
involves changing two fields, mplexid and serviceid.

In mysql use:

update channel set mplexid='x', serviceid='y' where channum='123';

To see what you are doing, try:

select chanid, channum, callsign, mplexid, serviceid from channel where
sourceid='2';

(presuming that your HD3000 is sourceid 2). This will list the details for
the 29 or whatever number of usable channels you receive.

You may be asking, "What about chanid, channum and freqid?". Well, none of
these really matter when it comes to tuning the channel. *chanid* is the
unique number MythTV gave that channel, it should be the sourceid followed
by the channel number. *freqid* should be the same as *channum* which should
be the channel your cable company assigned.

Now what you will need to do is use the information in your custom
channels.conf file to enter the appropriate mplexid for the frequency of the
channel from dtv_multiplex into mplexid. The other field, serviceid, is the
programid number, the last number in the channel information line of
channels.conf.
*******************************************************************************************************************************************************************************************

Is this still good for doing this manually? It seems like there shold be a
better way to get this into the DB than to have to do it manually...

Thanks,

--00221532cc9c1b8e47046334e759
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

Geoff,<br><br>I was actually trying to scan Cable. When I scanned 8VSB whic=
h I&#39;m assuming is OTA it was the only thing that showed any signs of li=
fe - I made the mistake to &quot;assume&quot; that it was interchangeable w=
ith cable, wrong on my behalf!!<br>
<br>I was successful last night in scanning cable (QAM) and have a channels=
.conf but no way to import it into Myth strangely enough... so my dilemma i=
s how to import the channels.conf. I thought I could get sneaky and import =
it through my other DVB satellite card input and then change the cardid in =
the DB to point to the HD300 but it just locked up mythtv-setup, so I guess=
 I have to manually set up the DB instead???<br>
<br>It looks like this:<br><br><pre><b>KNTV-HD&nbsp;:207000000:QAM_256:65:6=
8:4<br>NBC Wea&nbsp;:207000000:QAM_256:81:84:5<br>KBWB-HD&nbsp;:503000000:Q=
AM_256:49:52:3</b><br></pre><br>It&#39;s kind of strange that there isn&#39=
;t a place to actually import a channels.conf for this card or I just don&#=
39;t know where it is. According to the wiki it should be located with the =
channel scan features in mythtv-setup, but it isn&#39;t, there&#39;s no sca=
n type option allowed for importing a channels.conf file...<br>
<br>From the wiki:<br><br>*************************************************=
***************************************************************************=
***************************************************************<br><h4>
 <span class=3D"mw-headline"> dtv_multiplex </span></h4>
<p>You may have noticed that many of your channels are on the same
frequency with different Program ID&#39;s (and thus different Video and
Audio ID&#39;s as well). This is because each frequency has the ability to
carry many different streams of data, each is given their own id, with
a program id for each channel referencing these video and audio id&#39;s.
MythTV only needs the frequency and Program ID to properly tune a
channel. The <b>dtv_multiplex</b> table is how MythTV keeps track of the fr=
equencies for channels.
</p><p>You can try using mythtv-setup&#39;s channel scan to try and find
channels. Many find this won&#39;t work properly though. If things work
well it should find all, or nearly all the channels you have in your
custom channels.conf file. This will also have the added benefit of
populating your dtv_multiplex table. If it doesn&#39;t work it may populate
with non-existant channels and non-useful frequencies.
</p><p>The final option is to import your custom channels.conf file. This w=
on&#39;t work 100% properly and you will still have to edit the <b>channels=
</b> table, but it should give you a proper <b>dtv_multiplex</b> table.
</p><p>It is suggested to modify or verify the table manually using [<a hre=
f=3D"http://www.phpmyadmin.net/" class=3D"external text" title=3D"http://ww=
w.phpmyadmin.net/" rel=3D"nofollow">phpMyAdmin</a>], a web based MySQL mana=
gement tool. The table has 5 fields which we will find important,
</p>
<ul><li><b>mplexid</b> is the individual id number for the frequency
entry. Ideally they will be in numerical sequence, ie 1,2,3,4,5. If you
&#39;Delete all capture cards&#39; when you start, the id&#39;s will be in
frequency order.
</li><li><b>sourceid</b> is the source for which the entry corresponds
to, if your digital zap2it lineup is the second source you create in
mythtv set, then this would be sourceid =3D 2. (Note that you can create
your digital tuner in the Capture Card section first and its cardid
will be &#39;1&#39;, but it will be associated with sourceid =3D2.)
</li><li><b>frequency</b> is the frequency. Each frequency needs only
be in the table once per source. So if you have 3 channels on the same
frequency, it only needs to be in <b>dtv_multiplex</b> once for that source=
.
</li><li><b>sistandard</b> should be atsc, its default is dvb, so make
sure its correct. Use &#39;update channel set sistandard =3D &quot;atsc&quo=
t; where
sourceid =3D 2;&#39; to set this for all channels in sourceid 2.
</li><li><b>modulation</b> should be qam_256, for North American cable syst=
ems.=20
</li></ul>
<p>Now that <b>dtv_multiplex</b> is ready, print or write down what frequen=
cies correspond to what mplexid, we will need these for the <b>channel</b> =
table.
</p>
<a name=3D"channels"></a><h4> <span class=3D"mw-headline"> channels </span>=
</h4>
<p>Now we can modify the channels table. Since we&#39;ve already populated
the table with the channel information for the guide, all we need to do
is adjust the entries so that MythTV knows how to tune the channel.
This only involves changing two fields, mplexid and serviceid.
</p><p>In mysql use:
</p><p>update channel set mplexid=3D&#39;x&#39;, serviceid=3D&#39;y&#39; wh=
ere channum=3D&#39;123&#39;;
</p><p>To see what you are doing, try:
</p><p>select chanid, channum, callsign, mplexid, serviceid from channel wh=
ere sourceid=3D&#39;2&#39;;
</p><p>(presuming that your HD3000 is sourceid 2). This will list the
details for the 29 or whatever number of usable channels you receive.
</p><p>You may be asking, &quot;What about chanid, channum and freqid?&quot=
;.
Well, none of these really matter when it comes to tuning the channel. <b>c=
hanid</b> is the unique number MythTV gave that channel, it should be the s=
ourceid followed by the channel number. <b>freqid</b> should be the same as=
 <b>channum</b> which should be the channel your cable company assigned.
</p><p>Now what you will need to do is use the information in your
custom channels.conf file to enter the appropriate mplexid for the
frequency of the channel from dtv_multiplex into mplexid. The other
field, serviceid, is the programid number, the last number in the
channel information line of channels.conf.
</p>***********************************************************************=
***************************************************************************=
*****************************************<br><br>Is this still good for doi=
ng this manually? It seems like there shold be a better way to get this int=
o the DB than to have to do it manually...<br>
<br>Thanks,<br><br><br><br><br><br>

--00221532cc9c1b8e47046334e759--


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