Mailing List Archive: New Mythtv user with Matrox Marvel G200TV

New Mythtv user with Matrox Marvel G200TV

Oct 26, 2002, 5:31 PM

Post #1 of 8 (2580 views)

First and formost I want to say thanks to Isaac and everyone else who has
contributed to this project. I'm really impressed with Mythtv. My system
is as follows:

Dual Celerons @ 500
256MB Ram
2 - 60GB 7200RPM Hard drives, 1 on a ATA33 controller and 1 on ATA66
Matrox Marvel G200TV for video capture and display
Trident 4d Wave PCI sound card using Alsa.
DirecTV Satellite as my primary input/tuner

Some issues I've run into so far:

1. The Marvel captures best used with it's hardware mjpeg compression which
isn't supported in Mythtv (but IS well supported under Linux via the mjpeg
tools). Using raw uncompressed capture the card is limited to around
352x240 with the current Linux drivers.

2. TV Out. this card has 2 methods of outputting video to a TV. The first
method is used by the mjpeg tools and Xawtv. This method is easy to setup
and produces excellent output. The second method requires using the
matrox framebuffer driver and basically involves mirroring your
desktop/console to the TV. It works but it's a pain to get set up just
right and never really looks as good as the first method. Unfortunately
this is the only one supported by Mythtv.

3. For some reason when I watch TV with the record method set to mpeg4 I
see random odd artifacts on the screen. Normally they are a few small
blocks of color. I'm not sure these are real compression artifacts though
since they don't appear if I just record and playback later. Also changing
resolution and quality settings seem to have no affect. I saw some mention
of this in the archives but it was apparently fixed by a newer avifile that
was included in cvs last month and I'm using the current release version.

4. Timed recording isn't real useable since Mythtv doesn't support external
tuners. I know this is in the FAQ but I really didn't understand the
reasoning in the answer. I have a script to change channels on my dss
receiver via serial port so I really just need to get the desired channel #
out to said script. I'll probably ask about this in more detail after I've
looked more carefully at the code. I'm not a real programmer so it may take
a while.

Basically, it looks great and sort of works with my particular hardware but
it would work far better if it could make use of external tools for bits
that actually interface with the hardware. With all of the cheap mjpeg
cards out there and the growing popularity of DV capture and digital cable I
can only see this becoming an issue for more people in the future.

--
Ray

Re: New Mythtv user with Matrox Marvel G200TV [ In reply to ]

seth at yewnix

Oct 26, 2002, 5:42 PM

Post #2 of 8 (2522 views)

Permalink

There is indeed external command functionality in the existing code - it's
just undocumented/unspoken. ;) The code currently only acts as a 'global'
command (eg, it applies to all cards if you have more than 1). I have seen
quite a demand for this in the past week or two, so I think there will end
up being some code contributions to it .... Anyway, last quote from Isaac
regarding the externalcommand functionality is:

>It should be. If you add a line like the following to your settings.txt
file:
>
>str ExternalChannelCommand=changechannel
>
>With 'changechannel' being the program to run on channel change, it'll
execute
>that program like 'changechannel 57' if you tune to channel 57 on a
non-tuner
>input of the capture card. I don't know if anyone's tested it or anything,
>so YMMV.
>
>Isaac

Apparently someone has discovered some issues regarding tuning high channel
numbers with it, however (>125?)... and has throw together a little blurb
about the options to 'fix' it. You may want to hop on
irc.openprojects.net/#mythtv and watch the convo in there, as this is
generally often discussed. =) hopefully your G200TV issues will manifest
into something positive, because it sounds like it could prove to be a nice
myth solution... I too intend to use mythtv w/ my dtv receivers (controlled
via serial port as well).. perhaps we can collaborate on this if you are
interested?

Re,
Seth (skitzo)

----- Original Message -----
From: "Ray" <maillists@sonictech.net>
To: <mythtv-dev@snowman.net>
Sent: Saturday, October 26, 2002 8:31 PM
Subject: [mythtv] New Mythtv user with Matrox Marvel G200TV

> First and formost I want to say thanks to Isaac and everyone else who has
> contributed to this project. I'm really impressed with Mythtv. My system
> is as follows:
>
> Dual Celerons @ 500
> 256MB Ram
> 2 - 60GB 7200RPM Hard drives, 1 on a ATA33 controller and 1 on ATA66
> Matrox Marvel G200TV for video capture and display
> Trident 4d Wave PCI sound card using Alsa.
> DirecTV Satellite as my primary input/tuner
>
> Some issues I've run into so far:
>
> 1. The Marvel captures best used with it's hardware mjpeg compression
which
> isn't supported in Mythtv (but IS well supported under Linux via the mjpeg
> tools). Using raw uncompressed capture the card is limited to around
> 352x240 with the current Linux drivers.
>
> 2. TV Out. this card has 2 methods of outputting video to a TV. The
first
> method is used by the mjpeg tools and Xawtv. This method is easy to setup
> and produces excellent output. The second method requires using the
> matrox framebuffer driver and basically involves mirroring your
> desktop/console to the TV. It works but it's a pain to get set up just
> right and never really looks as good as the first method. Unfortunately
> this is the only one supported by Mythtv.
>
> 3. For some reason when I watch TV with the record method set to mpeg4 I
> see random odd artifacts on the screen. Normally they are a few small
> blocks of color. I'm not sure these are real compression artifacts though
> since they don't appear if I just record and playback later. Also
changing
> resolution and quality settings seem to have no affect. I saw some
mention
> of this in the archives but it was apparently fixed by a newer avifile
that
> was included in cvs last month and I'm using the current release version.
>
> 4. Timed recording isn't real useable since Mythtv doesn't support
external
> tuners. I know this is in the FAQ but I really didn't understand the
> reasoning in the answer. I have a script to change channels on my dss
> receiver via serial port so I really just need to get the desired channel
#
> out to said script. I'll probably ask about this in more detail after
I've
> looked more carefully at the code. I'm not a real programmer so it may
take
> a while.
>
> Basically, it looks great and sort of works with my particular hardware
but
> it would work far better if it could make use of external tools for bits
> that actually interface with the hardware. With all of the cheap mjpeg
> cards out there and the growing popularity of DV capture and digital cable
I
> can only see this becoming an issue for more people in the future.
>
> --
> Ray
>
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev@snowman.net
> http://www.snowman.net/mailman/listinfo/mythtv-dev
>

Re: New Mythtv user with Matrox Marvel G200TV [ In reply to ]

maillists at sonictech

Oct 27, 2002, 10:56 AM

Post #3 of 8 (2508 views)

Permalink

On Sat, Oct 26, 2002 at 08:42:31PM -0400, Seth Wonder wrote:
> There is indeed external command functionality in the existing code - it's
> just undocumented/unspoken. ;) The code currently only acts as a 'global'
> command (eg, it applies to all cards if you have more than 1). I have seen
> quite a demand for this in the past week or two, so I think there will end
> up being some code contributions to it .... Anyway, last quote from Isaac
> regarding the externalcommand functionality is:
>
>
> >It should be. If you add a line like the following to your settings.txt
> file:
> >
> >str ExternalChannelCommand=changechannel
> >
> >With 'changechannel' being the program to run on channel change, it'll
> >execute that program like 'changechannel 57' if you tune to channel 57 on
> >a non-tuner input of the capture card. I don't know if anyone's tested
> >it or anything, so YMMV.
> >
> >Isaac

Thanks, that seems to work mostly. For some reason it only calls my
external command in S-Video & Television mode but not composite, no big
deal for me and probably easy to track down.

>
>
> Apparently someone has discovered some issues regarding tuning high channel
> numbers with it, however (>125?)... and has throw together a little blurb
> about the options to 'fix' it.

Yep, using his modified frequencies.c seems to take care of that. I just
now noticed that Xmltv doesn't seem to be getting my local channel (the
800s) info.

> You may want to hop on
> irc.openprojects.net/#mythtv and watch the convo in there, as this is
> generally often discussed. =) hopefully your G200TV issues will manifest
> into something positive, because it sounds like it could prove to be a nice
> myth solution... I too intend to use mythtv w/ my dtv receivers (controlled
> via serial port as well).. perhaps we can collaborate on this if you are
> interested?

Sure, I'm using a modified version of the script found at
http://www.hitchhiker.org/dss/ to change chanels on my RCA dss receiver.
I'm not a perl hacker but I managed to chop off the interactive bits of that
script and it does manage to change channels and exit as it should.
Mythtv is such a nice piece of software I'm inclined to stick with it and
try to modify the bits that I can to work better with my Marvel. The
capture quality of the Marvel with it's hardware mjpeg really is great and
most fixes for it would apply to other Zoran based capture cards as well
(Iomega Buz, DC10 etc.).

Thanks for your help.

--
Ray

Re: New Mythtv user with Matrox Marvel G200TV [ In reply to ]

tarek at tarek

Oct 27, 2002, 11:18 AM

Post #4 of 8 (2531 views)

Permalink

Note here that Isaac has reported that he just fixed this issue.. I
haven't tried it out, but I shall shortly and report any problems that may
arise.. Needless to say, using a new CVS version is probably better than
using th hacked frequencies.c

tarek : )

> > Apparently someone has discovered some issues regarding tuning high channel
> > numbers with it, however (>125?)... and has throw together a little blurb
> > about the options to 'fix' it.
>
> Yep, using his modified frequencies.c seems to take care of that. I just
> now noticed that Xmltv doesn't seem to be getting my local channel (the
> 800s) info.

Re: New Mythtv user with Matrox Marvel G200TV [ In reply to ]

ijr at po

Oct 27, 2002, 12:21 PM

Post #5 of 8 (2516 views)

Permalink

On Sunday 27 October 2002 12:56 pm, Ray wrote:
> Thanks, that seems to work mostly. For some reason it only calls my
> external command in S-Video & Television mode but not composite, no big
> deal for me and probably easy to track down.

If you could try using current CVS, and see if that works, that'd be cool.

> > Apparently someone has discovered some issues regarding tuning high
> > channel numbers with it, however (>125?)... and has throw together a
> > little blurb about the options to 'fix' it.
>
> Yep, using his modified frequencies.c seems to take care of that. I just
> now noticed that Xmltv doesn't seem to be getting my local channel (the
> 800s) info.

Yeah, as tarek said, this shouldn't be necessary with current CVS anymore.

> Sure, I'm using a modified version of the script found at
> http://www.hitchhiker.org/dss/ to change chanels on my RCA dss receiver.
> I'm not a perl hacker but I managed to chop off the interactive bits of
> that script and it does manage to change channels and exit as it should.
> Mythtv is such a nice piece of software I'm inclined to stick with it and
> try to modify the bits that I can to work better with my Marvel. The
> capture quality of the Marvel with it's hardware mjpeg really is great and
> most fixes for it would apply to other Zoran based capture cards as well
> (Iomega Buz, DC10 etc.).

It really shouldn't be all that difficult to modify things to use the hardware
compression. The API for that is really similar to what's going on with the
current video capture, so at least it _should_ be fairly simple.

Isaac

Re: New Mythtv user with Matrox Marvel G200TV (Resend) [ In reply to ]

maillists at sonictech

Oct 27, 2002, 4:53 PM

Post #6 of 8 (2526 views)

Permalink

I'm re-sending this because the original had the wrong From address, sorry:)

On Sun, Oct 27, 2002 at 03:21:42PM -0400, Isaac Richards wrote:
> On Sunday 27 October 2002 12:56 pm, Ray wrote:
> > Thanks, that seems to work mostly. For some reason it only calls my
> > external command in S-Video & Television mode but not composite, no big
> > deal for me and probably easy to track down.
>
> If you could try using current CVS, and see if that works, that'd be cool.

That fixed it. I can now tune my dss tuner to any channel except the
"local" channels (upper 800s) but that's an XMLTV issue or a problem with
the data source. I did run into 2 new issues however (actually 1 new and 1
old that I had forgotten about).

1. The cvs version exits with the error "Illegal Instruction" if I have
deinterlacing turned on in the settings.txt.

2. mythfilldatabase starts fetching beginning with tommorows data rather
than todays.

>
> > Sure, I'm using a modified version of the script found at
> > http://www.hitchhiker.org/dss/ to change chanels on my RCA dss receiver.
> > I'm not a perl hacker but I managed to chop off the interactive bits of
> > that script and it does manage to change channels and exit as it should.
> > Mythtv is such a nice piece of software I'm inclined to stick with it and
> > try to modify the bits that I can to work better with my Marvel. The
> > capture quality of the Marvel with it's hardware mjpeg really is great and
> > most fixes for it would apply to other Zoran based capture cards as well
> > (Iomega Buz, DC10 etc.).
>
> It really shouldn't be all that difficult to modify things to use the hardware
> compression. The API for that is really similar to what's going on with the
> current video capture, so at least it _should_ be fairly simple.

I'm planning on taking a shot at it but I'm not much of a programmer aside
from the occasional script. I've also mentioned MythTV on the marvel-linux
and mjpeg-user mail lists so maybe someone there will take an interest. One
of the folks on the marvel list has a patched version of ffmpeg that uses the
Marvel's mjpeg hardware so maybe a look at his changes would help.

--
Ray

Re: New Mythtv user with Matrox Marvel G200TV (Resend) [ In reply to ]

ijr at po

Oct 28, 2002, 8:39 AM

Post #7 of 8 (2542 views)

Permalink

On Sunday 27 October 2002 06:53 pm, Ray wrote:
> That fixed it. I can now tune my dss tuner to any channel except the
> "local" channels (upper 800s) but that's an XMLTV issue or a problem with
> the data source. I did run into 2 new issues however (actually 1 new and 1
> old that I had forgotten about).
>
> 1. The cvs version exits with the error "Illegal Instruction" if I have
> deinterlacing turned on in the settings.txt.

Your cpu doesn't do MMX2. You'll need to either disable deinterlacing, or
edit filters/linearblend/filter_linearblend.c and add a #undef MMX at the top
of it.

> 2. mythfilldatabase starts fetching beginning with tommorows data rather
> than todays.

That's normal -- if today's data is empty, it'll do that second. It _always_
grabs tomorrow's data, then fills in any missing days through the week.

> I'm planning on taking a shot at it but I'm not much of a programmer aside
> from the occasional script. I've also mentioned MythTV on the marvel-linux
> and mjpeg-user mail lists so maybe someone there will take an interest.
> One of the folks on the marvel list has a patched version of ffmpeg that
> uses the Marvel's mjpeg hardware so maybe a look at his changes would help.

It'd be easier if someone who had the hardware did the changes.

Isaac

Re: New Mythtv user with Matrox Marvel G200TV (Resend) [ In reply to ]

maillists at sonictech

Oct 28, 2002, 11:05 AM

Post #8 of 8 (2521 views)

Permalink

On Mon, Oct 28, 2002 at 10:39:46AM -0500, Isaac Richards wrote:
> On Sunday 27 October 2002 06:53 pm, Ray wrote:
> > That fixed it. I can now tune my dss tuner to any channel except the
> > "local" channels (upper 800s) but that's an XMLTV issue or a problem with
> > the data source. I did run into 2 new issues however (actually 1 new and 1
> > old that I had forgotten about).
> >
> > 1. The cvs version exits with the error "Illegal Instruction" if I have
> > deinterlacing turned on in the settings.txt.
>
> Your cpu doesn't do MMX2. You'll need to either disable deinterlacing, or
> edit filters/linearblend/filter_linearblend.c and add a #undef MMX at the top
> of it.

Ok, I take it this is something that changed since the last release?

> > I'm planning on taking a shot at it but I'm not much of a programmer aside
> > from the occasional script. I've also mentioned MythTV on the marvel-linux
> > and mjpeg-user mail lists so maybe someone there will take an interest.
> > One of the folks on the marvel list has a patched version of ffmpeg that
> > uses the Marvel's mjpeg hardware so maybe a look at his changes would help.
>
> It'd be easier if someone who had the hardware did the changes.

Agreed, I meant that as "maybe a look at his changes would help ME". That
said, I do have a spare Marvel G200TV complete with breakout box and cables
that you could have if you would be willing to add support for it's hardware
compression and at least try to add support for it's native TV out.

--
Ray