pcHDTV :: View topic - HD-3000: How to watch/record normal NTSC video in MythTV?

Niz · Guest

I'm having no luck watching/recording plain old analog NTSC cable in mythTV with my HD-3000. TvTime displays NTSC channels fine with it, so I know the card is working, but with mythTv I get the following messages from the backend:

2004-11-25 02:23:04 Changing from None to WatchingLiveTV
2004-11-25 02:23:04 Maximum signal strength detected: 100% after 0 msec wait
2004-11-25 02:23:19 Couldn't read data from the capture card in 15 seconds. Game over, man.
2004-11-25 02:23:29 Changing from WatchingLiveTV to None

And from the frontend I get:

2004-11-25 02:23:04 Connecting to backend server: 127.0.0.1:6543 (try 1 of 2)
2004-11-25 02:23:04 Using protocol version 8
2004-11-25 02:23:04 Using protocol version 8
2004-11-25 02:23:04 Using protocol version 8
2004-11-25 02:23:09 taking too long to be allowed to read..
2004-11-25 02:23:14 taking too long to be allowed to read..
2004-11-25 02:23:19 taking too long to be allowed to read..
2004-11-25 02:23:21 Waited 2 seconds for data to become available, waiting again...
2004-11-25 02:23:23 Waited 2 seconds for data to become available, waiting again...
and just keeps repeating

Mythtvsetup is set to use PCdtv ATSC capture card on /dev/video0. I've also tried most alternative capture card config combinations such as using /dev/video32 and/or setting it to a Standard V4L capture card instead but that just results in different kinds of errors.

any ideas guys, or is it just not possible for some reason?

Thanks in advance!

Niz.

TedKotz

To do NTSC I've been working with setting it up as a standard V4l tuner and /dev/video0 . I had to modify the code for mythtv in order to get video to work. in mythtv-0.16/libs/libmythtv/NuppelVideoRecorder.cpp I made the following change to line ~1307:
uint8_t *cb_plane = y_plane + w * h;
uint8_t *cr_plane = cr_plane + w * h / 4;
uint8_t *src = buffers[frame];
to:
uint8_t *cb_plane = y_plane + w * h;
uint8_t *cr_plane = cb_plane + w * h / 4;
uint8_t *src = buffers[frame];

This prevented a segmentation fault in the backend.

Now that I have video and it's not seg faulting I'm trying to get audio. Nothing is coming from the tuner card for my sound card to capture.

TedKotz

It seems that mythtv wasn't telling the card to unmute audio in the v4l2 path I submitted the following to mythtv it isn't very clean, but it works.
I'm using a pchdtv HD-3000 card in analog capture mode. I found that the audio
wasn't being unmuted. There seems to be no code for this so I added the
following to NuppelVideoRecorder.cpp StartRecording()(0.16) or Open()(cvs):
if (usingv4l2)
{
/* ADDITION */
struct v4l2_control vc;

memset(&vc, 0, sizeof(vc));

vc.id=V4L2_CID_AUDIO_MUTE;
vc.value=0;

if (ioctl(fd, VIDIOC_S_CTRL, &vc) < 0)
perror("VIDIOC_S_CTRL:V4L2_CID_AUDIO_MUTE");

/* END ADDITION */

if (vcap.card[0] == 'B' && vcap.card[1] == 'T' &&
vcap.card[2] == '8' && vcap.card[4] == '8')
correct_bttv = true;

if (QString("cx8800") == QString((char *)vcap.driver))
{
channelfd = open(videodevice.ascii(), O_RDWR);
if (channelfd < 0)
{
cerr << "Can't open video device: " <<
videodevice << endl;
perror("open video:");
KillChildren();
return;
}

inpixfmt = FMT_NONE;
InitFilters();
DoV4L2();
return;
}

now I'm working on a problem where what looks like vbi data is visible in the image as a set of black and white lines at the top of the picture.

Guest

guest · Guest

What's the status on the pcHDTV drivers? There hasn't been an update in 5 weeks and the 1.6 driver doesn't work with MythTV nor does digital audio capture.

pcHDTV_tech

We have been focusing on getting our drivers in sync with the video4linux drivers. The video4linux driver currently recommends using the DVB API for digital broadcast siganls. Therefore, support for the HD3000 card under the DVB API has just been included in the video4linux CVS snapshots. MythTV has support for the DVB API in curent form so if you have a recent kernel (2.6.10 recommended but 2.6.9 can be coaxed into working) you should consider using the new DVB support.

Also by using the latest video4linux you get all the improvements for audio capture made since our 1.6 driver. It should be much better.

Rusty

CoolerQ

pcHDTV_tech

To give you a not so straight answer: that depends.

video4linux lastest CVS doesn't support kernels older than 2.6.x. In kernels older than 2.6.10 you will need to update to the latest dvb-core files to get the ATSC support. If you are looking for improved NTSC performance the video4linux driver has improved greatly. However. the video4linux driver does not have the V4L2 API interface to the digital stream like our current driver. (V4L will not include anything for Digital reception that doesn't conform with the DVB API). Things are in flux right now, but we hope to have ATSC support into Myth quickly.

Hope this didn't confuse you too much... Wink

Rusty

eagle486

pcHDTV_tech

TedKotz

Guest

I've been playing with this.

I'm able to watch TV in myth (0.1 Cool

using the v4l driver, but the colors are off. Myth complains:
"...Couldn't get the color key color, and we need it..."

With mplayer I use:
mplayer -tv driver=v4l2:input=1:adevice=/dev/dsp:width=640:height=480:device=/dev/video0:brightness=60:contrast=25:hue=99:saturation=55:outfmt=yuy2 -vf pp=lb tv://

this fixes the colors.

Any suggestions?

-Tom

Guest

Uh, make that 0.18 not 0.1 Cool