With the risk of being obvious. (I assume this is an analogue card and that

your input is analogue PAL B/G.)



First of all ; I'm pretty sure that problem will not be solved by changing

any of the ioctl() parameters 

for the MPEG/MP2 encoding.  



1. The looks on the video seems to indicate poor  reception. Is the card

tuned to the right frequency (and is the frequency one of the official

channels?) You could for example use "scantv" (in v4l2-tools) to search for

active channels. How do you adjust the frequency ? Via MythTV or directly

via "ivtv-tune" (or by you own program)



2. Are all your identified channels equally bad ?



3. Is there any chance of plugging in an ordinary TV on the same cable and

if so, does this give a "perfect" picture?



4. Are the channels identified by your "real" TV the same channels you are

using? 



5. Have you captured the videos by simple doing a cat /dev/video0 >

mymovie.mpg ? (or whatever device you system is using)



6. Have you simply tried another coax cable?



Some answers to the questions above might help to pinpoint your issues, and

I might be able to give some more assistance.



/Johan



(I recently spent some time writing some PVR SW using ivtv so so I'm fairly

up to speed on the interfaces - and I'm pretty convinced your results are

due to either poor reception or bad HW)



On Wed, 2 Dec 2009 12:56:08 +0100, Bloke DownThePub

<[email protected]> wrote:

> (Apologies if you've heard this before ... I accidentally sent it to

> mythtv-users, I guess some people are on both.  Ooops!)

> 

> I've set it to tha appropriate standard for Belgium - PAL-B/B1/G - but

the

> quality's quite poor.

> 

> Here are a few short samples.

> 

> http://www.youtube.com/watch?v=GBuLCKgn8f8

> 

> http://www.youtube.com/watch?v=DgvcxxiR96E

> 

> http://www.youtube.com/watch?v=B7Kq3WpMogM

> 

> The upload process seems accurate, the clips look pretty much the same as

> when I look at them in mplayer or download them to a pc and use media

> player

> classic.

> 

> I've noticed the image degrades even worse if I split the output between

> the

> PVR and a TV, but before I run out and buy a signal booster, could it be

> something else?  Of course I'm a lucky guy, it could be both...

> 

> There are numerous settings in v4l2-ctl that I don't really understand:

> 

> v4l2-ctl -d 1 -l

> 

> User Controls

> 

>                      brightness (int)  : min=0 max=255 step=1 default=128

> value=128 flags=slider

>                        contrast (int)  : min=0 max=127 step=1 default=64

> value=64 flags=slider

>                      saturation (int)  : min=0 max=127 step=1 default=64

> value=64 flags=slider

>                             hue (int)  : min=-128 max=127 step=1

default=0

> value=0 flags=slider

>                          volume (int)  : min=0 max=65535 step=655

> default=60928 value=60928 flags=slider

>                         balance (int)  : min=0 max=65535 step=655

> default=32768 value=32768 flags=slider

>                            bass (int)  : min=0 max=65535 step=655

> default=32768 value=32768 flags=slider

>                          treble (int)  : min=0 max=65535 step=655

> default=32768 value=32768 flags=slider

>                            mute (bool) : default=0 value=0

> 

> MPEG Encoder Controls

> 

>                     stream_type (menu) : min=0 max=5 default=0 value=0

> flags=update

>               stream_vbi_format (menu) : min=0 max=1 default=0 value=0

>        audio_sampling_frequency (menu) : min=0 max=2 default=1 value=1

>                  audio_encoding (menu) : min=1 max=1 default=1 value=1

> flags=update

>          audio_layer_ii_bitrate (menu) : min=9 max=13 default=10 value=10

>               audio_stereo_mode (menu) : min=0 max=3 default=0 value=0

> flags=update

>     audio_stereo_mode_extension (menu) : min=0 max=3 default=0 value=0

> flags=inactive

>                  audio_emphasis (menu) : min=0 max=2 default=0 value=0

>                       audio_crc (menu) : min=0 max=1 default=0 value=0

>                      audio_mute (bool) : default=0 value=0

>                  video_encoding (menu) : min=0 max=1 default=1 value=1

> flags=readonly

>                    video_aspect (menu) : min=0 max=3 default=1 value=1

>                  video_b_frames (int)  : min=0 max=33 step=1 default=2

> value=2 flags=update

>                  video_gop_size (int)  : min=1 max=34 step=1 default=12

> value=12

>               video_gop_closure (bool) : default=1 value=1

>              video_bitrate_mode (menu) : min=0 max=1 default=0 value=0

> flags=update

>                   video_bitrate (int)  : min=0 max=27000000 step=1

> default=6000000 value=6000000

>              video_peak_bitrate (int)  : min=0 max=27000000 step=1

> default=8000000 value=8000000

>       video_temporal_decimation (int)  : min=0 max=255 step=1 default=0

> value=0

>                      video_mute (bool) : default=0 value=0

>                  video_mute_yuv (int)  : min=0 max=16777215 step=1

> default=32896 value=32896

>             spatial_filter_mode (menu) : min=0 max=1 default=0 value=0

> flags=update

>                  spatial_filter (int)  : min=0 max=15 step=1 default=0

> value=0 flags=slider

>        spatial_luma_filter_type (menu) : min=0 max=4 default=1 value=1

>      spatial_chroma_filter_type (menu) : min=0 max=1 default=1 value=1

>            temporal_filter_mode (menu) : min=0 max=1 default=0 value=0

> flags=update

>                 temporal_filter (int)  : min=0 max=31 step=1 default=8

> value=8 flags=slider

>              median_filter_type (menu) : min=0 max=4 default=0 value=0

> flags=update

>      median_luma_filter_minimum (int)  : min=0 max=255 step=1 default=0

> value=0 flags=inactive slider

>      median_luma_filter_maximum (int)  : min=0 max=255 step=1 default=255

> value=255 flags=inactive slider

>    median_chroma_filter_minimum (int)  : min=0 max=255 step=1 default=0

> value=0 flags=inactive slider

>    median_chroma_filter_maximum (int)  : min=0 max=255 step=1 default=255

> value=255 flags=inactive slider

>       insert_navigation_packets (bool) : default=0 value=0

> 

> Anybody have ideas for what I should adjust?  Is there anywhere an

> explanation of these terms?

_______________________________________________
ivtv-users mailing list
[email protected]
http://ivtvdriver.org/mailman/listinfo/ivtv-users

Reply via email to