On Fri, 2008-06-13 at 09:18 +0200, Levente Novák wrote: > I have the following problem with my Hauppauge PVR-150 (ivtv from kernel > 2.6.25) and Composite 1 as input: when a VCR is hooked onto the input > and is switched on (but play is not yet started), instead of a static > blue screen with the usual VCR OSD text, I see a picture which resembles > to a TV station which the frequency is not exactly locked to. In other > words, the blue screen with OSD is there, but there are a multitude of > thin horizontal coloured lines,
What color are the lines? Do they seem to be every other line (i.e. all the lines in either the odd or even field)? > the picture flickers, and is constantly > misaligned horizontally. What does $ v4l2-ctl --log-status show for the card when the blue screen with OSD is displayed? Does it match the video standard your VCR uses? Especially of interest are the cx25840 status lines, since that chip does digitization and has synchronization circuitry, automatic gain controls, chroma subcarrier lock circuitry, etc. > Under Windows with WinTV the image is perfect. > > One more observation: after pressing on the VCR's play button, the image > becomes good and the recordings are OK, so the said problem seems to > affect only the static information screen. What about live tv video demodulated by the VCR and sent to the composite output of the VCR? Have you tried a different compsite video cable? It might matter if the VCR's generated signal for the blue screen and OSD is of marginal quality. I realize the ivtv driver should be able to perform as well as the Windows driver, but a cable replacement is still a simple fix if it resolves your symptoms. > But as this latter has > problems, I am not really sure the recordings are OK indeed or I simply > fail to see the artefacts. What ultimately matters are your perceptions. If you perceive the active playback video looks OK, then you really have no problem. You can ask someone in their teens or early 20's to confirm the video has no artifacts beyond the norm for VCRs. (Perceptions of younger people should be more sensitive to artifacts, but someone that young might not know the "norm" for VCRs due to limited exposure to older technology.) VCR video quality isn't that great. VHS decimates the video to about half the number of lines being actually recorded onto the tape. VHS also restricts video bandwidth somewhat (~3 MHz) which affects horizontal resolution. http://en.wikipedia.org/wiki/VHS -Andy > Levente _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
