Date: Wed, 08 Oct 1997 19:30:59 -0700 From: Amancio Hasty <hasty@rah.star-gate.com> To: Joao Carlos Mendes Luis <jonny@coppe.ufrj.br> Cc: rhh@ct.picker.com (Randall Hopper), multimedia@FreeBSD.ORG Subject: Re: [video] tuner input format issues Message-ID: <199710090230.TAA09015@rah.star-gate.com> In-Reply-To: Your message of "Thu, 09 Oct 1997 00:07:07 -0200." <199710090207.AAA28073@gaia.coppe.ufrj.br>
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>From a driver stand point of view , it needs a mechanism for selecting the video format in case that the auto feature fails to detect the proper video format. I am surprised that I didn't originally provided such API. Amancio >From The Desk Of Joao Carlos Mendes Luis : > #define quoting(Randall Hopper) > // Joao Carlos Mendes Luis: > // |Indeed, after sending them I found some other missing modifications. > // |They are mostly related to X widgets interface, so I think you should > // |already have seen them. > // > // I might have, but you might give me a clue just as a double-check. > > Ok. I'll send you (priately) the patches against my last sources when > I get home again. > > // |// First, I'm assuming that selecting anything but NTSC/M, NTSC/J, or > // |// PAL/M on a non-NTSC tuner isn't really a valid thing to do. Similarl y > // |// for selecting the three above types on, say, a Temic or Philips PAL > // |// tuner. And is anything but SECAM valid on a Philips SECAM tuner? > // > // Yeah, I think it still would be useful. When on the tuner input, it'd be > // good to grey-out the choices not supported by the tuner. These wouldn't b e > // greyed out when the selected input was the RCA jacks since the tuner > // wouldn't be configured then (or at least "shouldn't" I'd think). When > // on the tuner, this would prevent bogus attempts to configure NTSC tuners > // for PAL625 formats, and vice versa. > > I don't know enough about PAL625 formats or Philips tuners to be sure. > But I think that the trick with PAL/M and NTSC just worked because the > tuner is working just as a frequency converter and an audio tuner. > The Phase Alternate Line operation and the Chroma Carrier are being > decoded by the bt848 chip. > > In theory, *if* the bandwidth for PAL625 is the same as NTSC525, *and* > the audio carrier is at the same offset, it would work as a PAL tuner > too. But this is improbable, or it would not be called a NTSC tuner. :) > So let's stop mind melting and get back to serious work... :))))) > > // Also, for tuner or RCA input, it would be nice to get the 640x480x30 and > // 768x576x25 hard-coded values out of the app and pull them from the driver > // per input format. > > How would it know the input's size ? I think that's what IFORM_AUTO is > for. So the right way of doing this would be to set the input to auto > mode, wait for sync, and read some status register to find which mode > has been chosen. I think vic does this, since it gives this warning when > my camera is turned off: > > vic: meteor sees no signal(1)-using ntsc. > > Maybe Amancio is better suited to give you a help on this topic. > > Jonny > > -- > Joao Carlos Mendes Luis jonny@gta.ufrj.br > +55 21 290-4698 jonny@coppe.ufrj.br > Universidade Federal do Rio de Janeiro UFRJ/COPPE/CISI > PGP fingerprint: 29 C0 50 B9 B6 3E 58 F2 83 5F E3 26 BF 0F EA 67
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