Hans, > -----Original Message----- > From: Hans Verkuil [mailto:hverk...@xs4all.nl] > Sent: Tuesday, May 05, 2009 5:41 PM > To: Mauro Carvalho Chehab > Cc: Mauro Carvalho Chehab; linux-media@vger.kernel.org; Chaithrika U S > Subject: Re: [PULL] http://www.linuxtv.org/hg/~hverkuil/v4l-dvb-davinci > > Hi Mauro, > > > Hans Verkuil escreveu: > >> On Thursday 23 April 2009 13:35:02 Mauro Carvalho Chehab wrote: > >> > >>> On Sun, 19 Apr 2009 12:46:00 +0200 > >>> Hans Verkuil <hverk...@xs4all.nl> wrote: > >>> > >>> > >>>> Hi Mauro, > >>>> > >>>> Please pull from http://www.linuxtv.org/hg/~hverkuil/v4l-dvb- > davinci > >>>> for the > >>>> following: > >>>> > >>>> - v4l: TI THS7303 video amplifier driver code > >>>> > >>> +static int ths7303_setvalue(struct v4l2_subdev *sd, v4l2_std_id > std) > >>> +{ > >>> + int err = 0; > >>> + u8 val; > >>> + struct i2c_client *client; > >>> + > >>> + client = v4l2_get_subdevdata(sd); > >>> + > >>> + if ((std & V4L2_STD_NTSC) || (std & V4L2_STD_PAL)) { > >>> + val = 0x02; > >>> + v4l2_dbg(1, debug, sd, "setting value for SDTV > >>> format\n"); > >>> + } else { > >>> + val = 0x00; > >>> + v4l2_dbg(1, debug, sd, "disabling all channels\n"); > >>> + } > >>> + > >>> > >>> Hmm... Are you sure that the above check is ok? The standards > you're > >>> allowing > >>> are: PAL/BGDKHI and NTSC (except for NTSC/443). So, standards like > >>> PAL/N, > >>> PAL/N', PAL/60, PAL/M will stay away. > >>> > >>> If what you want is all standards but SECAM, then the correct > syntax > >>> would be something like: > >>> if (std & (V4L2_STD_ALL & ~V4L2_STD_SECAM)) > >>> > >>> > >>>> - Analog Devices ADV7343 video encoder driver > >>>> > >>> +#define SD_STD_NTSC (0x00) > >>> +#define SD_STD_PAL_BDGHI (0x01) > >>> +#define SD_STD_PAL_M (0x02) > >>> +#define SD_STD_PAL_N (0x03) > >>> > >>> Hmm... from the comments at the beginning of the .c file, it seems > that > >>> the > >>> hardware supports all standards but SECAM. The above register > >>> definitions also > >>> specifies PAL/M and PAL/M as supported standards. > >>> > >>> However, by looking at the std_into table: > >>> > >>> +static const struct adv7343_std_info > >>> + adv7343_composite_std_info[] = { > >>> + { > >>> + SD_STD_NTSC, 0x1F, 0x7C, 0xF0, 0x21, V4L2_STD_NTSC, > >>> + }, > >>> + { > >>> + SD_STD_PAL_BDGHI, 0xCB, 0x8A, 0x09, 0x2A, > V4L2_STD_PAL, > >>> + }, > >>> +}; > >>> + > >>> +static const struct adv7343_std_info > >>> + adv7343_component_std_info[] = { > >>> + { > >>> + SD_STD_NTSC, 0x1F, 0x7C, 0xF0, 0x21, V4L2_STD_NTSC, > >>> + }, > >>> + { > >>> + SD_STD_PAL_BDGHI, 0x1F, 0x7C, 0xF0, 0x21, > V4L2_STD_PAL, > >>> + }, > >>> +}; > >>> > >>> Hmm.. on the last table, you are using a FSC = 3,579,545.45 Hz for > both > >>> PAL and > >>> NTSC? This seems wrong to my eyes. > >>> > >>> Also, both tables have several supported standards missed. > >>> > >> > >> Mauro, > >> > >> Are there TVs in Brazil that are unable to handle standard NTSC-M on > the > >> composite or S-Video inputs? > > Yes. There are models that only handles PAL-M. > > > >> There are no encoders in v4l-dvb that do > >> something special for PAL-M. > >> > > Maybe because nobody tested they and reported an issue? Before I > started > > working on this, > > most drivers were broken with PAL/M: saa7113, cx88, ivtv, ... > > To be fair, it is very hard to implement something you cannot test > yourself, and most people can only test PAL/NTSC. > > >> All just check against 525 vs 625 line standards. > >> And I can't imagine that that will cause problems for Brazilian TVs. > >> > > If you don't encode with PAL/M, then some TV sets won't work. Also, > even > > on TV sets that supports multiple standards, sometimes we need to > > disable autodetection of NTSC, because this is broken on some TV > sets. > > I've personally experienced this trouble with two TV sets, including > a > > brand-new LCD1080p TV set I bought this year. On some conditions, if > you > > let auto NTSC/PAL-M enabled, it miss-detects the color carrier, and > > changes to the other standard (missing the colors) for some seconds, > and > > then returns back. So, you have moments with colors and moments > without. > > > > It should also be noticed that there are several devices (TV sets, > DVD > > players, etc) manufactured abroad that people assumes that PAL/M > color > > carrier is equal to NTSC (AFAIK, the same occurs with PAL/Nc). Since > the > > color carriers are somewhat different, this produces a very annoying > > effect: the color image will present a static image as a image with > > colors moving, since there will be a frequency shift between the > > horizontal frequency rate and the pixel sampling rate (that are > derived > > from the color carrier on several decoders), causing color detection > > misleading at the pixels. So, the pixels at the boundary of a shape > have > > their colors oscillating. > > Very interesting. I honestly thought that all TVs everywhere (except > perhaps very old ones) would be able to handle 'standard' PAL or NTSC > on > their Composite and S-Video inputs. > > > > >> I think these drivers should just use V4L2_STD_525_60 and > >> V4L2_STD_625_50, > >> just like saa7127 does. > >> > > I have no device here with saa7127, so I'm not sure how this works > with > > other standards. > > Currently it does only PAL and NTSC. Although it can do SECAM it is > never > actually enabled. > > > But, expecially on encoding, you should be able to > > produce the right standard. I can't see it producing a right standard > if > > you just use V4L2_STD_525_60 and V4L2_STD_625_50 with s-video. At > least > > on one place, you should say to the encoder what should be the color > > carrier frequency and if it will encode with PAL, NTSC or SECAM. > > > > > > By the way, what's the rationale of not allowing the driver to encode > on > > all supported formats? > > Generally, not being able to test all the possible standards. Or not > being > aware of this problem at all :-). I agree that this driver should be > enhanced to support more standards. > > Chaithrika, can you take a look at this based on Mauro's input? > Hans,
I will look into this soon after I am done with my current tasks. Thanks, Chaithrika > Regards, > > Hans > > -- > Hans Verkuil - video4linux developer - sponsored by TANDBERG > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
