Hans Verkuil <hverk...@xs4all.nl> wrote: >I can work on the proposal this week for that. The only reason the fps >hasn't been added >yet is that I never had the time to do the research on how to represent >the fps reliably >for all CEA/VESA formats. Hmm, pixelclock / total_framesize should >always work, of course. > >We can add a flags field as well (for interlaced vs progressive and >perhaps others such as >normal vs reduced blanking). > >That leaves the problem with GTF/CVT. I'll get back to that tomorrow. I >have ideas, but >I need to discuss it first. > >Regards, > > Hans >-- >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
For fps you could use horizontal_line_freq/lines_per_frame. However, all of the non-integer fps numbers I have seen in this email chain all seem to be multiples of 29.97002997 Hz. So maybe you could just use the closest integer rate with a flag labeled "ntsc_bw_timing_hack" to indicate the fractional rates. :) That 29.97 Hz number comes from the NTSC decision in 1953(!) to change the horizontal line freq to 4.5 MHz/286. Note that (4.5 MHz/286)/525 = 30 * (1000/1001) = 29.97002997 Hz It is interesting to see one of the most ingenious analog hacks in TV history (to achieve color and B&W backward compatabilty while staying in the 10% tolerance of the old B&W receivers) being codified in digital standards over 50 years later. It boggles the mind... Regards, Andy -- 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
