On Wed, May 30, 2018 at 01:56:34PM -0700, Steve Longerbeam wrote: > > > On 05/30/2018 11:46 AM, Krzysztof Hałasa wrote: > > Steve Longerbeam <slongerb...@gmail.com> writes: > > > > > > but it should be possible for the user to explicitly request the field > > > > order on CSI output (I can make a patch I guess). > > > If you think that is the correct behavior, I will remove the override > > > code. I suppose it makes sense to allow user to select field order even > > > if that order does not make sense given the input standard. I'm fine > > > either way, Philipp what is your opinion? I'll go with the popular vote :) > > I think it should be up to the user. > > Actually, PAL and NTSC aren't valid names in the digital world. Their > > meaning ends in the ADV7180 (or equivalent). I don't know if PAL and/or > > NTSC specify the field order in the analog frame (meaningful when > > someone hooks a camera with progressive sensor and analog, interlaced > > output), but the digital YUV422 from ADV to CSI isn't NTSC/PAL anymore. > > It's just WxH @ framerate + possible interlacing, sequential fields, > > top-bottom or otherwise, etc. The analog standard names could be used > > here but just as defaults. > > > > If we were strict (and we don't want to force it), then we should set > > NTSC/PAL thing on ADV7180 input, 720x480@29.97i (or 720x576@50i, or > > 704x... etc) on the input parts of the CSI/IPU (where there are no video > > frames yet), and 720x480@29.97i B-T or T-B (or default, or separate > > fields - whatever suits the user) on the output from CSI. > > > > I remember the reversed field order was sometimes needed - for example, > > PAL DV (the casette camcorder thing) produced B-T frames (same as NTSC), > > and to avoid (slight) additional quality loss one had to process it > > (up to e.g. .MP4, DVD, and then to HDMI, SCART etc) as B-T. > > It wasn't a problem in otherwise-PAL-centric environment. > > I tend to agree, I've found conflicting info out there regarding > PAL vs. NTSC field order. And I've never liked having to guess > at input analog standard based on input # lines. I will go ahead > and remove the field order override code.
Note that the code in ipu_csi_init_interface currently hard-codes field order depending on frame size. It could be that selecting opposite field order is as easy as switching the relevant parts of writes to registers CCIR_CODE_2 and _3, but we'd have to pass the desired output field order to this function. I'd welcome if somebody would verify that this works. regards Philipp
