Hi Steven > > The datastream sent keeps the field order of the original footage. When > > constructing the yuv4pmeg2 stream, cinelerra by default appears to assume > > top-field-first which, while perhaps being appropriate for NTSC-land (which > > The capture hardware I use has bottom field first for everything not > just the "DV" family of codecs. > > So the problem could be that the tag is just getting (arbitrarily) > set wrong in Cinelerra.
Could well be. > > I have no direct experience with) is not right for those of us using PAL > > (which is always bottom-first). Thus if one is using bottom-field-first > > Are you 100% certain of this? DV is always bottom field first - that > is true for 625line (PAL)) or 525line NTSC. I have a MJPEG sample > sent to me from a fellow in Austria and that file is top field first > (came from either a DC10 or DC30 - I forget which). No, I'm not certain - I just seem to recall reading somewhere that NTSC-DV did things differently sometimes. It was a while ago though so I might be confusing it with another issue. It is odd that cinelerra's default settings export YUV4MPEG2 with the "top field first" flag set without any reference to the source material though. Oh well, I guess there are some interesting aspects to the program; perhaps it's an effect from earlier development where the input streams *were* top-field first. > (technically PAL and NTSC are color modulation schemes but are > overloaded to mean 625 line and 525 line video systems - it is possible > to, like in Brazil, have a 525 line system with PAL color - it's > PAL/M as I recall) Indeed - "overloaded" is very much the word. Take for instance the DVD standard; a standards-compliant PAL DVD can consist of a single MP2-encoded soundtrack, but if it's an NTSC DVD having a single MP2 audio track is *not* standards compliant. For an NTSC disc you must have either a PCM or AC3 soundtrack. How can the colour modulation method have any bearing on the audio encoding method? Go figure. <shrug> > But as far as I know "PAL" can have either field order - the choice > is made at acquisition time by the hardware being used. I believe that's true. > Thank you for the information and the clarification. I was wondering > if the "heroinewarrior" had suddenly become reachable ;) No problem. Regards jonathan ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
