On 29/10/15 20:09, Andy Furniss wrote: > Carl Eugen Hoyos wrote: >> MrNice <wxcvbn2006 <at> iol.ie> writes: >> >>> When I capture some video with the CL ./ffmpeg -debug 1 -f v4l2 -ts >>> mono2abs -channel 1 -video_size 720x576 -pix_fmt yuyv422 >>> -thread_queue_size 512 -i /dev/video0 -c:v ffv1 -level 3 -g 1 >>> -aspect 4:3 -pix_fmt yuv422p /Store3/Test/t_`date >>> +%Y%m%d_%H%M`.mkv -aspect 4:3 -f sdl "Dazzle output" >> >>> from a S-VHS tape and Dazzle DVC100, I was thinking to get an >>> interlaced video file. >> >> Why? I mean: How is FFmpeg (or the FFV1 encoder) supposed to know >> that your v4l input is interlaced? > > Hopefully the device/v4l would pass on this information. > >> (And why shouldn't your S-VHS recording be low-resolution >> progressive?) Maybe I miss something but in this case please >> explain. > > I thought s-vhs was like vhs = one field per stripe on the tape. > > Maybe if what was recorded was progressive you wouldn't care assuming > v4l outputs weaved frames - but a lot of tape contains interlaced so you > would need the field dominance info for that. > > Random thought - as it's analogue field input, I wonder if it's possible > that even with a progressive recorded as interlaced you could end up > with weaved frames that don't "line up". > _______________________________________________
Carl Eugen said on Dec 19, 2012: "To the best of my knowledge, only visual inspection tells you, ..." so, what I did and all the 4 files, (FFV1/h264, with/without -flags +ilme+ildct) are definitely interlaced without any doubt. However tags are not consistent: FFV1 with -flags: interlaced_frame=0, top_field_first=0 FFV1 without -flags: interlaced_frame=0, top_field_first=0 h264 with -flags: interlaced_frame=1, top_field_first=0 h264 without -flags: interlaced_frame=0, top_field_first=0 Questions: - How to get interlaced_frame=1 with FFV1? - Could you confirm top_field_first=0 means bff and really what is in the file? - BTW I have read bff is the usual setting for DV, do you agree I should keep it like that? _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
