image quality question

[labouas]

i encoded a small home movie using ffmpeg,source is dv pal,edit with fcp3.i used the mormal settings mov to svcd (ffmpeg).the result is not so sastisfying,especially on movement then the picture is choppy(squares on details instead of smooth lines),is there a way i can fix this by chamgins some settings in ffmpeg? or another way.any help appreciated.thks

[AntnyMD]

One thing I'd suggest is to increase the bitrate for video to 2520 (if you haven't already). The other th ing I've noticed about playing back MPEG2 video encoded with ffmpegX: it looks like crap, no matter the bitrate, on my computer, especially when I'm doing a preview in DVD Studio Pro. It looks tons better in Quicktime 6, but I don't know why. It always looks better on television, though, so I've stopped judging the "quality" of my encodes by what I see on the computer, but by what I see on TV.

[labouas]

ok,i will try increasing bitrate,i think i already did but i'll try again and maybe try on tv to see if there is any difference.thks

[humdinger]

dvdsp and most movie players/editing software display the video in its native 2 fields 25fps format, whereas qt will take advantage of the fact you are using a monitor and play the video as progressive 50fps, which is why it looks nicer

[looftmac]

There is one other aspect to consider: Interlaced video.

Interlaced video is made up of two half pictures (fields) which are broadcasted at 50Hz (PAL) resp. 59.94 Hz (NTSC). So one frame actually consists of two fields, upper (eneven lines) and lower (even lines).
The sequence of these fields is important, since they capture objects in motion at different times and if they get swapped during the processing you get a "two steps forward and one backward" effect, which looks real choppy. Since computer monitors are always progressive, you probably don't see it there.
Now, here's the deal:
For broadcasting, PAL sends the upper field first, NTSC the lower. To make it even more complicated, the DV-format always puts the lower field first, regardsless of PAL/NTSC.
So there are at least two opportunities to unconsciously swapp the fields:
1. Converting PAL - NTSC
2. Burning PAL video on a SVCD in interlaced mode (since DV uses lower field first, while the TV is expecting upper field first).

Premiere has a function to swap fields and with mediapipe you can force the field sequence through the mpeg2encoder-pipe.

I assume, fcp3 has that ability as well, iMovie unfortunately lacks that function.

BTW, when exporting iMovies into iDVD and burning a DVD, no swapping is neccessary. Apple obviously took care of that internally. That maybe the reason, why encoding with the Apple mpeg2 encoder does not create the choppy videos.

[KillerLoop]

Is it possible to get rid of that problem using ffmpeg? I'm experiencing exactly this problem converting .vob to .m2v with ffmpeg...

Bye!