Stuttering DVD on fast movement

[akkers]

I had HD 16:9 footage (top field first) which I edited and then converted to mpeg2 (top field first) at around 4500 rate. I put this file through tmpgenc DVD authoring and it recognised and set the top field first.

When I play the resulting DVD on a player/TV, the picture looks ok, panning shots are ok. However, whenever there is fast movement the pic stutters or judders. For example, a person sitting still on a chair moves his hands, the picture stays fairly stable but the hands start to stutter.

I would have thought if field order was wrong then the whole pic would stutter including the panning shots. In any case footage was top field and I have kept it that way all the way through.

[jagabo]

Post before and after samples. Use a program mpg2cut or dgindex to extract the samples without re-encoding.

[Brad]

Using American rates here, but the same would apply to 25Hz/50Hz.

Possibly the pans were shot at 1/30 shutter while the interview-type footage was 1/60. "Wrong" field order during the 1/30 shots won't stutter, because both fields would be from the same moment in time.

[akkers]

Original footage was HD 1980x1080 PAL 50i frameserved to mpeg encoder.

I did another encode and this time swapped the field flag and it made no difference.

[davexnet]

Please post some short sample showing movement, as was suggested earlier.

[akkers]

What I found was that if I encode the mpeg2 file using the very very best setting (very slow) then there is less of this stutter, though not totally eliminated.
So I suspect that the stuttering was a result of not enough passes and poor motion detection.
Will have to look for an alternative mpeg2 encoder.

[poisondeathray]

What I found was that if I encode the mpeg2 file using the very very best setting (very slow) then there is less of this stutter, though not totally eliminated.
So I suspect that the stuttering was a result of not enough passes and poor motion detection.
Will have to look for an alternative mpeg2 encoder.

Unlikely.

A more common culprit would be non-frame accurate frameserving

How are you frameserving, provide some more details

[jagabo]

1080i converted to 576i properly will not lose any motion smoothness, even at low bitrates. You've obviously done something wrong but nobody can give you concreted advice until you've provided a sample of your source -- since it appears to be somewhat unusual. And posting a sample of your converted video will give clues to what you did wrong.

[akkers]

I would have posted a sample but the footage contains people who would not consent to me posting it to public.
But encoding again using the best performance (more passes) has reduced the problem. So I would say it was the encoding process that was at fault.

[poisondeathray]

Unlikely that it was the encoding process. Very unlikely.

At least provide the details of how you are frameserving. A far more common culprit is serving frames out of order e.g. your decoder is probably messing up AVCHD source decoding (I'm assuming that's what your source was)