How to remove pulldown flags from an MPEG2.TS

[edo1080]

Hi,

I want to remove pulldown flags from an MPEG2.TS file. This is a flagged file, since pulldown is not hardcoded in it but only flagged. I'm looking for a TOOL removing flags without re-encoding the file at all. This can be done on flagged pulldown files I know, while if I would have removed pulldown from an hardcoed file, re-encoding would have been the only way. Thanks for you help.

[neuron2]

Use DGPulldown. The help file describes how to remove the pulldown.

http://neuron2.net/dgpulldown/dgpulldown.html

"Note that if the custom rate conversion is selected, and if the source rate is
specified as equal to the destination rate, then all pulldown is removed and the
stream is flagged as having a rate equal to the specified destination rate."

[edo1080]

Thanks for your answer, but is this operation without re-encoding the stream? re-encoding is not required if the stream is simply flagged and not hardcoded.

My source is 29.97 interlaced, MPEG2repair reports 24.28 telecine so if I well unterstood I have to set as both source and destination 24.28 to have the stream with no pulldown and not re-encoed

[neuron2]

DGPulldown does not re-encode.

I'd be dubious about that frame rate. You can't set 24.28 because it is not a legal MPEG2 rate. It's probably 23.976.

[edo1080]

you are right, anyway the file is errorfree, but there's a master error in the telecine, there are some missing frames; I guess this is the cause accelerating the stream; in the point where the frames are missing , the movie seems accelerating for some msecs and there it restores to the normal speed.The following is the m2r log:

File Size Processed: 19.55 GB, Play Time: 01h:51m:43s
1920 x 1080, 29.97 fps (24.28 fps Telecine), 45.00 Mbps (22.95 Mbps Average).
Average Video Quality: 115.42 KB/Frame, 0.46 Bits/Pixel.
MPEG Audio.

My question is : if we assume there are no errors in the stream, setting output at 23.976 could involve the re-encode of the whole stream?

[neuron2]

No. I don't know why you keep asking about that. DGPulldown just clears the RFF flags and sets the frame rate. Your only concern could be AV sync, if there are errors. If there are no errors, then the AV sync will be unaffected, because the video run time is unchanged (as long as you specify the correct frame rate).

To assess the impact for errored streams, run it through DGPulldown, saving to a different file. Then compare the video run times of the before and after streams.

What are you actually trying to do? What is your desired end product?

And I forgot to mention, you'll have to demux your video from the TS file because DGPulldown acts on video ES only.

[edo1080]

What are you actually trying to do? What is your desired end product?
Right answer; all I want is to have the same stream without pulldown and at 23.976 fps and without re-encoding. Since you wrote:

DGPulldown just clears the RFF flags and sets the frame rate

DGPulldown is all I need; I'll try and then report

[edo1080]

I performed some tests, and now I unterstood how DGPulldown is working. It's perfect, but it's my file having an error.