mp4 editing,...

[Selur]

Does anyone know a tool to split mp4 files (at a specified I frame)?

Haven't tried it, but the only idea I came up till now is:

1st mux the mp4 file into an mkv file (using graphedit)
2nd use VirtualDubMod to split the files (at the I frame)
3rd use Graphedit to remux the mkv files to mp4 files

Cu Selur

[Stux]

Originally posted by Selur
Does anyone know a tool to split mp4 files (at a specified I frame)?

Haven't tried it, but the only idea I came up till now is:

1st mux the mp4 file into an mkv file (using graphedit)
2nd use VirtualDubMod to split the files (at the I frame)
3rd use Graphedit to remux the mkv files to mp4 files

Cu Selur

QuickTime 6

Either you have SP video in which case, select one half, cut, paste into a new movie, then export with pass-through on audio/video to another mp4, repeat with the other half.

OR you have ASP video, in which case you should use the 3ivx Splitter -> 3ivx Muxer to remux to MOV, and then use QT exactly the same as for the SP video case.

[bond]

Originally posted by Stux
OR you have ASP video, in which case you should use the 3ivx Splitter -> 3ivx Muxer to remux to MOV, and then use QT exactly the same as for the SP video case.hm, interesting idea to use quicktime
but why doesnt it handle asp? because of the b-frames?

[Selur]

Does anyone know some other way?
(don't want to buy Quicktime pro ;) )

Cu Selur

[shitowax]

QT6 refuses to open streams it cannot decode (with the exception of b-frames). So, if you use qpel, gmc, mpeg-quant, ... qt6 will not let you open the file, it will cry something like "unsupported MPEG-4 technology" ;)

Originally posted by bond
hm, interesting idea to use quicktime
but why doesnt it handle asp? because of the b-frames?

[bond]

Originally posted by shitowax
qt6 will not let you open the file, it will cry something like "unsupported MPEG-4 technology"crap :sly:
but if 3ivx is installed doesnt it get used to decode in qt and enables the full usage of mpeg-4?

[Atamido]

QT doesn't use DirectShow does it?

[shitowax]

That's the tricky point : QT6 doesn't use DirectShow at all (it uses ... Quicktime ... same impressive but old technology on mac and Windows ;)), so it has got the equivalent of an "mp4 splitter". The problem is that this splitter is very linked to Apple's MPEG-4 decoders, and it doesn't accept to open files that Apples decoders cannot decode... even if, when 3ivx is installed, it could play them ... What is even more stupid is that the Quicktime mov splitter, is NOT linked to Apple's MPEG-4 decoders, so you can perfectly open a mov file containing an ASP MPEG-4 video bitstream and decode it with 3ivx ...

Originally posted by bond
crap :sly:
but if 3ivx is installed doesnt it get used to decode in qt and enables the full usage of mpeg-4?

[bond]

menno once talked about that aheads "nero vision express" will be an editing tool for mp4, but i dont know if thats still the case :(

Originally posted by shitowax
The problem is that this splitter is very linked to Apple's MPEG-4 decoders ... What is even more stupid is that the Quicktime mov splitter, is NOT linked to Apple's MPEG-4 decoderscrap :D
perhaps you 3ivx guys can hack that a little bit to be able to use 3ivx as decoder ;)

EDIT: i now played an ASP MP4 in quicktime and it seems to work! under "file info" it tells me that it is a 3ivx stream...
playback seems to have some problems tough: there are some artifacts here and there visible (i used b-frames and qpel)

[Stux]

It will still edit fine though, and then you can export it back out as an MP4 after editing.

Do try to cut on keyframes (scene changes), because QT supports any where any time frame accurate editing...

Yet, almost all other MP4 players don't (yet).

You should be fine if you're just using QT to split a file in two, its when you start chopping bits of video from one file into another that you'll run into interoperability problems :)