How can I split a x264 movie into small parts?

[Adsmt]

I want to split a x264 movie into three parts and to re-encode some x264 movies without orignial source.
But I failed to load x264 file by VirtualDubMod and cannot load by AviSynth script.

Is there something that I should install first?

[Revgen]

First of all, is your x264 movie .mkv, .mp4 or .avi?

Second of all, are you sure you don't want to use the original source? Re-encoding can cause further quality loss.

[Caroliano]

Besides what Revgen said, what is your avisynth script and what error it gave?

[Adsmt]

OK, thx for reply.
Re-encode is just for test, and my main purpose is to split the movie. I'd like to encode a movie totally and split it into 3 or 4 parts. I don't want to split it before encoding because I want the moive keeping the same quality of each part.
I think I can use VirtualDubMod to split x264 file just like splitting xvid or divx and direct stream copy.
But if I use VirtualDubMod to load x264 file (mkv), I always get the message "VirtualDub requires a Video for Windows(VFM) compatible codec to decompress video. DirectShow codecs, such as those used by Windows Media Player, are not suitable. Only 'Direct stream copy' is availabe for this video" with many frame error warnings.
But if fact, I can't use direct stream copy because frame error warning would be showed when I save the file.

I've tried to use AVISource() to load .mkv file, but it seemed not to work.

[foxyshadis]

mkvmerge gui ;)

In the global tab, it has a splitting section, you can specify the exact size or time you want to split at.

[Caroliano]

For Matroska you shoud use directshowsource(file). This shoud also resolve the problem with codec.

[bond]

for decoding streams in virtualdub you need a decoder of course:

install ffdshow, open it via the codec list in virtualdub, go to the decoder tab, enable h.264

[Adsmt]

OK, thx.
I've tried mkvmerge gui, but it's not as precise as I expect.
I set to split at 00:03:12:777, but it actually split at 00:03:14.xxxx.
...and what is directshowsource? Should I use another file type instead of mkv to split?

[bond]

OK, thx.
I've tried mkvmerge gui, but it's not as precise as I expect.
I set to split at 00:03:12:777, but it actually split at 00:03:14.xxxx.you can only cut at keyframes

...and what is directshowsource? Should I use another file type instead of mkv to split? no, that proposal was useless for what you want to do

[Adsmt]

OK, I got it. thx.
Cutting at keyframes is enough.

[Zak Kingston]

Just to add: For MP4, you may use mp4box for trimming. Works great for me with x264-video...