I've tried cutting out multiple fragments out of a MKV consisting of AVC1 video and AAC audio but AVI Trimmer always gets stuck during processing. As it seems after the first segment.
When opening the same file with Avidemux, I get a message saying "H.264 detected - If the file is using B-frames as reference it can lead to a crash or stuttering. [...]".
And here is the info provided by mediainfo. I suppose these are really all relevant details I can possibly provide you with...
General
Format : Matroska
Format version : Version 1
File size : 232 MiB
Duration : 21mn 56s
Overall bit rate : 1 478 Kbps
Encoded date : UTC 2007-06-26 19:57:46
Writing application : mkvmerge v2.0.2 ('You're My Flame') built on Feb 21 2007 23:40:55
Writing library : libebml v0.7.7 + libmatroska v0.8.1
Video
ID : 3
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 16 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 21mn 56s
Nominal bit rate : 1 345 Kbps
Width : 704 pixels
Height : 528 pixels
Display aspect ratio : 4:3
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.145
Writing library : x264 core 55 svn-661C
Encoding settings : cabac=1 / ref=16 / deblock=1:-3:0 / analyse=0x3:0x133 / me=umh / subme=7 / brdo=1 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=2 / deadzone=21,11 / chroma_qp_offset=0 / threads=2 / nr=0 / decimate=0 / mbaff=0 / bframes=3 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=3 / wpredb=1 / bime=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=1345 / ratetol=1.0 / rceq='blurCplx^(1-qComp)' / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30
Language : English
Default : Yes
Forced : No
Audio
ID : 5
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 21mn 56s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Title : AAC 128kbps
Default : Yes
Forced : No
Text #1
ID : 1
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : Norsk
Language : Norwegian
Default : Yes
Forced : No
Text #2
ID : 2
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : Dansk
Language : Danish
Default : No
Forced : No
Text #3
ID : 4
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : Engelsk
Language : English
Default : No
Forced : No
Text #4
ID : 6
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : Svensk
Language : Swedish
Default : No
Forced : No