http://moitah.net/http://moitah.net/download/latest/MPEG4Modifier.zip如果仅仅是改packed bitstream的话，这个可以改packed bitstream。
MPEG4 Modifier - Modifies MPEG4-ASP AVIs (aspect ratio, userdata, packed bitstream) without re-encoding.
Download:
v1.4.4 (Binary) |
v1.4.4 (Source) 
Modifies MPEG-4 ASP videos (XviD, DivX) without re-encoding (change aspect ratio, edit userdata, remove or add packed bitstream, and change interlaced field order). It can also show information about the video such as the amount of I/P/S/B-VOPs used, whether or not QPel/GMC were used, etc. The video must be in an AVI container. More information can be found in this thread. There's also a command line version sharing most of the same features.
NOTE: Aspect ratio modification works by changing a flag in the VOL headers, which is ignored by most decoders.
Changes:
1.4.4 (2007-Jan-13):
Fixed a few small issues that prevented DivX subtitles from working.
Added *.divx to the supported extension list in the file dialogs.
A default file name is now provided when saving.
1.4.3 (2006-Nov-05):
Doesn't remove delay frames anymore, this caused synch problems with joined videos.
FourCC and user data information are now shown in the "Video Info" text.
It's now possible to pack videos containing drop frames.
1.4.2 (2006-Sep-16):
Fixed several problems with OpenDML reading/writing (writing bad OpenDML index entries, out of memory exception or unnecessary reading when loading, incomplete loading of files with damaged/missing index).
1.4.1 (2006-Aug-04):
Fixed some problems with packing which also required corrections to the timestamp calculation code.
If you try to load a non-MPEG4 video, the error message now displays which codec the file uses.
Better default directories for load/save file dialogs.
1.4.0 (2006-Aug-03):
AVI handling code completely rewritten, supports OpenDML and incomplete files (rebuilds the index including keyframe flags).
Ability to add/readd packed bitstream.
Optimized some parts, runs significantly faster.
Added Cancel button on load/save progress window.
Doesn't freeze explorer while loading a file after dropping onto the source textbox.
Updated code to take advantage of C# 2.0 features, and lots of cleanup.
Full Change Log
