audio - Editing an mp4 by manipulating samples -

i edit/manipulate mp4 file without decoding/encoding frames , know if possible.

assume have 2 sets of audio/video encoded same parameters.

on video side had sequence of frames like: ibppbppbppb , wanted change (where -> inserting) ibppb->ibpp

would work ok?

i want similar aac audio removing/inserting samples.

it possible under circumstances manipulate contents of mp4 file without decoding/encoding frames. instance, can split mp4 file separate files, or concatenate mp4 files. in general, concatenation works if have compatible encoding configurations.

for aac audio streams, there no decoding dependencies between audio frames if streams have same configuration, can editing @ mp4 level without problem.

for video streams, again same configuration, need concatenate streams starting random access points (closed gop).

for these operations, can use mp4box:

mp4box -split 10:20 file.mp4 -out file-split-10-20.mp4 

will create new file containing 10 seconds.

mp4box -cat file1.mp4 -cat file2.mp4 output.mp4 

will concatenate 2 files produce new file.