[Libav-user] How to remux an mp4 file without transcoding?

Yisheng Zhao yz1134 at nyu.edu
Fri Nov 22 20:17:10 CET 2013

Hi, Sir/Madam

How are you doing recently?

I have a question how to remux an mp4 file using libav.
Um, as I was able to read from the mp4 file and got each avpacket, I stored
the data from each avpacket to a circular buffer I created.
The problem is that when I wanted to take advantage of the data stored in
my circular buffer, I must use av_malloc and memcpy to create and copy the
data. If I used the data directly from the circular buffer, it did not work.
As I have saw the source code, I found that av_malloc just did the
_aligned_malloc to malloc the data, and I tried that out, but still did not

Attached is my loop doing remux, it is the todo part I wanna figure out. In
particular, I'm using malloc in FrameInfo class, but I have also tried the
_aligned_malloc(size, 16(/32) );

Thank you so much for the help~
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