I want to modify GDLC MP4 Muxer so that

* it will not send data to other writer but it will just record it
itself to a file data itself...
* It will be not a muxer any more...it will be a writer which have mp4 muxer...

**But firstly i have to figure out, where is the last [muxed] data stay , so that i can write it to a file...**

To get a playable file, i have to write the data where?

**My Attempts:**

*I put debug info and see that it calls **Append** and this method call **Replace** periodically...I write the buffer [ BYTE* pBuffer] which is given to Append method of MuxOutput .I get binary data which has some headers but not playable...So it its wrong place or i do it wrong.....Then i check what calls Append --- FillSpace methos and YUVVideoHandler::WriteDescriptor... But can not able to get usefull info from other methods call Append...

**UPDATE**

Well, i can able to write data to file at `MuxOutput::Replace` method...The problem is that the header info and footer(tables at the end of file) are wrong... The other data [ payload data] is correct... The playable file which is recorded by File writer started with **00 00 00 18**...[hexadecimal] but my recorded data start with **00 00 00 08** [hexadecimal].... when i replace the mp4 header and footer parts with the file generated by the file writer using a hex editor tool, file becomes identical and plays.

**What may be the problem?**