XMA Multichannel Packet Offset

**marlborox** · Joined: 29 Oct 2008 Posts: 9

i know there's the xmaextract tool by bnw33, but it doesn't interleave the audio file's correctly, thus the separate file's are all of different speed's & tempo's when separating from the fsb's (although i know it's a "buggy beta" so it's not been finalized), does anyone have any information on the packet offset as can't find any info out there & have been looking ever since xmaextract was made as would be great to be able to make this tool, or is anyone else working on one at present?

**mxrmxr** · Joined: 22 Oct 2009 Posts: 6

Yeah same problem here. It would be really great if that could be sorted out.

**bnw33** · Joined: 29 Mar 2008 Posts: 42

Maybe I can help,

What is the packet offset you speak of? Is that the start of the audio (eg: Where the first xma packet is in the fsb4 file)? There is a field (DWORD) in the fsb4header, i think its 0x0A (i'm probably totally wrong, but its in the first 32 bytes). It should tell you the length of the sample headers, so if you add the length of the actual fsb4 header ( usually 32 bits), you will get the offset of where the first packet is.

xmaextract uses this field to find the first packet offset, and then from there, deinterleaving follows the specifications in the xma documentation (this deinterleaving process is not very difficult, take a look at the source for xmaextract, it'll give you some clues).

However, if this field does not exist, of the size of the fsb4 header is larger/smaller than what is in place (or the fsb4 file is invalid), xmaextract will happily deinterleave garbage, giving you no warnings (haha, i haven't added any error checking really).

What files are you trying to deinterleave? Maybe this could help me expand the tool, if I ever find some time to work on it.

**marlborox** · Joined: 29 Oct 2008 Posts: 9

**marlborox** · Joined: 29 Oct 2008 Posts: 9

edited

**ccfman2004** · Joined: 09 Jan 2008 Posts: 152 Location: New York, USA

How do I use xmaextract? I am not familiar with java. I am used to .exe files.
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**marlborox** · Joined: 29 Oct 2008 Posts: 9

install the java files & required then from the dos command

java xmaextract songname.fsb

**Event2020** · Joined: 28 Dec 2010 Posts: 6

Hi

Found this topic and I know its old but.....

Following the instructions in the thread I have now got all of the multi's out of a .fsb as single channel .xma's.

As a test, I put one xma in the ToWav directory.

I open a cmd box, go to the ToWav dir and run the following command line:

towav (filename).xma

towav reads the file but does not output anything.

I then tried

towav (filename).xma (filename).wav

again towav seems to read the file (well it gives no errors) but nothing is outputted and no wav is created?

What am I doing wrong please?

Thanks in advance

**bnw33** · Joined: 29 Mar 2008 Posts: 42

towav and xmaextract are quite picky about the header files associated with xma. Xmaextract does not bother with the xma header, and rather uses the fsb file header to make demuxing decisions. Some fsb->xma files do not have proper towav/xmaextract compliant xma headers.

To remedy this, hcs created some header recreation tools on his site, check it out here:
http://hcs64.com/vgm_ripping.html under xma_parse

Thanks to hcs!

**Event2020** · Joined: 28 Dec 2010 Posts: 6