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'extraction' of ogg files from a packed file
oggExtraction
post Oct 24 2008, 13:35
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I am going to 'extract' some ogg files in an exe file. Several page headers are found but finding the end of a ogg file is a problem. Does somebody have any ideas about determinating the end of the ogg file (or the size of the ogg file) from just considering the page header? Thanks for your help! beer.gif
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Peter Harris
post Oct 31 2008, 14:35
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QUOTE (oggExtraction @ Oct 24 2008, 08:35) *
Does somebody have any ideas about determinating the end of the ogg file (or the size of the ogg file) from just considering the page header?


No.

Ogg Vorbis can be used for live streaming, which means it has to generate the headers before it even knows how long the stream will be. The designers didn't feel it was necessary to add an optional length field, either.

There should be an EndOfStream flag on the last packet. Even if you miss that, each packet has a checksum, so you can just keep reading until the checksums fail...
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bhaskarnallani
post Dec 10 2008, 10:20
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QUOTE (Peter Harris @ Oct 31 2008, 19:05) *
QUOTE (oggExtraction @ Oct 24 2008, 08:35) *

Does somebody have any ideas about determinating the end of the ogg file (or the size of the ogg file) from just considering the page header?


No.

Ogg Vorbis can be used for live streaming, which means it has to generate the headers before it even knows how long the stream will be. The designers didn't feel it was necessary to add an optional length field, either.

There should be an EndOfStream flag on the last packet. Even if you miss that, each packet has a checksum, so you can just keep reading until the checksums fail...

hi
Here i am mentioning an issue of the size of page in the ogg files in the demuxer.
i want to know what is the general page size in .ogg streams.
The ogg standard mentioned that there may be upto 64k the page will be, But in the realtime systems
we can not hold 64kB memory to process a cheksum and then demux the ogg page header.

So i just wnat to know that normally developers can mention about the size of the pages in the steems they
can support.
Normally 4 to 8k bytes.
Otherwise what is the alternative to that.
How all portable players are supporting the 64k size of the ogg page in any file ogg vorbies, ogg flac.

If any body have an idea please help me in this issue.

Regards
Bhaskar
India

This post has been edited by bhaskarnallani: Dec 10 2008, 10:22
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