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MP4 container format specification, Trying to write a low memory parser
saratoga
post Jan 10 2009, 22:41
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I've been working on making an mp4 parser for AAC files more memory efficient for targets with very little RAM. Unfortunately, just looking at source code for various parsers its somewhat difficult for me to see how the container actually works.

I've tried google but have found surprisingly little in the way of a detailed specification. Could someone recommend one to me?
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davelasker
post Jan 11 2009, 01:40
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QUOTE (Mike Giacomelli @ Jan 10 2009, 14:41) *
I've tried google but have found surprisingly little in the way of a detailed specification. Could someone recommend one to me?
Does this help? http://developer.apple.com/documentation/Q..._section_1.html

Dave
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saratoga
post Jan 11 2009, 02:43
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QUOTE (davelasker @ Jan 10 2009, 19:40) *
QUOTE (Mike Giacomelli @ Jan 10 2009, 14:41) *

I've tried google but have found surprisingly little in the way of a detailed specification. Could someone recommend one to me?
Does this help? http://developer.apple.com/documentation/Q..._section_1.html

Dave


That looks good, and apparently its very close to how mp4 works.

I'm still not really understanding how one walks through a chunk full of samples though. Is there header or similar on each chunk or sample that tells you about it, or do you have to parse that from the "sample table atom"?
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davelasker
post Jan 11 2009, 03:20
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QUOTE (Mike Giacomelli @ Jan 10 2009, 18:43) *
I'm still not really understanding how one walks through a chunk full of samples though. Is there header or similar on each chunk or sample that tells you about it, or do you have to parse that from the "sample table atom"?
I am the author of aacgain and I had to answer your question to write it. I couldn't find the answer in any publicly available documentation, so I did it by using mpeg4ip/mp4v2 library. There is also some example code in faad2 that you could use.

Hope that helps...

Dave
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