Detecting codec in a stream - Hydrogenaudio Forums

Detecting codec in a stream, aac adts vs mp3

stigc View Member Profile	Oct 7 2012, 12:46 Post #1
Group: Members Posts: 142 Joined: 13-December 04 Member No.: 18660	How does e.g. VLC detects the codec when opening a http stream? Both AAC and MP3 has a very short sync mark which often appears in other streams. http://www.flickr.com/photos/52807817@N00/4423485655/ http://www.mp3-tech.org/programmer/frame_header.html This post has been edited by stigc: Oct 7 2012, 12:53

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benski View Member Profile	Oct 7 2012, 18:38 Post #2
Winamp Developer Group: Developer Posts: 662 Joined: 17-July 05 From: Ashburn, VA Member No.: 23375	The first four bytes of an ADTS AAC frame header look exactly like an MPEG-1/2 "Layer 4" frame. So it's quite easy to detect the difference.

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stigc Detecting codec in a stream Oct 7 2012, 12:46

stigc I guess VLC parses the frame length number and see... Oct 7 2012, 13:07

benski The first four bytes of an ADTS AAC frame header l... Oct 7 2012, 18:38

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