Difference between revisions of "AMV"

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m (External Links: add undiscovered video codecs category)
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==AMV Video File Format==
 
==AMV Video File Format==
AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.
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AMV files are a variant of AVI with the strings "AVI" and "avih" in the header replaced with "AMV" and "amvh". The avi header contains several 'garbage' values as many of the parameters are hardcoded. It contains a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.  
  
There is a open source decoder (written in Perl) for the format at [http://svn.rot13.org/index.cgi/amv]. According to its author [http://blog.rot13.org/2007/08/amv_free_decoder_works.html], the video codec is a modified version of [[Motion JPEG]] and audio is IMA ADPCM. The decoder actually cuts the files into separated [[JPEG]] files and then use the ffmpeg binary to reencode the video in other format.
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There is a open source decoder (written in Perl) for the format at [http://svn.rot13.org/index.cgi/amv]. According to its author [http://blog.rot13.org/2007/08/amv_free_decoder_works.html], the video codec is a modified version of [[Motion JPEG]] but missing quantization tables which are fixed (from jpeg standard) and audio is a variant of IMA ADPCM where the first 8 bytes of each frame are:
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* origin (16bits)
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* index (16bits)
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* audio frame length (32bits).
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The decoder extracts each frame into a [[JPEG]] file and then uses ffmpeg to encode the video in another format.
  
 
==AMV and MTV encoding/transcoding information and utilities==
 
==AMV and MTV encoding/transcoding information and utilities==

Revision as of 19:23, 4 September 2007

  • Extension: amv
  • Samples: [1] and [2]

AMV video origin and history

Little is known about the history of the AMV file format other than it is used by Chinese-made portable MP3 players and has supposedly been created to allow video playback capabilities on inexpensive and low end equipment without increasing the cost of those players with the license royalties and more processor power needed for other more complex format/codec pairs.

AMV Video File Format

AMV files are a variant of AVI with the strings "AVI" and "avih" in the header replaced with "AMV" and "amvh". The avi header contains several 'garbage' values as many of the parameters are hardcoded. It contains a RIFF packed stream of video (video codec?) and MP3 encoded audio.

There is a open source decoder (written in Perl) for the format at [3]. According to its author [4], the video codec is a modified version of Motion JPEG but missing quantization tables which are fixed (from jpeg standard) and audio is a variant of IMA ADPCM where the first 8 bytes of each frame are:

  • origin (16bits)
  • index (16bits)
  • audio frame length (32bits).

The decoder extracts each frame into a JPEG file and then uses ffmpeg to encode the video in another format.

AMV and MTV encoding/transcoding information and utilities

Software players that support AMV and MTV playback

  • Unknown

Hardware players that support AMV and MTV playback

Chinese-made portable MP3 players, also known as S1 MP3 Players.

External Links