AMV

• 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 IMA_ADPCM 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

• open source decoder
• AMV encoding tips
• www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)

External Links

• "Chinese-made portable MP3 player" article on wikipedia.org
• "S1 MP3 Player" article on wikipedia.org
• www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads
• MTV Video topic-thread on moviecodec.com forum
• MP4 Player Search - Community powered and driven
• MP4 Nation Knowledge Base: Support and tips on MP4 Players
• An introduction to MP4 players, what they do, what you can do to them and a review
• Recovering dead players and other software
• MP4 Forums on S1MP3.org
• MTV Video Forum
• (A very negative) video-review of one of these MP4-Player on Youtube
• Chinavasion - China direct wholesaler of MP4 Players using AMV video format