MP4 player

The name MP4 player is a marketing term for portable media players that comply with certain standards and formats.[3] The name itself is a misnomer, since most MP4 players are incompatible with the MPEG-4 Part 14 or the .mp4 container format. Instead, the term symbolizes their status as successors of MP3 players. [4] In this sense, in some markets like Brazil, any new function added to a given media player is followed by an increase in the number,[5] despite there being no corresponding MPEG-5 standard (as of 2010, the current standard, still being developed, is MPEG-4).
Contents
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1 Technical information
1.1 Rockchip
1.1.1 Other chipsets
1.2 AMV
1.3 MTV
2 Instruction manuals
3 See also
4 Notes and references
5 External links

[edit] Technical information

Some MP4 players include a FM transmitter.
[edit] Rockchip

Fuzhou Rockchip Electronics's video processing Rockchip has been incorporated into many MP4 players, supporting AVI with no B frames in MPEG-4 Part 2 (not Part 14), while MP2 audio compression is used.[6] The clip must be padded out, if necessary, to fit the resolution of the display. Any slight deviation from the supported format results in a Format Not Supported error message.
[edit] Other chipsets

Some players, like the Onda VX979+, have started to use chipsets from Ingenic, which are capable of supporting RealNetworks's video formats.[7] Also, players with SigmaTel-based technology are compatible with SMV (SigmaTel Video).
[edit] AMV
Another MP4 player from Newsmy, a major PMP manufacturer in China
Main article: AMV video format

The image compression algorithm of this format[8] is inefficient by modern standards (about 4 pixels per byte, compared with over 10 pixels per byte for MPEG-2 / DVD video). There are a fixed range of resolutions (96 × 96 to 208 × 176 pixels) and frame-rates (12 or 16 frame/s) available. A 30-minute video would have a filesize of approximately 100 MB at a 160 × 120 resolution.[9]
[edit] MTV

The MTV video format (no relation to the cable network) consists of a 512-byte file header that operates by displaying a series of raw image frames during MP3 playback.[9] During this process, audio frames are passed to the chipset's decoder, while the memory pointer of the display's hardware is adjusted to the next image within the video stream. This method does not require additional hardware for decoding, though it will lead to a higher amount of memory consumption. For that reason, the storage capacity of an MP4 player is effectively less than that of a player that decompresses files on the fly.
[edit] Instruction manuals

The instruction manuals usually contain the basic information to operate and use the devices, but sometimes lack further detail. They are often translated into pidgin English or mistranslated into Engrish