iPods, mP3,mP4s

iPod is a brand of portable media players designed and marketed by Apple Inc. and launched on October 23, 2001 (2001-10-23). The product line-up includes the hard drive-based iPod Classic, the touchscreen iPod Touch, the video-capable iPod Nano, and the compact iPod Shuffle. The iPhone can function as an iPod but is generally treated as a separate product. Former iPod models include the iPod Mini and the spin-off iPod Photo (since reintegrated into the main iPod Classic line). iPod Classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued Mini used a Microdrive miniature hard drive). As with many other digital music players, iPods, excluding the iPod Touch, can also serve as external data storage devices. Storage capacity varies by model.
Apple's iTunes software can be used to transfer music to the devices from computers using certain versions of Apple Macintosh and Microsoft Windows operating systems.[2] For users who choose not to use Apple's software or whose computers cannot run iTunes software, several open source alternatives to iTunes are also available.[3] iTunes and its alternatives may also transfer photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars to iPod models supporting those features. Apple focused its development on the iPod line's unique user interface and its ease of use, rather than on technical capability. As of September 2008[update], more than 173 million iPods had been sold worldwide, making it the best-selling digital audio player series in history.[4]

iPod is a brand of portable media players designed and marketed by Apple Inc. and launched on October 23, 2001 (2001-10-23). The product line-up includes the hard drive-based iPod Classic, the touchscreen iPod Touch, the video-capable iPod Nano, and the compact iPod Shuffle. The iPhone can function as an iPod but is generally treated as a separate product. Former iPod models include the iPod Mini and the spin-off iPod Photo (since reintegrated into the main iPod Classic line). iPod Classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued Mini used a Microdrive miniature hard drive). As with many other digital music players, iPods, excluding the iPod Touch, can also serve as external data storage devices. Storage capacity varies by model.
Apple's iTunes software can be used to transfer music to the devices from computers using certain versions of Apple Macintosh and Microsoft Windows operating systems.[2] For users who choose not to use Apple's software or whose computers cannot run iTunes software, several open source alternatives to iTunes are also available.[3] iTunes and its alternatives may also transfer photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars to iPod models supporting those features. Apple focused its development on the iPod line's unique user interface and its ease of use, rather than on technical capability. As of September 2008[update], more than 173 million iPods had been sold worldwide, making it the best-selling digital audio player series in history.[4]

[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.[5] 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.[6] 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[7] 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.[8]