MP4 player

MP4 Player

Chinese MP4/MTV Player is used to describe a group of Digital audio players or Portable Media Players, most commonly manufactured in China. These players are capable of displaying images, videos, and text files. Although commonly called MP4 players, they have little to do with the MP4/M4A/M4V audio and video files. The earlier players were usually unable to play MPEG4 format videos and were limited to proprietary file formats such as MTV, DMV, MPV and AMV. This is beginning to change however, as more of these players manufactured in recent years have begun supporting MPEG4 format video files. Some of them are a variety of S1 MP3 Player.

History

Most Chinese MP4 player manufacturers claim that the first MP4 player was produced by the French company Archos in 2002. Many manufacturers of Chinese MP3 players at that time saw it as an opportunity and launched advertisement campaigns to promote their own brands of video-capable MP3 players as "MP4 players." They advertised that their MP4 players would be the successor to MP3 players, despite at that time, many of their "MP4 players" were just enhanced MP3 players capable of very limited video playback functions. Only a few were able to play MPEG4 video files stored in ASF format. Even fewer were able to play DivX/Xvid video files stored in AVI format. Later on, as more companies started to sell MP4 players with more advanced video playback capabilities, they started a "true MP4 player vs. false MP4 player" advertisement campaign which had somewhat successfully driven the less advanced video-capable MP3 players back to the MP3 player market, standardizing and stabilizing the Chinese MP4 player market.

Common features

Most players include a viewer for image files, such as JPG and BMP. They also play MP3 and other audio files. Conversion software is usually included on a disc. Videos are usually played in the AMV or MTV format, converted from other common formats using the conversion software. Most players also normally include an ASCII text viewer, so that e-books can be read. Some units include a phone book application, a voice recorder, and an FM radio, making it possible to record FM broadcasts. Finally, some units include video games in the firmware.

Front view of 2GB MP4 Player

Side view of 2GB MP4 Player

Memory

Currently, players are advertised as being produced in capacities of up to 8GB (flash based) and 100GB (micro-hard drive based). If the player is advertised as being 4GB, it is most probable that they may have hacked because the memory chips that are normally manufactured by Samsung are not currently supplied in 4GB sizes and will be 1 to 2GB maximum. But that does not mean that two two GB chips aren't used in one MP4 player will not give you the same 4GB. This type of hacking of the flash chip fools operating systems, such as Windows XP, into displaying the memory as 4GB, however it is impossible to store and retrieve this capacity as the real memory is 2GB or less. Sellers also commonly advertise capacities in gigabits (as opposed to gigabytes.) Deceptive descriptions like this are common on sites such as eBay. However, more recently real 4GB MP4 players are coming out, but it is uncommon and caution should be taken when buying from any seller.

Some of the more recent Chinese MP4 players support third-party expansion flash memory cards, for example, SD/MiniSD/MicroSD, to extend the capacity of the MP4 players.

Battery

The battery can last for several hours, although this amount greatly varies depending on the model of the player and what the player is being used for. For example, the device could be used to play video files which would drain the battery more quickly than playing audio files. New players now have batteries that can last up to 12 hours while older players have a maximum use of 6 hours. In addition to improved battery life, some of the mp4 players now use a cell phone battery which makes it easy to replace the battery should it fail.

Connection

These players have USB 1 or USB 2 support. Older models only support USB 1.1. Some newer models may be able to utilize the full USB 2.0 speed.

Design

These players come in many forms, some are very small with 1.2 inch screens and very light weight. Others are larger and more robust with 1.5 to 2 inch screens with built-in speakers and two earphone sockets instead of one. Most players also feature a 65k OLED display which produce brighter colored image than normal LCD displays, although the image quality generally suffers because of this.

These players are generally supplied with Stereo Ear phones, a proprietary USB cable and a disc with the appropriate drivers. Depending on the model, the package for the players may also include a charger. Some may also be supplied with a special carrying case.

It should also be noted that the outer plastic cover of some players is of low quality and the clear plastic that protects the screen cracks easily. There are many complaints about these issues from users all over the world.

Operations

In general, it is simple to operate the players; a small amount of buttons can perform multiple actions, like play, stop, enter and etc. Some players have additional buttons , while others provide the simpler 'star' configuration adjacent to the screen, with a single selection button or joystick in the center of the star.

Supported File formats

AVI Video Format

The AVI Video Format was created by Microsoft sometime ago and is no longer their official format. However, it is supported by all Microsoft players. The Rockchip mp4 chipset from China conveniently supports this format where divx compression is used. An avi converter that creates divx avi files in the size of the screen supported by the device is needed to create videos for that device.

MTV Video Format

The MTV Video format was created to allow video playback capabilities on inexpensive mp3 players without increasing the cost of those players. The format operates by displaying a series of raw image frames while playing MP3 audio.

The MTV format consists of a 512 byte file header, followed by alternating image and audio frames. While the audio frames are encoded with MPEG1 Audio Layer 3 (aka MP3), the image information is stored in uncompressed raw format, according to the player's display hardware specification.

During decoding of the video stream, the audio frames are passed to the mp3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

AMV Video Format

When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (AMV video format). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte for MPEG2/DVD). With a resolution of 128 × 96, and a frame rate of 12 fps, a 30 minute file will be around 80MBytes in size.

ATV Video Format

The ATV Video format was also created to allow video playback capabilities on inexpensive mp3 players without increasing the cost of those players.

ACT Audio Format

Some MP4 players have the ability to record relatively low-quality sound through an inbuilt microphone, or directly from their FM receiver. This sound is generally recorded in WAV or ACT format.

SMV Video Format

The SMV Video format was also created and used primarily on sigmatel chip-based mp4 players.

Utilities

Various utilities are available that will allow screen graphic displayed characters to be redesigned and uploaded to the player. These are simple to use and generally require BMP format pictures in their respective screen sizes, giving the full benefits of colour and clarity. Menu screens can be redesigned.

Firmware updates

Many of the players are sold with a standard user manual and the section on firmware updates states "go to the website for firmware updates", often with no website given, while if a website is given, it may not have the correct updates for a particular player. An incorrect firmware update is difficult or impossible to undo, and will likely involve dismantling the device and shorting the memory to put it into 'recovery mode'. It is generally considered a bad idea to attempt a firmware upgrade as the benefit is likely negligible and one risks ruining the player software.

Chipsets

Rockchip

A plethora of mp3/mp4 players coming from China starting in 2006 utilize the video processing system-on-a-chip 'Rockchip'. These are often quoted in shipped specifications as requiring the mtv file format for video display. They sometimes even arrive with software that creates *.mtv's. However, these rockchip players actually use *.avi's processed with DIVX mp4 compression. A software which uses divx encoding and creates the proper size is reported to suffice. However, a program referred to as 'AVIConverter' will create the proper size and compression avi.

Critisisms

MP4 players seem to be the only ones that do not support any DRM scheme which means that they can only play unprotected files.

TODO: This section

External links

• MP4 Player tools - support and downloads
• MP4 Player Search - Community powered and driven
• MP4 Nation Knowledge Base: Support and tips on MP4 Players
• Video Review of iPod Nano Clone on YouTube
• Video Review of iPod Video type player - Plays xVid video files
• Recovering dead players and other software
• MP4 Forums on S1MP3.org