MP4 player: Difference between revisions
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== Operations == |
== Operations == |
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In general, it is simple to operate with some buttons with multiple actions, like play, stop, Enter etc. (in one writer's experience of one player |
In general, it is simple to operate with some buttons with multiple actions, like play, stop, Enter etc. (in one writer's experience of one player, the MENU button usually invokes both menus and navigates into folders, with the PLAY button completing an operation). Some have additional buttons on the side of the player, while others stick to a 'Star' configuration at the bottom of the screen, with a single selection button or Joystick in the center of the Star. |
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== Supported File formats == |
== Supported File formats == |
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Revision as of 21:25, 14 July 2006
Chinese MP4/MTV Player is a flash based Digital audio player, mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play MP4 format videos and are limited to proprietary file formats such as MTV, DMV, MPV and AMV. They are a kind of the S1 MP3 Player.
General features
- Picture viewing:- JPG, BMP and some others depending on model.
- Video: AMV and others depending on model.
- Music: MP3 and others depending on model.
- EBook viewing and Text (normal ascii .TXT format).
- Phone Book facility: format in which they are created depends on the model.
- Built-in Radio
- Voice and Radio record.
- Games. Depending on model.
- Each directory can hold upto 99 items (anything higher depends on model).
- Devices may (and in some cases, must) be charged via the computer's USB port
- Software on Micro disk with drivers for Windows 98 and below
- Battery life of several hours, though differing depending on usage (e.g, playing video gives lower battery life than audio)
Design
Some are tiny (1.2 inch screens) and very light weight without internal speakers. Others are more robust in design (1.5+ inch screens) with additional facilities like built-in speakers and two earphone sockets. Most players feature a 65k OLED display which produce brighter color images than LCD displays, though the image quality is generally quite poor. Normally supplied with micro Stereo Ear phones, USB lead and driver disk (and possibly charger). Some may also be supplied with a special carrying case.
Operations
In general, it is simple to operate with some buttons with multiple actions, like play, stop, Enter etc. (in one writer's experience of one player, the MENU button usually invokes both menus and navigates into folders, with the PLAY button completing an operation). Some have additional buttons on the side of the player, while others stick to a 'Star' configuration at the bottom of the screen, with a single selection button or Joystick in the center of the Star.
Supported File formats
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 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80MBytes in size (in this writer's experience).
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.
Firmware Downloads
Firmware images are available from the following sites:-