Black Haired Girl With A Navel Piercing, Sunglasses And Portable Media Player Reveals Her Black Nightgown On The Bed In The Hotel Room

Operation
Digital sampling is used to convert an audio wave to a sequence of binary numbers that can be stored in a digital format, such as MP3. Common features of all MP3 players are a memory storage device, such as flash memory or a miniature hard disk drive, an embedded processor, and an audio codec microchip to convert the compressed file into an analogue sound signal. During playback, audio files are read from storage into a RAM based memory buffer, and then streamed through an audio codec to produce decoded PCM audio. Typically audio formats decode at double to more than 20 times real speed on portable electronic processors, requiring that the codec output be stored for a time until the DAC can play it. In order to save power, portable devices may spend much or nearly all of their time in a low power idle state while waiting for the DAC to deplete the output PCM buffer before briefly powering up to decode additional audio.
Most DAPs are powered by rechargeable batteries, some of which are not user-replaceable. They have a 3.5 mm stereo jack; music can be listened to with earbuds or headphones, or played via an external amplifier and speakers. Some devices also contain internal speakers, through which music can be listened to, although these built-in speakers are typically of very low quality.