The difference is massive and so are the download times. RAW file formats generally require 176,000 bytes per second compared to a lossy format which requires 17,600. M4R supports auditory masking - essentially discarding data with minimal loss of quality. It is a lossy algorithm much like AAC and MP3. It is part of the MPEG-4 standard and is specified in the ISO/IEC standard 14496-3. By using lossy formats it enables even dial up users to download mp3 files at a reasonable speed. M4R is essentially a renamed AAC (M4A) file - it is similar to MP3 but compresses the digital audio files further. The reason lossy formats are used over RAW is that RAW audio files are too large to travel over the internet at any great speed. In other words, that means it removes the information that your ear doesn't notice thereby making the file smaller. Instead, MP3 files use perceptual coding. That means that an MP3 file does not contain 100% of the original audio information. This then enables you to get hundreds of songs on to a CD and it also has opened up a new market over the internet - the download market as download times have been significantly reduced. MP3 gets rid of a lot of the information recorded in a song that our ears are not able to hear and then uses complex algorithms to reduce the file size.
MP3 is a digital music format which allows CD tracks to be reduced to around a tenth of their normal size without a significant loss of quality.
Since stores like iTunes uses this container format, and it is used with iPod and PlayStation Portable (PSP), MP4 files have become more common. To convert without re-encoding audio, choose 'Copy' (not recommended).
To use the most common codec, select 'Auto' (recommended). MP4 is a container format that can store video, audio and subtitle data (as well as more depending on content). MP4 is a container format that can store video, audio and subtitle data (as well as more depending on content). Choose a codec to encode or compress the audio stream. MP4 files (MPEG-4 Part 14) are multimedia files. Then change the audio format MP3 is perfect for ringtones. After that, check the Fade in and Fade out, or Crossfade boxes. MP4 files (MPEG-4 Part 14) are multimedia files. MP3 Music Cutter lets you extract or delete it.