MP4 files (MPEG-4 Part 14) are multimedia files. MP4 is a container format that can store video, audio and subtitle data (as well as more depending on content). Since stores like iTunes uses this container format, and it is used with iPod and PlayStation Portable (PSP), MP4 files have become more common.
MPEG-4 Part 14 or MP4, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital video and digital audio streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. A separate hint track is used to include streaming information in the file. The only official filename extension for MPEG-4 Part 14 files is .mp4.
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The .ogg file format is a type of audio file that makes use of open source Ogg Vorbis compression. It is supported by devices such as Archos and Samsung but is not supported by Apple iOS devices. The .ogg format has been utilised for the provision of streaming audio. The file format is unlikely at present to take a dominant share of the digital music market due to the synonymous nature of MP3 with digital audio.
The .ogg format is actually a container that potentially allows for different streams of audio, video and metadata. Ogg Vorbis is the compression format. It provides medium to high quality audio at between 16 and 128 kbps/channel and is better quality sound than mp3. The OGG file type is a lossy codec which means that data is discarded as part of the compression technique, resulting in a smaller file size. Ogg files are optimised for music files, but will still be of acceptable quality for speech only files.
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