mpeg-4 : What is it?
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mpeg-4 : What is it?
If I purchase a track from i-tunes it comes in the mpeg-4 format. Is this similar to an mp3 in quality? I plan on converting it to a wav file, but want to make sure I'm not converting a compressed file.
Anyone know what an mpeg-4 is? I know it's originally meant for motion picture use.
-KF
Anyone know what an mpeg-4 is? I know it's originally meant for motion picture use.
-KF
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Re: mpeg-4 : What is it?
MP3's can have all kinds of bitrates ranging from very very little upto 320kbps...King Frydai wrote:If I purchase a track from i-tunes it comes in the mpeg-4 format. Is this similar to an mp3 in quality? I plan on converting it to a wav file, but want to make sure I'm not converting a compressed file.
Anyone know what an mpeg-4 is? I know it's originally meant for motion picture use.
-KF
I personally wouldnt buy tracks off iTunes for using with Live, check out http://www.allofmp3.com/
they seem to be better priced than iTunes and have more bitrate options available.
unfortunatly Mpeg4 is about as descriptive as "vehicle", great for the coders and standards groups to have a set of standards, but for users and customers it is a nightmare.
You can basically implement any part of MPEG4 and it is then mpeg4 compliant, but that might mean you just made a video, some audio, compressed lossless, or lossy, etc.
just dig this groovy and completely transparent list
You can basically implement any part of MPEG4 and it is then mpeg4 compliant, but that might mean you just made a video, some audio, compressed lossless, or lossy, etc.
just dig this groovy and completely transparent list
MPEG-4 consists of several standards—termed "parts"—including the following:
* Part 1 (ISO/IEC 14496-1): Systems: Describes synchronization and multiplexing of video and audio.
* Part 2 (ISO/IEC 14496-2): Visual: A compression codec for visual data (video, still textures, synthetic images, etc.). One of the many "profiles" in Part 2 is the Advanced Simple Profile (ASP).
* Part 3 (ISO/IEC 14496-3): Audio: A set of compression codecs for perceptual coding of audio signals, including some variations of Advanced Audio Coding (AAC) as well as other audio/speech coding tools.
* Part 4 (ISO/IEC 14496-4): Conformance: Describes procedures for testing conformance to other parts of the standard.
* Part 5 (ISO/IEC 14496-5): Reference Software: Provides software for demonstrating and clarifying the other parts of the standard.
* Part 6 (ISO/IEC 14496-6): Delivery Multimedia Integration Framework (DMIF).
* Part 7 (ISO/IEC 14496-7): Optimized Reference Software: Provides examples of how to make improved implementations (e.g., in relation to Part 5).
* Part 8 (ISO/IEC 14496-8 ): Carriage on IP networks: Specifies a method to carry MPEG-4 content on IP networks.
* Part 9 (ISO/IEC 14496-9): Reference Hardware: Provides hardware designs for demonstrating how to implement the other parts of the standard.
* Part 10 (ISO/IEC 14496-10): Advanced Video Coding: A codec for video signals which is also called AVC and is technically identical to the ITU-T H.264 standard.
* Part 11 (ISO/IEC 14496-11): Scene description and Application engine, also called BIFS, can be used for 3D content or subtitles.
* Part 12 (ISO/IEC 14496-12): ISO Base Media File Format: A file format for storing media content.
* Part 13 (ISO/IEC 14496-13): Intellectual Property Management and Protection (IPMP) Extensions.
* Part 14 (ISO/IEC 14496-14): MPEG-4 File Format: The designated container file format for MPEG-4 content, which is based on Part 12.
* Part 15 (ISO/IEC 14496-15): AVC File Format: For storage of Part 10 video based on Part 12.
* Part 16 (ISO/IEC 14496-16): Animation Framework eXtension (AFX).
* Part 17 (ISO/IEC 14496-17): Timed Text subtitle format.
* Part 18 (ISO/IEC 14496-18 ): Font Compression and Streaming (for OpenType fonts).
* Part 19 (ISO/IEC 14496-19): Synthesized Texture Stream.
* Part 20 (ISO/IEC 14496-20): Lightweight Scene Representation (LASeR) (not yet finished - reached "FCD" stage in January 2005).
* Part 21 (ISO/IEC 14496-21): MPEG-J Graphical Framework eXtension (GFX) (not yet finished - at "FCD" stage in July 2005, FDIS January 2006).
* Part 22 (ISO/IEC 14496-22): Open Font Format Specification (OFFS) based on OpenType (not yet finished - reached "CD" stage in July 2005)
Profiles are also defined within the individual "parts", so an implementation of a part is ordinarily not an implementation of an entire part.
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iTunes actually gives you .m4p files, which are Apple protected files. they are however, a protected version of a .m4a file. .m4a is apple lossless. apple lossless is not a less compressed version of .mp3, it is like a .zip or (more accurately) a .flac. lossless means that no audio data is lost... there is no loss of quality.
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