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Defined by MPEG communication protocol. An elementary stream contains only one kind of data, for example audio or video. The output of a video encoder is an elementary stream. The output of an audio encoder is also an elementary stream. Sometimes referred to as "elementary", "data", "audio", or "video" bitstreams or streams. The Moving Picture Experts Group or MPEG is a working group of ISO/IEC charged with the development of video and audio encoding standards. ...
A bitstream or bit stream is a time series of bits. ...
General layout of MPEG-1 audio stream
The digitized sound signal is divided up into blocks of 384 samples in Layer I and 1152 samples in Layers II and III. The sound sample block is encoded within an audio frame: MPEG-1 Audio Layer II (MP2, sometimes Musicam) is an audio codec. ...
MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. ...
- header
- error check
- audio data
- ancillary data
The header of a frame contains general information such as the MPEG Layer, the sampling frequency, the number of channels, whether the frame is CRC protected, whether the sound is the original[1]: The sampling frequency or sampling rate defines the number of samples per second taken from a continuous signal to make a discrete signal. ...
A cyclic redundancy check (CRC) is a type of hash function used to produce a checksum – a small, fixed number of bits – against a block of data, such as a packet of network traffic or a block of a computer file. ...
| Field Name | # of bits | Description | | syncword | 12 | 0xFFF | | ID | 1 | '1'=mpeg1 '0'=mpeg2 | | layer | 2 | '11'=1 '10'=2 '01'=3 | | protection | 1 | | | bitrate index | 4 | | | sampling frequency | 2 | KHz '00'=44.1 '01'=48 '10'=32 | | padding | 1 | | | private | 1 | | | mode | 2 | '00'=Stereo '01'=joint stereo '10'=dual channel '11'=single channel | | mode extension | 2 | | | copyright | 1 | 0=none 1=yes | | original or copy | 1 | 0=copy 1=origininal | | emphasis | 2 | | Although most of this information may be the same for all frames, MPEG decided to give each audio frame such a header in order to simplify synchronization and bitstream editing. The sampling frequency or sampling rate defines the number of samples per second taken from a continuous signal to make a discrete signal. ...
See also MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format, designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. ...
Defined by MPEG communication protocol. ...
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