This format is more advanced than MP3, offering better audio quality, and files in this format are usually larger then MP3 files for the same content. Note 1: For Level 2 and 3, the folder are included in code with with command: addpath. AAC (Advanced Audio Coding) is a lossy audio compression format, based audio-encoding standard for MPEG-2 and MPEG-4.To validate the functionality, AAC is applied to the song Licor De Calandraca. Then each frame is encoded autonomously and therefore the finally encoded bitstream consists of the sequence of bits that correspond to the successive frames. More specifically, during coding the original audio signal (for us stereo with sampling 48000 samples/sec) is divided into 50% overlapping sections (frames) of 2048 samples. To reduce the excess information, AAC basically uses the transformation coding approach implemented using the so-called Modified Discrete Cosine Transform (MDCT) at the Filterbank stage, while for entropy coding it uses the Huffman coding implemented at the homonymous stage. For this reason the Psychoacoustic Model mechanism that guides the Quantizer mechanism plays a dominant role. The psychoacoustic model that allows the introduction of distortions of the signal (noise due to quantization) which is below the audibility threshold is used as a fidelity criterion. Advanced Audio Coding (AAC) is a commonly used lossy digital audio compression codec developed by MPEG (Moving Picture Experts Group). AAC allows for a very flexible selection of operating modes and configurations. AAC encoding and decoding belongs to the waveform compression category and attempts to represent the original signal in such a way that its decoded version sounds as similar as possible to the original signal. MPEG-2 Advanced Audio Coding (ISO/IEC 13818-7) is the newest and most powerful member of the MPEG family of high-quality, digital audio compression systems. Despite the simplifications, this version leads to quite good results. An exception is the psychoacoustic model, which is a slightly simplified version of MPEG AAC. The version presented in here is more like the 3GPP TS 26.403 specification where some processing steps are missing. Variations of the AAC are used by many international standards such as MPEG-2, MPEG-4, H.264 etc. AAC, especially MPEG-4 AAC, provides greater. It has some advantages over MP3 - it has a greater range of sample frequencies, up to 48 channels and higher coding efficiency. It has many options and is heavily customisable depending on the desired output. The work aims to implement an Advanced Audio Coding (AAC) encoder/decoder. (Advanced Audio Coding) An audio compression technology that is part of the MPEG-2 and MPEG-4 standards. AAC actually refers to two similar codecs - MPEG-2 Part 7 (Advanced Audio Coding) and MPEG-4 Part 3.
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