| Different Audio Formats |
|
The file compression has allowed the existence of file formats. These formats produce smaller files with the loss of an acceptable quality. This applies to several products, but among the most common uses are media files: audio and video. The application can then play these files on different media, such as portable devices (PCs, laptops, netbooks, mp3 players, cell phones, etc). It is consider perception because most of audio formats such as MP3, use characteristics of the human ear to design compression algorithms that shape a sound file. The human being does not recognize many of the sound frequencies that are captured during recording. These frequencies can be removed in a selective manner, as may be further enhanced sound frequencies that the ear, without significantly alter the quality of what we hear. The file size can be reduced by an average factor of 10 to 1. During the recording of a song, the sampling of sounds is made in high quality which means that the file size is quite big for a few minutes of audio. MPEG-1 Audio Layer 3, more commonly known as MP3 is a compressed digital audio format developed by Moving Picture Experts Group (MPEG) to form part of version 1 (and later expanded in version 2) format MPEG video. The mp3 standard is 44 kHz and a bitrate of 128 kbps by the ratio of quality / size. Compression can achieve a reduction of up to 12 times (ratio 12:1). Means that if a CDDA track occupies an area of approximately 40 to 50 MB (length of track), in MP3 format only take 4-5 MB, apparently getting the same quality digital audio without apparent loss. MP4 MPEG-4 Part 14 or *. MP4 is a file format specified as part of the international standard MPEG-4 ISO / IEC. It is used for storing audio-visual formats specified by ISO / IEC and the group MPEG (Moving Picture Experts Group). Is typically used to store data in computer files, for transmitting audiovisual streams. This is a format that allows downloading files from the Internet and using encryption technologies developed by Fraunhofer Institute and companies like AT & T, Dolby and Sony, among others. This new work is the union between the AAC and TVQ Yamaha. To enjoy the compressed audio and video files, with the MP4 is not necessary to download any software that fulfills the role of player. This are just executable files, so you only need to open them with a media player. WAV WAV (or WAVE), apocopation for Waveform audio format, is an uncompressed digital data developed by Microsoft and IBM that is used to store sounds on the PC, supports mono and stereo files at various resolutions and sample rates . Is a variant form of RIFF (Resource Interchange File Format, file format for exchanging resources), the method for storage packages, and relatively similar to the IFF and the AIFF format used by Macintosh. The format takes into account some peculiarities of the Intel CPU, and is the main format used by Windows. Though the WAV format can handle almost any audio codec is used primarily to PCM format (not compressed) and having no loss of quality can be used by professionals. To get CD quality sound is required to be recorded at 44,100 Hz and 16 bits, so each minute of audio recording consumes about 10 MB of disk space. It has file size limitation (4GB), which equals approximately 6.6 hours as a compact disc. WMA Windows Media Audio (WMA) is an audio data compression format developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs. The original WMA codec, known simply as WMA, was conceived as a competitor to the popular mp3 and RealAudio codecs.WMA Pro, a newer and more advanced codec, supports multichannel and high resolution audio. A lossless codec, WMA Lossless, compresses audio data without loss of audio fidelity.This format is specifically related to Windows Media Video (WMV) and Advanced Streaming Format (ASF), both from Microsoft. OGG Vorbis Vorbis audio codec is a free lossy compression part of the Ogg project and then called Ogg Vorbis also for being the only ogg codec commonly found in the Ogg container. Vorbis is a perceptual audio codec designed to allow maximum encoder flexibility, allowing it to scale competitively over an exceptionally wide range of bitrates. On a scale of quality / bitrate (audio CD or DAT-rate stereo, 16/24 bits) is at the same level as MPEG-2 and Musepack (MPC) and comparable to AAC at most bitrates. Similarly, the encoder can encode 1.0 quality audio from CD, DAT-rate up to 48kbps stereo without lowering the sampling frequency, sampling frequencies from 8kHz telephony from low and even high-definition 192kHz, and a range of channel representations ( monaural, polyphonic, stereo, quadraphonic, 5.1, ambisónico or up to 255 discrete channels). DVD and audio formats With the arrival of DVD, new needs regarding the sound were necessary, to be oriented to movies rather than music. The sound should have six channels (front right, front left, center, rear right, rear left, bass), and more dynamism because unlike music, the sounds change abruptly. The three most common formats used in the DVD are PCM, which is directly uncompressed audio, AC3, employing MP2 with six channels, and DTS. While a DVD has a huge capacity, and one might think that it is best to introduce the uncompressed audio for a movie 90 minutes, with six channels, we would need 2.73 GB per language. Therefore, this format is used only in music DVDs. AC3, developed by Dolby Laboratories, also known as Dolby Digital, is the most used. It is basically an aggregation of up to six channels, tablets each with MP2 (the younger brother of MP3, with lower quality and less need for processor) and a half Bitrate of 384 kbps or 448 kbps. Thus, a film soundtrack can include multiple languages.
( 1 Vote ) |
