![]() ![]() Upon decoding, the output is, to varying degrees, still understandable. They strip away audio frequencies that aren't used much, tolerate loss of precision in the decoded output, and use other methods to lose audio content, quality, and fidelity to produce smaller encoded media. Lossy codecs, on the other hand, take advantage of the fact that the human ear is not a perfect interpreter of audio, and of the fact that the human brain can pluck the important information out of imperfect or noisy audio. Upon decoding audio compressed with a lossless codec such as FLAC or ALAC, the result is identical in every way to the original sound, down to the bit. Lossless compression algorithms reduce the size of the audio without compromising the quality or fidelity of the sound. There are two basic categories of audio compression. Some of these are a matter of the form of the source audio others are related to decisions made while encoding the audio. Several factors affect the size of the encoded audio. The parameters available-and the range of possible values-varies from codec to codec, and even among different encoding utilities for the same codec, so read the documentation that comes with the encoding software you use to learn more. Joint stereo can reduce the size of the encoded audio to some extent Removing frequency bands means less data to encode, thus smaller encoded If there is any audio in the removed frequency band(s), there may be a The higher the bit rate, the larger the encoded file is likely to be The higher the bit rate, the higher the quality can be The amount of change varies from codec to codec The higher the fidelity, the larger the resulting file becomes, though The higher the quality, the better the fidelity of the encoded audio Unlikely to get more than 40-50% compressionĪlways some loss of fidelity the higher the compression, the more the The effect of codec configuration on encoded audio outputĪudio encoder configuration effects on quality and size Feature For example, if the encoder is configured to reduce the sample rate, the sample rate's effect on the output file will be reduced in kind.įor more information about these and other features of audio data, see Audio data format and structure in Digital audio concepts. Of course, these effects can be altered by decisions made while encoding the audio. Source detail may make the encoded file larger it will never make it That may or may not be the same as the original sample size. Resulting in more accurate representation of each sample.ĭepends on the codec codecs typically have an internal sample format The larger the samples, the more detail each sample can contain, Increasing the sample rate increases the encoded audio file's size. ![]() The more samples available per second, the higher the resulting encoded Generally reduces the amount of compression which is possible. ![]() Hiss, static, or background noise increases the audio complexity, which ![]() Reduce in size while maintaining precision). Making the audio waveform more complicated and therefore difficult to Unwanted background noise or hiss tends to reduce audio quality bothĭirectly (by masking details of the foreground audio) and indirectly (by The number of channels affects only the perception of directionality,Įach channel may substantially increase the encoded audio size,ĭepending on contents and encoder settings. The effect of source audio format and contents on the encoded audio quality See Codecs used by WebRTC for details.įor information about the fundamental concepts behind how digital audio works, see the article Digital audio concepts. In this article, we look at audio codecs used on the web to compress and decompress audio, what their capabilities and use cases are, and offer guidance when choosing audio codecs to use for your content.Īdditionally, WebRTC implementations generally use a subset of these codecs for their encoding and decoding of media, and may support additional codecs as well, for optimal cross-platform support of video and audio conferencing, and to integrate better with legacy telecommunication solutions. The processing of audio data to encode and decode it is handled by an audio codec ( COder/ DECoder). For web developers, an even bigger concern is the network bandwidth needed in order to transfer audio, whether for streaming or to download it for use during gameplay. Even modest quality, high-fidelity stereo sound can use a substantial amount of disk space. ![]()
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