Why can VLC Media increase my pc’s volume to 200% while a movie, but my pc can only increase to 100% during regular use?
In: Technology
Sound is represented by values in a range. Lets say for example that it is stored as a series of samples with values between -1 and 1. A single sound wave would have the values go from positive to negative and back to positive. The louder the sound the more positive and negative the values are and the quieter sounds stay around 0. If the audio is recorded and encoded properly then the loudest sounds will use the entire range of values between -1 and 1. When these values are sent to the sound system it instructs it to output the loudest sounds it can. The volume control can only reduce the values making it sound more quiet. However if there is something not right with the recording or the encoding the sounds may be off and even the loudest sounds never goes above for example 0.6. This is why some audio players allow you to increase the volume above 100%. At 200% the sounds that are normally quiet with values between -0.5 and 0.5 will get multiplied so they are using the entire range of values between -1 and 1. But what happens if you turn the volume up to 200% when there are sounds above 0.5? In this case the output will contain values above 1 but the sound system can not output sounds at a higher volume. The simplest way is to just round these values down to 1. This is known as clipping and you have probably heard this because it distorts the output. But VLC does something a bit more advanced called compression where it makes sure there is no distortion. However it does mean that quiet sounds and loud sounds in the input is all being played as loud sounds.
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