When vinyl records existed, music was recorded in an analog way, nobody ever thought about the space they occupied, because the amount of information was not a variable that will be taken into account.
On the other hand, when a new technology appeared that would allow the audio to be digitized, the space occupied by such information did have relevance.
Especially when it was stored on desktop computers that had hard drives that had little space.
Then the idea arose to compress the music trying to discard information but always trying that this process would not be noticeable.
But an important part of the process that is used to compress music is based on volume.
The volume of the different sounds is measured assuming that when there is a louder sound, the other sounds nearby at that frequency can be eliminated without the human being noticing it.
And in general the process of eliminating information added to what has been called the war of the volume What made the songs to be recorded a higher volume each time, have generated that the collections of audio files have very large differences in loudness between one audio file and one audio file.
And this has made it necessary to normalize the volume and loudness of the audio either from the audio files or from the video files.
Because with the video files the same thing happens: the audio that accompanies the video is also compressed and the same loss of information is suffered by what the musical files.
Therefore it does not matter if it is an MP4 or an mp3 or any other audio or video format, it is most likely necessary to normalize the volume to obtain an adequate loudness.
This is why it is so common that even batch normalization is done.
In other words, many audio or video files are normalized at the same time because people have large audio or video connections that need loudness normalization to correct loudness and volume problems.
Mp4gain is the only and the most efficient program that has the ability to normalize the loudness of most of the audio and video formats.
In turn, mp4gain is an audio converter and a video converter and even a converter. What can extract audio from a video file AND transfer it to an audio format.
Extract the audio from an MP4 and convert it into an mp3 with high sound quality.
