Bitrate is indicated as one of the main characteristics of video and audio recordings. Most users are used to thinking that it determines the quality of the downloaded file. But what are bitrates, and how do they actually characterize music files and videos? Let's take a closer look at this.
What are bitrates?
Bitrate is a value that displays the number of units of information (megabits or kilobits) contained in one second of file playback. Accordingly, it is measured in megabits per second (Mbps) or kilobits per second (Kbps). Otherwise, the bitrate can be described as the bandwidth. This characteristic is important for those who want to convert files, because for the same duration, a larger bitrate will result in a larger file. In addition to the size, the sound quality also changes. Reducing the size when the bitrate is lowered is called compression.
The popular MP3 music format is an audio file compressed to such an extent that up to 12 hours of music can fit on a standard disc. However, the quality remainshigh due to psychoacoustic compression: sounds with frequencies and volume levels that are not picked up by the human ear are removed from the entire range. The selected sounds are formed into separate blocks called frames. Frames have the same sound duration and are compressed according to a given algorithm. When music is played, the signal is recreated from the decoded blocks in a certain sequence.
What is commonly used compression?
Audio bitrate is most often 256 Kbps. This setting compresses the audio recording approximately 6 times in size, allowing up to 6 times more music to be recorded on one disc than before compression. If the bitrate is lowered to 128 Kbps, then 12 times more music will fit on one disc, but the sound quality will be noticeably lower. Music recorded at 128 Kbps is most often offered for listening on the Internet, because in the pursuit of increasing page loading speed, resource owners make any sacrifices. Many users note that its quality is far from ideal.
Now that it became clear what bitrates are, it's time to determine their optimal level. Amateurs and professionals alike argue endlessly about how bitrate affects sound quality, and whether it does at all. On music albums, as a rule, the bitrate is indicated. The same disc recorded in 128Kbps and 256Kbps will cost twice as much.
Optimal bitrate under different listening conditions
For many people12x compression does not present any damage, while others claim that they cannot listen to music with a bit rate lower than 320 kbps. Paradoxically, both are right. The fact is that in the end, the quality of playback does not depend on the degree of compression, but on the playback conditions and even on the type of music.
For example, a song is played on a tape recorder installed in a domestic car. In this case, the quality at the level of 192 Kbps will be quite sufficient. A higher bit rate will improve the sound quality, but the difference will not be noticeable due to the high noise level during the trip. If the music is played on a home computer or portable player, then at least 256 Kbps is required. If the signal is not subject to changes, is transmitted to external devices and output to expensive imported speakers, then, if possible, resort to minimal compression. It is possible with a bitrate of 320 Kbps.
Optimal bitrate for various music styles
Music with a high bitrate is not always needed. Popular music tends to sound good enough at 192-256 kbps. Higher quality can be set, but there is no point in this: pop songs are short-lived, so saving disk space should be a priority. In addition, the quality of the original recordings is also mediocre, so increasing the bitrate may not affect the quality of the file being played. For listening in transport and at unofficial parties, average quality is enough.
If we are talking about classical music, the works of legendary rock bands or rare author's songs, then the quality should be above all. When purchasing such music, you need to look at the bitrate indicated on the disc packaging. If the song is downloaded from the Internet, then such information must be present on the download page. In addition, the bitrate is displayed in the player during playback.
Video file bitrates
It was said above what the bitrates of audio recordings are. But what is video bitrate? Considering that video is played as a sequence of sounds and images, the definition of bitrate will be similar. The presence of a video sequence makes the file heavier, but in the end, images for the processor are the same zeros and ones as sounds. The principle of information encryption is the same for all types of files.
