![]() (Programs like AudioIdentifier are not reliable at detecting transcodes.)įor example, the spectral below is of a FLAC file: the file extension is. The only way to verify that this song is truly a lossless file and not a transcoded file is by looking at its spectral. How are spectrals helpful when trying to detect transcodes? Say you download a song in FLAC from a blog. MP3 128kbps (CBR) has a frequency cut-off at 16 kHz. MP3 V2 has a frequency cut-off at 18.5 kHz. MP3 192kbps (CBR) has a frequency cut-off at 19 kHz. MP3 V0 has a frequency cut-off at 19.5 kHz. MP3 256kbps (CBR) has a frequency cut-off at 20 kHz. MP3 320kbps (CBR) has a frequency cut-off at 20.5 kHz. MP3s also tend to have a "shelf" at 16 kHz (you'll see it in the spectrals). MP3ĭifferent types of MP3s have different frequency cut-offs. It looks much different, right? But it's still a lossless spectral! Notice how "white noise" (the light purple) still extends to 22 kHz, even though those frequencies aren't used. The example above was a pop song, so most of the frequencies were represented. However, different genres have different-looking spectrals. Since lossless to lossless transcoding preserves all of the data in a music file, the spectral of a lossless song will look the same in FLAC, WAV (PCM), ALAC, etc. Songs on a retail CD and lossless songs have frequencies that extend all the way to 22 kHz. Every file has a relatively standard frequency cut-off.Ĭlick on any of the spectrals below to view it in a higher resolution. Since spectrals show all the data in a file, they are helpful tools to use when you're trying to decide whether or not a song has been transcoded. Humans have a hearing range from about 20 Hz - 20kHz (20,000 Hz). Frequencies are measured in hertz (Hz) and kilohertz (1,000 Hz). All of the frequencies are displayed on a spectral diagram ("spectral" for short), which is a graph of all the frequencies vs. Every music note has a specific frequency: lower notes have lower frequencies and higher notes have higher frequencies. Spectral analysis is a visual way to display the data in a music file.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |