Calculate time in the song (e.g. in seconds) from a given beat and bpm of Ultrastar file

[ultrastar-deluxe]

Calculate time in the song (e.g. in seconds) from a given beat and bpm of Ultrastar file

[basisbit]

Best practice for BPM values in usdx files is to always use a multiple of the actual song BPM, so that it is between 200 and 400.
: 0 10 5 bla means the syllable bla with a pitch of 5 starts at beat 0 of the current sentence and ends at beat 10 of the current sentence.

[basisbit]

the mp3 file you are using, is that maybe encoded in variable bitrate?

[achimmihca]

The MP3 is irrelevant.
It's a file with 30 seconds of silence. You could also use any other mp3. The notes that are displayed in USDX will be the same because this only depends on the description of the notes in the Ultrastar txt file.

[basisbit]

time is relative in usdx and YASS. So, if you use a file with variable bitrate instead of coded bitrate, depending on ffmpeg version used, the pointers->timestamp conversion is off. In USDX, the current playback position of the played audio frame is what tells the code what the "current beat" in game is.

[basisbit]

I am just trying to understand why the values are off there. I quickly checked the relevant code in usdx and yes, your calculation should be correct.

[achimmihca]

Found the answer: http://yass-along.com/beats/

[achimmihca]

You can think of BPM in Ultrastar files not as "beats per minute" but "bars per minute" in four-four time (Viervierteltakt).
Thus, one has to multiply with 4, to get what is commonly known as "beats per minute".

Anyway, the position of notes in Ultrastar files is then given in "beats per minutes".

This fixes the mismatch I had in my calculation: 5 [s] / 4 = 1.25 [s]

[basisbit]

lol, never realized that before. Anyways, found that now in the code of USDX: https://github.com/UltraStar-Deluxe/USDX/blob/916a35c408214a35022e70b9e9629145f62803a2/src/base/USong.pas#L1742

[achimmihca]

Yeah, you have to know this to get it right...

Anyway, displying the lyrics is now in sync with the music in my prototype. Last important thing missing now is recording notes and giving points. Yay!