When you load an audio clip into a trigger slot, Ardour applies some - heuristics to estimate its temo in beats per minute. If neither the file - name nor the metadata specify it, Ardour will use - minibpm to analyze - the file assuming it has a fixed tempo. + heuristics to estimate its temo in beats per minute. Unless a metadata + in the file source provides information, + minibpm is used + to analyze and detect the file's BPM.
- After estimating the tempo, Ardour will enable stretching for the clip - to make it match session's bpm at any given time. This means that should - session's tempo change over time (in either ramped or constant mode), - Ardour will re-stretch all audio clips to accomodate for that. + After tempo is estimated, the clip is time-stretched to match the + session's tempo map. This means that should session's tempo change over + time (in either ramped or constant mode), all audio clips will be + re-stretched to accomodate for that.
@@ -36,9 +36,8 @@
- This is where Ardour displays the estimated tempo rounded to the closest - integer. You can progressively divide or mutiply by two whatever Ardour - thinks is the original tempo. + This is where the estimated tempo is displayed. It can also + be progressively divided or mutiplied by two.
@@ -48,30 +47,23 @@
- If you divide the estimated clip's tempo by 2, you get 45bpm. Stretching it - back to 120bpm will make it sound faster. And multiplying the original - clip's tempo by 2 will make it 180bpm. Stretched down to 120bpm, the clip - will sound slower than it originally is. + If the estimated clip's tempo is divided by 2, stretching the resulted + 45bpm back to 120bpm will make the clip sound faster. Vice versa, + multiplying the original clip's tempo by 2 and then stretching it down + from 180bpm to 120bpm will make the clip sound slower than it originally is.
+ This control allows adjusting the estimated tempo in a finer manner, + by changing the amount of beats it takes to play the clip in the selected + trigger slot. The change is immediately displayed in the BPM field above. +
Itâs a hint to help you counting. FIXME
- -1) when a file is loaded, we infer its bpm either by minibpm's estimate, a flag in the filename, metadata (TBD) or other means
- -2) we assume the clip must have an integer number of beats in it (simplest case is a one-bar loop with 4 beats in it)
- -3) ...so we round to the nearest beat length, and set the tempo to *exactly* fit the sample-length into the assumed beat-length
- -4) the user may recognize a problem: "this was a 3/4 beat, which was rounded to 4 beats but it should have been 3"
- -5) if the user changes the beat-length, then the tempo is recalculated for use during stretching
- -6) someday, we will also allow the sample start and length to be adjusted in a trimmer, and that will also adjust the tempo
- -7) in all cases the user should be in final control; but our "internal" value for stretching are just sample-start and BPM, end of story
\ No newline at end of file ++ This is an estimate of the clip's length as measured in bars for two + popular time signatures: 4/4 and 3/4. +