Exemple #1
0
def managed_transition_helper(track1, track2, state, xfade=0, itrim1=0.0, otrim1=0.0, itrim2=0.0, maxlen=None, mode='equal_power', audition_hack=False): 
    """Manage the transition from one track to another

    Most of the parameters should be provided by keyword (in Py3, there'd be * after state).
    state: State mapping - cursor position etc is maintained here
    xfade: Number of tatums/segments to crossfade over
    itrim1: Initial trim of first track - ignored unless starting fresh
    otrim1: Trim end of first track - all these are floating-point seconds
    itrim2: Trim beginning of second track
    maxlen: If set, mix duration will be capped to this (protect against over-long transition)
    mode: Either equal_power or linear
    audition_hack: If set, cursor position will be reduced by the fade length. Yep, it's a hack.
    """
    if "cursor" not in state: 
        state["cursor"] = 0
        log.info("Cursor NOT IN STATE.")
    else:
        log.info(state)
    for track in (track1, track2):
        loudness = track.analysis.loudness
        track.gain = db_2_volume(loudness)
    # NOTE: All values are floating-point seconds, save xfade which is a number
    # of tatums/segments (assumed to be at average length).
    t1start = first_viable(track1) + itrim1
    t1end = last_viable(track1) - otrim1
    t2start = first_viable(track2) + itrim2
    # offset between start and first theoretical beat.
    t2offset = lead_in(track2)
    if xfade == 0:
        # Ensure that we always crossfade at least a little bit
        fade = 0.0001
        # Don't allow difference between track start and first beat to prevent hard transition.
        t2offset = 0
    else:
        # The crossfade is defined based on the tempo at the end
        # of the song, and we fade across X tatums/segments.
        avg_duration = avg_end_duration(track1)
        fade = avg_duration * xfade
    if audition_hack: 
        log.debug(state['cursor'])
        state['cursor'] -= fade
        log.debug("Audition hack")
        log.debug(state['cursor'])
    playback_end = t1end - fade - t2offset
    playback_duration = playback_end - state['cursor']
    mix_duration = t1end - playback_end
    log.info(mix_duration)

    if maxlen is not None:
        # Protect from xfade longer than second track.
        while mix_duration > maxlen:
            # Chop half a second at a time (not sure why, but let's maintain it for now)
            mix_duration -= .5
            playback_end += .5
            playback_duration += .5
    pb1 = pb(track1, state['cursor'], playback_duration)
    pb2 = cf((track1, track2), (playback_end - .01, t2start), mix_duration, mode=mode)
    state['cursor'] = mix_duration + t2start
    return [pb1, pb2]
Exemple #2
0
def managed_transition(track1, track2, xfade=0, otrim=0.0, itrim=0.0):
	state = {"cursor": track1.analysis.duration - 6.0 - float(otrim)}
	ret = managed_transition_helper(track1, track2, state,
		xfade=int(xfade),
		otrim1=float(otrim),
		itrim2=float(itrim),
		maxlen=float(track2.analysis.duration),
		audition_hack=True,
	)
	ret.append(pb(track2, state['cursor'], 6))
	print("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")
	print(ret)
	return ret
Exemple #3
0
def format_track(track, itrim=0.0, otrim=0.0, fadeout=5):
    playback = pb(track, itrim, track.analysis.duration - otrim)
    fade = fo(track, track.analysis.duration - otrim, fadeout)
    return [playback, fade]