Rendered MIDI file's audio export files are too long

[ReinholdH]

FluidSynth version

fluidsynth 2.3.1 and higher

Describe the bug

Rendered MIDI file's audio export files are too long

Expected behavior

This is a regression which came in with fluidsynth 2.3.1. The MIDI file Dance.mid is 1:36 long. But with fuidsynth 2.3.1 onwards an audio export file is 2:05 long. Between 1:36 and 2:05 there is silence.
At a first glance my gut feeling tells me that the regression came in with #1159 in fluidsynth 2.3.1 but I need to further investigate.

Steps to reproduce

Render the file Dance.mid from here into a wav file. Listen the exported wav files "dance - 16bit.wav" and "dance - 32bit.flac" from here

Additional context

Between 1:36 and 2:05 there is silence. In previous fluidsynth versions before 2.3.1, the exported wav files have the correct duration. The demos were created by es20490446e as part of #1405

[ReinholdH]

Yes, the culprit is #1159.

Extending the playing in fluid_midi.c by (Code snippet from fluid_midi.c of fluidsynth 2.3.1)

    /* Once we've run out of MIDI events, keep playing until no voices are active */
    if(status == FLUID_PLAYER_DONE && fluid_synth_get_active_voice_count(player->synth) > 0)
    {
        /* The first time we notice we've run out of MIDI events but there are still active voices, disable all hold pedals */
        if(!player->end_pedals_disabled)
        {
            for(i = 0; i < synth->midi_channels; i++)
            {
                fluid_synth_cc(player->synth, i, SUSTAIN_SWITCH, 0);
                fluid_synth_cc(player->synth, i, SOSTENUTO_SWITCH, 0);
            }

            player->end_pedals_disabled = 1;
        }

        status = FLUID_PLAYER_PLAYING;
    }

causes the problem. Since 2.3.1 there have been further changes in this area which need to be validated.

The demo MIDI file Dance.mid is not only causing the problem. I tested other MIDI files, too. For all the tested MIDI files the duration is not properly determined. Some are 12 seconds longer, some 18 seconds, some even 1/2 minute like Dance.mid.
I come to the conclusion that this solution here is not appropriate. This regression bug is a showstopper for us.

[ReinholdH]

For the MIDI file Dance.mid I did a deep dive in fluid_player_callback. Here are my findings:

At FLUID_PLAYER_DONE: msec = 94000 = 1:34 which is the correct end of the MIDI file
At no voices active: msec = 123251 = 2:03
Final end: 2:03 + FLUID_PLAYER_STOP_GRACE_MS = 2:05 what we see as the duration of the audio export.

Looks like that the criteria "no voices active" isn't the right criteria to keep player running. My 2 cents...

[ReinholdH]

For completeness because the link above to download the MIDI file Dance.mid is off-line meanwhile. Dance.mid can be downloaded as part of the GeneralUse GS 2.0.0 package from here.

[ReinholdH]

The issue is a general fluidsynth MIDI Player one not only relevant for file export. The basic MIDI Player from here (w/o reverb and chorus) plays for 2:05 long and not for 1:36. File rendering for audio export just makes the bug obvious.