Add shell commands to the MIDI File Player

[jjceresa]

Commands are:

• player_start Start playing from the beginning of current song
• player_stop Stop playing
• player_cont Continue playing
• player_step num Move forward/backward in current song to +/-num ticks
• player_next Move to next song
• player_loop num Set loop number to num (-1 = loop forever)
• player_tempo_bmp num Set tempo to num beats per minute

[jjceresa]

Please note that player_tempo_bpm command call actual bugged fluid_player_set_bpm(). Once fix-player-tempo branch (#711) will be merged into master, actual branch (this PR) will require to be updated and completed before merging it to master.

[derselbst]

We have some issues here:

• You cannot add additional arguements to the existing public API functions new_fluid_cmd_handler and new_fluid_server. Use recently introduced new_fluid_cmd_handler2 for this purpose and add a new_fluid_server2 function.
• You've changed the order of processing in fluidsynth.c: You're now executing the command file before having loaded a default soundfont. This will be problematic if the user relies on the default soundfont. If the user has noteon commands in his command file, those commands will now fail because no preset has been assigned yet.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[derselbst]

I just gave it a test and it works very well. Thanks!

[jjceresa]

I just gave it a test and it works very well.

Thanks for reviewing.