Change OpenTTD#6684: Looping/cutting points for music base sets

This fixes bad looping of title screen song from Windows TTD, and fixes
a long silence at the end of "Can't get there from here" from Windows TTD.

bin/baseset/orig_win.obm

@@ -142,5 +142,17 @@ GM_TT19.GM = Funk Central
 GM_TT20.GM = Jammit
 GM_TT21.GM = Movin' On
 
+; MIDI timecodes where the playback should attemp to start and stop short.
+; This is to allow fixing undesired silences in original MIDI files.
+; However not all music drivers may support this.
+[timingtrim]
+; Theme has two beats silence at the beginning which prevents clean looping.
+GM_TT00.GM = 768:53760
+; Can't Get There From Here from the Windows version has a long silence at the end,
+; followed by a solo repeat. This isn't in the original DOS version music and is likely
+; unintentional from the people who converted the music from the DOS version.
+; Actual song ends after measure 152.
+GM_TT10.GM = 0:235008
+
 [origin]
 default      = You can find it on your Transport Tycoon Deluxe CD-ROM.

media/baseset/orig_win.obm

@@ -90,5 +90,17 @@ GM_TT19.GM = Funk Central
 GM_TT20.GM = Jammit
 GM_TT21.GM = Movin' On
 
+; MIDI timecodes where the playback should attemp to start and stop short.
+; This is to allow fixing undesired silences in original MIDI files.
+; However not all music drivers may support this.
+[timingtrim]
+; Theme has two beats silence at the beginning which prevents clean looping.
+GM_TT00.GM = 768:53760
+; Can't Get There From Here from the Windows version has a long silence at the end,
+; followed by a solo repeat. This isn't in the original DOS version music and is likely
+; unintentional from the people who converted the music from the DOS version.
+; Actual song ends after measure 152.
+GM_TT10.GM = 0:235008
+
 [origin]
 default      = You can find it on your Transport Tycoon Deluxe CD-ROM.

src/base_media_base.h

@@ -301,6 +301,8 @@ struct MusicSongInfo {
 	const char *filename;
 	MusicTrackType filetype;
 	int cat_index;
+	int override_start;
+	int override_end;
 };
 
 /** All data of a music set. */

src/music.cpp

@@ -129,6 +129,7 @@ bool MusicSet::FillSetDetails(IniFile *ini, const char *path, const char *full_f
 
 		IniGroup *names = ini->GetGroup("names");
 		IniGroup *catindex = ini->GetGroup("catindex");
+		IniGroup *timingtrim = ini->GetGroup("timingtrim");
 		for (uint i = 0; i < lengthof(this->songinfo); i++) {
 			const char *filename = this->files[i].filename;
 			if (names == NULL || StrEmpty(filename)) {
@@ -154,15 +155,16 @@ bool MusicSet::FillSetDetails(IniFile *ini, const char *path, const char *full_f
 				this->songinfo[i].filetype = MTT_STANDARDMIDI;
 			}
 
+			const char *trimmed_filename = filename;
 			/* As we possibly add a path to the filename and we compare
 			 * on the filename with the path as in the .obm, we need to
 			 * keep stripping path elements until we find a match. */
-			for (const char *p = filename; p != NULL; p = strchr(p, PATHSEPCHAR)) {
+			for (; trimmed_filename != NULL; trimmed_filename = strchr(trimmed_filename, PATHSEPCHAR)) {
 				/* Remove possible double path separator characters from
 				 * the beginning, so we don't start reading e.g. root. */
-				while (*p == PATHSEPCHAR) p++;
+				while (*trimmed_filename == PATHSEPCHAR) trimmed_filename++;
 
-				item = names->GetItem(p, false);
+				item = names->GetItem(trimmed_filename, false);
 				if (item != NULL && !StrEmpty(item->value)) break;
 			}
 
@@ -176,7 +178,17 @@ bool MusicSet::FillSetDetails(IniFile *ini, const char *path, const char *full_f
 			}
 			this->num_available++;
 
+			/* if there is a theme song, number that one zero */
 			this->songinfo[i].tracknr = (i==0 && this->has_theme) ? 0 : next_track_nr++;
+
+			item = timingtrim->GetItem(trimmed_filename, false);
+			if (item != NULL && !StrEmpty(item->value)) {
+				const char *endpos = strchr(item->value, ':');
+				if (endpos != NULL) {
+					this->songinfo[i].override_start = atoi(item->value);
+					this->songinfo[i].override_end = atoi(endpos + 1);
+				}
+			}
 		}
 	}
 	return ret;

src/music/win32_m.cpp

@@ -286,8 +286,6 @@ void CALLBACK TimerCallback(UINT uTimerID, UINT, DWORD_PTR dwUser, DWORD_PTR, DW
 
 void MusicDriver_Win32::PlaySong(const MusicSongInfo &song)
 {
-	if (song.filetype != MTT_STANDARDMIDI) return;
-
 	DEBUG(driver, 2, "Win32-MIDI: PlaySong: entry");
 	EnterCriticalSection(&_midi.lock);