1 /*****************************************************************************
2 * smf.c : Standard MIDI File (.mid) demux module for vlc
3 *****************************************************************************
4 * Copyright © 2007 Rémi Denis-Courmont
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU Lesser General Public License as published by
9 * the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this program; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
20 *****************************************************************************/
26 #include <vlc_common.h>
27 #include <vlc_plugin.h>
28 #include <vlc_demux.h>
29 #include <vlc_charset.h>
35 #define TEMPO_MAX 250 /* Beats per minute */
38 * Reads MIDI variable length (7, 14, 21 or 28 bits) integer.
39 * @return read value, or -1 on EOF/error.
41 static int32_t ReadVarInt (stream_t *s)
46 for (unsigned i = 0; i < 4; i++)
48 if (stream_Read (s, &byte, 1) < 1)
51 val = (val << 7) | (byte & 0x7f);
52 if ((byte & 0x80) == 0)
59 typedef struct smf_track_t
61 uint64_t next; /*< Time of next message (in term of pulses) */
62 int64_t start; /*< Start offset in the file */
63 uint32_t length; /*< Bytes length */
64 uint32_t offset; /*< Read offset relative to the start offset */
65 uint8_t running_event; /*< Running (previous) event */
69 * Reads (delta) time from the next event of a given track.
70 * @param s stream to read data from (must be positioned at the right offset)
72 static int ReadDeltaTime (stream_t *s, mtrk_t *track)
76 assert (stream_Tell (s) == track->start + track->offset);
78 if (track->offset >= track->length)
80 /* This track is done */
81 track->next = UINT64_MAX;
85 delta_time = ReadVarInt (s);
89 track->next += delta_time;
90 track->offset = stream_Tell (s) - track->start;
97 date_t pts; /*< Play timestamp */
98 uint64_t pulse; /*< Pulses counter */
99 mtime_t tick; /*< Last tick timestamp */
101 mtime_t duration; /*< Total duration */
102 unsigned ppqn; /*< Pulses Per Quarter Note */
103 /* by the way, "quarter note" is "noire" in French */
105 unsigned trackc; /*< Number of tracks */
106 mtrk_t trackv[]; /*< Track states */
110 * Non-MIDI Meta events handler
113 int HandleMeta (demux_t *p_demux, mtrk_t *tr)
115 stream_t *s = p_demux->s;
116 demux_sys_t *p_sys = p_demux->p_sys;
122 if (stream_Read (s, &type, 1) != 1)
125 length = ReadVarInt (s);
129 payload = malloc (length + 1);
130 if ((payload == NULL)
131 || (stream_Read (s, payload, length) != length))
137 payload[length] = '\0';
141 case 0x00: /* Sequence Number */
144 case 0x01: /* Text (comment) */
145 EnsureUTF8 ((char *)payload);
146 msg_Info (p_demux, "Text : %s", (char *)payload);
149 case 0x02: /* Copyright */
150 EnsureUTF8 ((char *)payload);
151 msg_Info (p_demux, "Copyright : %s", (char *)payload);
154 case 0x03: /* Track name */
155 EnsureUTF8 ((char *)payload);
156 msg_Info (p_demux, "Track name: %s", (char *)payload);
159 case 0x04: /* Instrument name */
160 EnsureUTF8 ((char *)payload);
161 msg_Info (p_demux, "Instrument: %s", (char *)payload);
164 case 0x05: /* Lyric (one syllable) */
165 /*EnsureUTF8 ((char *)payload);*/
168 case 0x06: /* Marker text */
169 EnsureUTF8 ((char *)payload);
170 msg_Info (p_demux, "Marker : %s", (char *)payload);
172 case 0x07: /* Cue point (WAVE filename) */
173 EnsureUTF8 ((char *)payload);
174 msg_Info (p_demux, "Cue point : %s", (char *)payload);
177 case 0x08: /* Program/Patch name */
178 EnsureUTF8 ((char *)payload);
179 msg_Info (p_demux, "Patch name: %s", (char *)payload);
182 case 0x09: /* MIDI port name */
183 EnsureUTF8 ((char *)payload);
184 msg_Dbg (p_demux, "MIDI port : %s", (char *)payload);
187 case 0x2F: /* End of track */
188 if (tr->start + tr->length != stream_Tell (s))
190 msg_Err (p_demux, "misplaced end of track");
195 case 0x51: /* Tempo */
198 uint32_t uspqn = (payload[0] << 16)
199 | (payload[1] << 8) | payload[2];
200 unsigned tempo = 60 * 1000000 / (uspqn ? uspqn : 1);
201 msg_Dbg (p_demux, "tempo: %uus/qn -> %u BPM",
202 (unsigned)uspqn, tempo);
204 if (tempo < TEMPO_MIN)
206 msg_Warn (p_demux, "tempo too slow -> %u BPM", TEMPO_MIN);
210 if (tempo > TEMPO_MAX)
212 msg_Warn (p_demux, "tempo too fast -> %u BPM", TEMPO_MAX);
215 date_Change (&p_sys->pts, p_sys->ppqn * tempo, 60);
221 case 0x54: /* SMPTE offset */
223 msg_Warn (p_demux, "SMPTE offset not implemented");
228 case 0x58: /* Time signature */
235 case 0x59: /* Key signature */
242 case 0x7f: /* Proprietary event */
243 msg_Dbg (p_demux, "ignored proprietary SMF Meta Event (%d bytes)",
248 msg_Warn (p_demux, "unknown SMF Meta Event type 0x%02X (%d bytes)",
257 int HandleMessage (demux_t *p_demux, mtrk_t *tr, es_out_t *out)
259 stream_t *s = p_demux->s;
261 uint8_t first, event;
264 if (stream_Seek (s, tr->start + tr->offset)
265 || (stream_Read (s, &first, 1) != 1))
268 event = (first & 0x80) ? first : tr->running_event;
270 switch (event & 0xf0)
272 case 0xF0: /* System Exclusive */
275 case 0xF0: /* System Specific start */
276 case 0xF7: /* System Specific continuation */
278 /* Variable length followed by SysEx event data */
279 int32_t len = ReadVarInt (s);
283 block = stream_Block (s, len);
286 block = block_Realloc (block, 1, len);
289 block->p_buffer[0] = event;
292 case 0xFF: /* SMF Meta Event */
293 if (HandleMeta (p_demux, tr))
295 /* We MUST NOT pass this event forward. It would be
296 * confused as a MIDI Reset real-time event. */
307 /* We cannot handle undefined "common" (non-real-time)
308 * events inside SMF, as we cannot differentiate a
309 * one byte delta-time (< 0x80) from event data. */
324 /* FIXME: one message per block is very inefficient */
325 block = block_Alloc (1 + datalen);
329 block->p_buffer[0] = event;
332 stream_Read (s, block->p_buffer + 1, datalen);
338 msg_Err (p_demux, "malformatted MIDI event");
339 return -1; /* implicit running status requires non-empty payload */
342 block->p_buffer[1] = first;
344 stream_Read (s, block->p_buffer + 2, datalen - 1);
348 block->i_dts = block->i_pts = date_Get (&p_demux->p_sys->pts);
350 es_out_Send (out, p_demux->p_sys->es, block);
352 block_Release (block);
356 /* If event is not real-time, update running status */
357 tr->running_event = event;
359 tr->offset = stream_Tell (s) - tr->start;
363 static int SeekSet0 (demux_t *demux)
365 stream_t *stream = demux->s;
366 demux_sys_t *sys = demux->p_sys;
368 /* Default SMF tempo is 120BPM, i.e. half a second per quarter note */
369 date_Init (&sys->pts, sys->ppqn * 2, 1);
370 date_Set (&sys->pts, VLC_TS_0);
372 sys->tick = VLC_TS_0;
374 for (unsigned i = 0; i < sys->trackc; i++)
376 mtrk_t *tr = sys->trackv + i;
380 /* Why 0xF6 (Tuning Calibration)?
381 * Because it has zero bytes of data, so the parser will detect the
382 * error if the first event uses running status. */
383 tr->running_event = 0xF6;
385 if (stream_Seek (stream, tr->start)
386 || ReadDeltaTime (stream, tr))
388 msg_Err (demux, "fatal parsing error");
396 static int ReadEvents (demux_t *demux, uint64_t *restrict pulse,
399 uint64_t cur_pulse = *pulse, next_pulse = UINT64_MAX;
400 demux_sys_t *sys = demux->p_sys;
402 for (unsigned i = 0; i < sys->trackc; i++)
404 mtrk_t *track = sys->trackv + i;
406 while (track->next <= cur_pulse)
408 if (HandleMessage (demux, track, out)
409 || ReadDeltaTime (demux->s, track))
411 msg_Err (demux, "fatal parsing error");
416 if (next_pulse > track->next)
417 next_pulse = track->next;
420 if (next_pulse != UINT64_MAX)
421 date_Increment (&sys->pts, next_pulse - cur_pulse);
426 #define TICK (CLOCK_FREQ / 100)
428 /*****************************************************************************
429 * Demux: read chunks and send them to the synthesizer
430 *****************************************************************************
431 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
432 *****************************************************************************/
433 static int Demux (demux_t *demux)
435 demux_sys_t *sys = demux->p_sys;
437 /* MIDI Tick emulation (ping the decoder every 10ms) */
438 if (sys->tick <= date_Get (&sys->pts))
440 block_t *tick = block_Alloc (1);
441 if (unlikely(tick == NULL))
444 tick->p_buffer[0] = 0xF9;
445 tick->i_dts = tick->i_pts = sys->tick;
447 es_out_Send (demux->out, sys->es, tick);
448 es_out_Control (demux->out, ES_OUT_SET_PCR, sys->tick);
454 /* MIDI events in chronological order across all tracks */
455 uint64_t pulse = sys->pulse;
457 if (ReadEvents (demux, &pulse, demux->out))
460 if (pulse == UINT64_MAX)
461 return 0; /* all tracks are done */
467 static int Seek (demux_t *demux, mtime_t pts)
469 demux_sys_t *sys = demux->p_sys;
471 /* Rewind if needed */
472 if (pts < date_Get (&sys->pts) && SeekSet0 (demux))
476 uint64_t pulse = sys->pulse;
478 while (pts > date_Get (&sys->pts))
480 if (pulse == UINT64_MAX)
481 return VLC_SUCCESS; /* premature end */
482 if (ReadEvents (demux, &pulse, NULL))
487 sys->tick = ((date_Get (&sys->pts) - VLC_TS_0) / TICK) * TICK + VLC_TS_0;
491 /*****************************************************************************
493 *****************************************************************************/
494 static int Control (demux_t *demux, int i_query, va_list args)
496 demux_sys_t *sys = demux->p_sys;
500 case DEMUX_GET_POSITION:
503 *va_arg (args, double *) = (sys->tick - (double)VLC_TS_0)
506 case DEMUX_SET_POSITION:
507 return Seek (demux, va_arg (args, double) * sys->duration);
508 case DEMUX_GET_LENGTH:
509 *va_arg (args, int64_t *) = sys->duration;
512 *va_arg (args, int64_t *) = sys->tick - VLC_TS_0;
515 return Seek (demux, va_arg (args, int64_t));
523 * Probes file format and starts demuxing.
525 static int Open (vlc_object_t *obj)
527 demux_t *demux = (demux_t *)obj;
528 stream_t *stream = demux->s;
532 /* (Try to) parse the SMF header */
533 /* Header chunk always has 6 bytes payload */
534 if (stream_Peek (stream, &peek, 14) < 14)
537 /* Skip RIFF MIDI header if present */
538 if (!memcmp (peek, "RIFF", 4) && !memcmp (peek + 8, "RMID", 4))
540 uint32_t riff_len = GetDWLE (peek + 4);
542 msg_Dbg (demux, "detected RIFF MIDI file (%"PRIu32" bytes)", riff_len);
543 if ((stream_Read (stream, NULL, 12) < 12))
546 /* Look for the RIFF data chunk */
553 || (stream_Read (stream, chnk_hdr, 8) < 8))
557 chnk_len = GetDWLE (chnk_hdr + 4);
558 if (riff_len < chnk_len)
560 riff_len -= chnk_len;
562 if (!memcmp (chnk_hdr, "data", 4))
565 if (stream_Read (stream, NULL, chnk_len) < (ssize_t)chnk_len)
569 /* Read real SMF header. Assume RIFF data chunk length is proper. */
570 if (stream_Peek (stream, &peek, 14) < 14)
574 if (memcmp (peek, "MThd\x00\x00\x00\x06", 8))
578 /* First word: SMF type */
579 switch (GetWBE (peek))
588 /* We don't implement SMF2 (as do many) */
589 msg_Err (demux, "unsupported SMF file type %u", GetWBE (peek));
594 /* Second word: number of tracks */
595 unsigned tracks = GetWBE (peek);
597 if (!multitrack && (tracks != 1))
599 msg_Err (demux, "invalid SMF type 0 file");
603 msg_Dbg (demux, "detected Standard MIDI File (type %u) with %u track(s)",
606 /* Third/last word: timing */
607 unsigned ppqn = GetWBE (peek);
610 msg_Err (demux, "SMPTE timestamps not implemented");
615 msg_Dbg (demux, " %u pulses per quarter note", ppqn);
618 demux_sys_t *sys = malloc (sizeof (*sys) + (sizeof (mtrk_t) * tracks));
619 if (unlikely(sys == NULL))
622 /* We've had a valid SMF header - now skip it*/
623 if (stream_Read (stream, NULL, 14) < 14)
629 sys->trackc = tracks;
631 /* Prefetch track offsets */
632 for (unsigned i = 0; i < tracks; i++)
634 mtrk_t *tr = sys->trackv + i;
637 /* Seeking screws streaming up, but there is no way around this, as
638 * SMF1 tracks are performed simultaneously.
639 * Not a big deal as SMF1 are usually only a few kbytes anyway. */
640 if (i > 0 && stream_Seek (stream, tr[-1].start + tr[-1].length))
642 msg_Err (demux, "cannot build SMF index (corrupted file?)");
648 if (stream_Read (stream, head, 8) < 8)
650 /* FIXME: don't give up if we have at least one valid track */
651 msg_Err (demux, "incomplete SMF chunk, file is corrupted");
655 if (memcmp (head, "MTrk", 4) == 0)
658 msg_Dbg (demux, "skipping unknown SMF chunk");
659 stream_Read (stream, NULL, GetDWBE (head + 4));
662 tr->start = stream_Tell (stream);
663 tr->length = GetDWBE (head + 4);
667 if (stream_Control (stream, STREAM_CAN_FASTSEEK, &b) == 0 && b)
669 if (SeekSet0 (demux))
672 for (uint64_t pulse = 0; pulse != UINT64_MAX;)
673 if (ReadEvents (demux, &pulse, NULL))
676 sys->duration = date_Get (&sys->pts);
679 if (SeekSet0 (demux))
683 es_format_Init (&fmt, AUDIO_ES, VLC_CODEC_MIDI);
684 fmt.audio.i_channels = 2;
685 fmt.audio.i_rate = 44100; /* dummy value */
686 sys->es = es_out_Add (demux->out, &fmt);
688 demux->pf_demux = Demux;
689 demux->pf_control = Control;
698 * Releases allocate resources.
700 static void Close (vlc_object_t * p_this)
702 demux_t *p_demux = (demux_t *)p_this;
703 demux_sys_t *p_sys = p_demux->p_sys;
709 set_description (N_("SMF demuxer"))
710 set_category (CAT_INPUT)
711 set_subcategory (SUBCAT_INPUT_DEMUX)
712 set_capability ("demux", 20)
713 set_callbacks (Open, Close)