dmxmus: demuxer for MUS files from the DMX audio library

NEWS

@@ -40,6 +40,7 @@ Demuxer:
  * Support for DAV video files
  * Improved Bluray menus, clips and stream selection
  * Support chapters in mp3 files
+ * Support for DMX audio music (MUS) files
 
 Codecs:
  * Support for experimental AV1 video encoding

modules/demux/Makefile.am

@@ -109,6 +109,9 @@ demux_LTLIBRARIES += libdemux_cdg_plugin.la
 libsmf_plugin_la_SOURCES = demux/smf.c
 demux_LTLIBRARIES += libsmf_plugin.la
 
+libdmxmus_plugin_la_SOURCES = demux/dmxmus.c
+demux_LTLIBRARIES += libdmxmus_plugin.la
+
 libgme_plugin_la_SOURCES = demux/gme.c
 libgme_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(demuxdir)'
 libgme_plugin_la_LIBADD = $(LIBS_gme)

modules/demux/dmxmus.c

@@ -0,0 +1,342 @@
+/*****************************************************************************
+ * dmxmus.c : DMX audio music (.mus) demux module for vlc
+ *****************************************************************************
+ * Copyright © 2019 Rémi Denis-Courmont
+ *
+ * Perusing documentation by Vladimir Arnost and Adam Nielsen.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+#include <string.h>
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_demux.h>
+
+typedef struct
+{
+    es_out_id_t *es;
+    date_t pts; /*< Play timestamp */
+    vlc_tick_t tick; /*< Last tick timestamp */
+    unsigned primaries:4;
+    unsigned secondaries:3;
+    unsigned end_offset:17;
+    unsigned char last_volume[16];
+} demux_sys_t;
+
+static block_t *Event2(uint8_t type, uint8_t channel, uint8_t data)
+{
+    block_t *ev = block_Alloc(2);
+    if (likely(ev != NULL)) {
+        ev->p_buffer[0] = type | channel;
+        ev->p_buffer[1] = data;
+    }
+    return ev;
+}
+
+static block_t *Event3(uint8_t type, uint8_t channel,
+                       uint8_t data, uint8_t data2)
+{
+    block_t *ev = block_Alloc(3);
+    if (likely(ev != NULL)) {
+        ev->p_buffer[0] = type | channel;
+        ev->p_buffer[1] = data;
+        ev->p_buffer[2] = data2;
+    }
+    return ev;
+}
+
+static block_t *HandleControl(demux_t *demux, uint8_t channel, uint8_t num)
+{
+    block_t *ev = NULL;
+
+    switch (num & 0x7f) {
+        case 10: /* sound off */
+            return Event3(0xB0, channel, 120, 0);
+
+        case 11: /* notes off */
+            return Event3(0xB0, channel, 123, 0);
+
+        case 12:
+        case 13:
+            break; /* only meaningful for OPL3, not soft synth */
+
+        case 14: /* reset all */
+            return Event3(0xB0, channel, 121, 0);
+
+        case 15: /* dummy */
+            break;
+
+        default:
+            msg_Warn(demux, "unknown control %u", num & 0x7f);
+    }
+
+    return ev;
+}
+
+static block_t *HandleControlValue(demux_t *demux, uint8_t channel,
+                                   uint8_t num, uint8_t val)
+{
+    val &= 0x7f;
+
+    switch (num & 0x7f) {
+        case 0: /* change program */
+            return Event2(0xC0, channel, val);
+
+        case 2: /* modulation */
+            return Event3(0xB0, channel, 1, val);
+
+        case 3: /* volume */
+            return Event3(0xB0, channel, 7, val);
+
+        case 4: /* pan */
+            return Event3(0xB0, channel, 10, val);
+
+        case 5: /* expression */
+            return Event3(0xB0, channel, 11, val);
+
+        case 6: /* reverberation */
+            return Event3(0xB0, channel, 91, val);
+
+        case 7: /* chorus */
+            return Event3(0xB0, channel, 93, val);
+
+        case 8: /* pedal hold */
+            return Event3(0xB0, channel, 64, val);
+
+        case 9: /* pedal soft */
+            return Event3(0xB0, channel, 67, val);
+
+        case 1:
+        default:
+            return HandleControl(demux, channel, num);
+    }
+}
+
+static int Demux(demux_t *demux)
+{
+    stream_t *stream = demux->s;
+    demux_sys_t *sys = demux->p_sys;
+
+    if (vlc_stream_Tell(stream) >= sys->end_offset)
+        return VLC_DEMUXER_EOF;
+    /* We might overflow the end offset by 2 bytes. Not really a problem. */
+
+    /* Inject the MIDI Tick every 10 ms */
+    if (sys->tick < date_Get(&sys->pts)) {
+        block_t *tick = block_Alloc(1);
+        if (unlikely(tick == NULL))
+            return VLC_ENOMEM;
+
+        tick->p_buffer[0] = 0xF9;
+        tick->i_dts = tick->i_pts = sys->tick;
+
+        es_out_Send(demux->out, sys->es, tick);
+        es_out_SetPCR(demux->out, sys->tick);
+
+        sys->tick += VLC_TICK_FROM_MS(10);
+        return VLC_DEMUXER_SUCCESS;
+    }
+
+    /* Read one MIDI event */
+    block_t *ev = NULL;
+    unsigned char byte, data;
+
+    if (vlc_stream_Read(stream, &byte, 1) < 1)
+        return VLC_DEMUXER_EGENERIC;
+
+    uint_fast8_t type = (byte >> 4) & 0x7;
+    uint_fast8_t channel = byte & 0xf;
+
+    if (type != 5 && type != 6 && vlc_stream_Read(stream, &data, 1) < 1)
+        return VLC_DEMUXER_EGENERIC;
+
+    if (channel >= ((channel < 10) ? sys->primaries : (10 + sys->secondaries)))
+        channel = 9;
+
+    switch (type) {
+        case 0: /* release note */
+            ev = Event2(0x80, channel, data & 0x7f);
+            break;
+
+        case 1: { /* play note */
+            uint8_t vol;
+
+            if (data & 0x80) {
+                if (vlc_stream_Read(stream, &vol, 1) < 1)
+                    return VLC_DEMUXER_EGENERIC;
+
+                vol &= 0x7f;
+                sys->last_volume[channel] = vol;
+            } else
+                vol = sys->last_volume[channel];
+
+            ev = Event3(0x90, channel, data & 0x7f, vol);
+            break;
+        }
+
+        case 2: /* pitch bend */
+            ev = Event3(0xE0, channel, (data << 6) & 0x7f, (data >> 1) & 0x7f);
+            break;
+
+        case 3: /* control w/o value */
+            ev = HandleControl(demux, channel, data);
+            break;
+
+        case 4: { /* control w/ value */
+            uint8_t val;
+
+            if (vlc_stream_Read(stream, &val, 1) < 1)
+                return VLC_DEMUXER_EGENERIC;
+
+            ev = HandleControlValue(demux, channel, data, val);
+            break;
+        }
+
+        case 5: /* end of measure */
+            break;
+
+        case 6: /* end of track */
+            return VLC_DEMUXER_EOF;
+
+        case 7: /* dummy */
+            break;
+
+        default:
+            vlc_assert_unreachable();
+    }
+
+    if (ev != NULL) {
+        ev->i_pts = ev->i_dts = date_Get(&sys->pts);
+        es_out_Send(demux->out, sys->es, ev);
+    }
+
+    /* Compute delay until next event */
+    uint32_t delay = 0;
+
+    while (byte & 0x80) {
+        if (vlc_stream_Read(stream, &byte, 1) < 1)
+            return VLC_DEMUXER_EGENERIC;
+
+        delay <<= 7;
+        delay |= byte & 0x7f;
+    }
+
+    date_Increment(&sys->pts, delay);
+    return VLC_DEMUXER_SUCCESS;
+}
+
+static int Control(demux_t *demux, int query, va_list args)
+{
+    demux_sys_t *sys = demux->p_sys;
+
+    switch (query) {
+        case DEMUX_CAN_SEEK:
+            *va_arg(args, bool *) = false; /* TODO */
+            break;
+
+        case DEMUX_GET_POSITION:
+        case DEMUX_SET_POSITION:
+        case DEMUX_GET_LENGTH:
+            return VLC_EGENERIC;
+
+        case DEMUX_GET_TIME:
+            *va_arg(args, vlc_tick_t *) = date_Get(&sys->pts) - VLC_TICK_0;
+            break;
+
+        case DEMUX_SET_TIME:
+            return VLC_EGENERIC;
+
+        case DEMUX_CAN_PAUSE:
+        case DEMUX_SET_PAUSE_STATE:
+        case DEMUX_CAN_CONTROL_PACE:
+        case DEMUX_GET_PTS_DELAY:
+            return demux_vaControlHelper(demux->s, 0, -1, 0, 1, query, args);
+
+        default:
+            return VLC_EGENERIC;
+    }
+    return VLC_SUCCESS;
+}
+
+static int Open(vlc_object_t *obj)
+{
+    demux_t *demux = (demux_t *)obj;
+    stream_t *stream = demux->s;
+    const uint8_t *hdr;
+
+    if (vlc_stream_Peek(stream, &hdr, 16) < 16)
+        return VLC_EGENERIC;
+    if (memcmp(hdr, "MUS\x1A", 4))
+        return VLC_EGENERIC;
+
+    uint_fast16_t length = GetWLE(hdr + 4);
+    uint_fast16_t offset = GetWLE(hdr + 6);
+    uint_fast16_t primaries = GetWLE(hdr + 8);
+    uint_fast16_t secondaries = GetWLE(hdr + 10);
+
+    if (primaries > 8 || secondaries > 5)
+        return VLC_EGENERIC;
+
+    /* Ignore the patch list and jump to the event offset. */
+    size_t instc = GetWLE(hdr + 12);
+    size_t hdrlen = 16 + 2 * instc;
+
+    if (offset < hdrlen
+     || vlc_stream_Read(stream, NULL, offset) < (ssize_t)offset)
+        return VLC_EGENERIC;
+
+    msg_Dbg(demux, "MIDI channels: %u primary, %u secondary",
+            GetWLE(hdr + 8), GetWLE(hdr + 10));
+
+    demux_sys_t *sys = vlc_obj_malloc(obj, sizeof (*sys));
+    if (unlikely(sys == NULL))
+        return VLC_ENOMEM;
+
+    sys->end_offset = (uint_fast32_t)offset + (uint_fast32_t)length;
+    sys->primaries = primaries;
+    sys->secondaries = secondaries;
+    memset(sys->last_volume, 0, sizeof (sys->last_volume));
+
+    es_format_t fmt;
+
+    es_format_Init(&fmt, AUDIO_ES, VLC_CODEC_MIDI);
+    fmt.audio.i_channels = 2;
+    fmt.audio.i_rate = 44100;
+    sys->es = es_out_Add(demux->out, &fmt);
+
+    date_Init(&sys->pts, 140, 1);
+    date_Set(&sys->pts, VLC_TICK_0);
+    sys->tick = VLC_TICK_0;
+
+    demux->p_sys = sys;
+    demux->pf_demux = Demux;
+    demux->pf_control = Control;
+    return VLC_SUCCESS;
+}
+
+vlc_module_begin()
+    set_description(N_("DMX music demuxer"))
+    set_category(CAT_INPUT)
+    set_subcategory(SUBCAT_INPUT_DEMUX)
+    set_capability("demux", 20)
+    set_callbacks(Open, NULL)
+vlc_module_end()