MIDI message decoder using Fluidsynth software synthetizer

NEWS

@@ -60,6 +60,7 @@ Input/Demuxers:
   * Improved ID3v2 tags support
   * Improved Ogg/Vorbis tags support
   * Raw video support
+  * Standard MIDI File (types 0 & 1) support
 
 Decoders:
  * VP60/VP61/VP6F/VP62 support
@@ -70,6 +71,7 @@ Decoders:
  * DosBox Capture support
  * Karl Morton's Video support
  * limited atrac3 support
+ * Fluidsynth MIDI software synthesis (with external sound fonts)
  * New codec FOURCCs to support more specific files:
    Avid, FCP, Sony, Samsung, ...
 

configure.ac

@@ -3779,6 +3779,23 @@ if test "${enable_x264}" != "no"; then
   fi
 fi
 
+dnl
+dnl libfluidsynth (MIDI synthetizer) plugin
+dnl
+AC_ARG_ENABLE(fluidsynth,
+  [  --enable-fluidsynth     MIDI synthesisr with libfluidsynth (default auto)])
+AS_IF([test "x${enable_fluidsynth}" != "xno"], [
+  PKG_CHECK_MODULES(FLUIDSYNTH, fluidsynth, [
+    VLC_ADD_PLUGINS(fluidsynth)
+    VLC_ADD_CFLAGS(fluidsynth, [${FLUIDSYNTH_CFLAGS}])
+    VLC_ADD_LDFLAGS(fluidsynth, [${FLUIDSYNTH_LIBS}])
+  ], [
+    AS_IF([test "x${enable_fluidsynth}" != "x"], [
+      AC_MSG_ERROR([${FLUIDSYNTH_PKG_ERRORS}])
+    ])
+  ])
+])
+
 dnl
 dnl Teletext Modules
 dnl vbi decoder plugin (using libzbvi)

modules/codec/Modules.am

@@ -30,3 +30,4 @@ SOURCES_realaudio = realaudio.c
 SOURCES_sdl_image = sdl_image.c
 SOURCES_zvbi = zvbi.c
 SOURCES_cdg = cdg.c
+SOURCES_fluidsynth = fluidsynth.c

modules/codec/fluidsynth.c

+/*****************************************************************************
+ * fluidsynth.c: Software MIDI synthetizer using libfluidsynth
+ *****************************************************************************
+ * Copyright © 2007 Rémi Denis-Courmont
+ * $Id$
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU 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.
+ *****************************************************************************/
+
+#include <vlc/vlc.h>
+#include <vlc_aout.h>
+#include <vlc_codec.h>
+
+#include <fluidsynth.h>
+
+#define SOUNDFONT_TEXT N_("Sound fonts (required)")
+#define SOUNDFONT_LONGTEXT N_( \
+    "A sound fonts file is required for software synthesis." )
+
+static int  Open  (vlc_object_t *);
+static void Close (vlc_object_t *);
+
+vlc_module_begin();
+    set_description (_("FluidSynth MIDI synthetizer"));
+    set_capability ("decoder", 100);
+    set_category (CAT_INPUT);
+    set_subcategory (SUBCAT_INPUT_ACODEC);
+    set_callbacks (Open, Close);
+    add_file ("soundfont", "", NULL,
+              SOUNDFONT_TEXT, SOUNDFONT_LONGTEXT, VLC_FALSE);
+vlc_module_end();
+
+
+struct decoder_sys_t
+{
+    fluid_settings_t *settings;
+    fluid_synth_t    *synth;
+    int               soundfont;
+    audio_date_t      end_date;
+};
+
+
+static aout_buffer_t *DecodeBlock (decoder_t *p_dec, block_t **pp_block);
+
+
+static int Open (vlc_object_t *p_this)
+{
+    decoder_t *p_dec = (decoder_t *)p_this;
+    decoder_sys_t *p_sys;
+
+    if (p_dec->fmt_in.i_codec != VLC_FOURCC ('M', 'I', 'D', 'I'))
+        return VLC_EGENERIC;
+
+    char *font_path = var_CreateGetNonEmptyString (p_this, "soundfont");
+    if (font_path == NULL)
+    {
+        msg_Err (p_this, "sound fonts file required for synthesis");
+        return VLC_EGENERIC;
+    }
+
+    p_dec->fmt_out.i_cat = AUDIO_ES;
+    p_dec->fmt_out.audio.i_rate = 44100;
+    p_dec->fmt_out.audio.i_channels = 2;
+    p_dec->fmt_out.audio.i_original_channels =
+    p_dec->fmt_out.audio.i_physical_channels =
+        AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
+    p_dec->fmt_out.i_codec = AOUT_FMT_S16_NE;
+    p_dec->fmt_out.audio.i_bitspersample = 16;
+
+    p_dec->pf_decode_audio = DecodeBlock;
+    p_sys = p_dec->p_sys = malloc (sizeof (*p_sys));
+    if (p_sys == NULL)
+    {
+        free (font_path);
+        return VLC_ENOMEM;
+    }
+
+    p_sys->settings = new_fluid_settings ();
+    p_sys->synth = new_fluid_synth (p_sys->settings);
+    /* FIXME: I bet this is not thread-safe */
+    p_sys->soundfont = fluid_synth_sfload (p_sys->synth, font_path, 1);
+    free (font_path);
+    if (p_sys->soundfont == -1)
+    {
+        msg_Err (p_this, "cannot load sound fonts file");
+        Close (p_this);
+        return VLC_EGENERIC;
+    }
+
+    aout_DateInit (&p_sys->end_date, p_dec->fmt_out.audio.i_rate);
+    aout_DateSet (&p_sys->end_date, 0);
+
+    return VLC_SUCCESS;
+}
+
+
+static void Close (vlc_object_t *p_this)
+{
+    decoder_sys_t *p_sys = ((decoder_t *)p_this)->p_sys;
+
+    if (p_sys->soundfont != -1)
+        fluid_synth_sfunload (p_sys->synth, p_sys->soundfont, 1);
+    delete_fluid_synth (p_sys->synth);
+    delete_fluid_settings (p_sys->settings);
+    free (p_sys);
+}
+
+
+static aout_buffer_t *DecodeBlock (decoder_t *p_dec, block_t **pp_block)
+{
+    block_t *p_block;
+    decoder_sys_t *p_sys = p_dec->p_sys;
+
+    if (pp_block == NULL)
+        return NULL;
+    p_block = *pp_block;
+    if (p_block == NULL)
+        return NULL;
+
+    if (p_block->i_pts && !aout_DateGet (&p_sys->end_date))
+        aout_DateSet (&p_sys->end_date, p_block->i_pts);
+    else
+    if (p_block->i_pts < aout_DateGet (&p_sys->end_date))
+    {
+        msg_Warn (p_dec, "MIDI message in the past?");
+        block_Release (p_block);
+        return NULL;
+    }
+
+    if (p_block->i_buffer < 1)
+        return NULL;
+
+    uint8_t channel = p_block->p_buffer[0] & 0xf;
+    uint8_t p1 = (p_block->i_buffer > 1) ? (p_block->p_buffer[1] & 0x7f) : 0;
+    uint8_t p2 = (p_block->i_buffer > 2) ? (p_block->p_buffer[2] & 0x7f) : 0;
+
+    switch (p_block->p_buffer[0] & 0xf0)
+    {
+        case 0x80:
+            fluid_synth_noteoff (p_sys->synth, channel, p1);
+            break;
+        case 0x90:
+            fluid_synth_noteon (p_sys->synth, channel, p1, p2);
+            break;
+        case 0xB0:
+            fluid_synth_cc (p_sys->synth, channel, p1, p2);
+            break;
+        case 0xC0:
+            fluid_synth_program_change (p_sys->synth, channel, p1);
+            break;
+        case 0xE0:
+            fluid_synth_pitch_bend (p_sys->synth, channel, (p1 << 7) | p2);
+            break;
+    }
+    p_block->p_buffer += p_block->i_buffer;
+    p_block->i_buffer = 0;
+
+    unsigned samples =
+        (p_block->i_pts - aout_DateGet (&p_sys->end_date)) * 441 / 10000;
+    if (samples == 0)
+        return NULL;
+
+    aout_buffer_t *p_out = p_dec->pf_aout_buffer_new (p_dec, samples);
+    if (p_out == NULL)
+    {
+        block_Release (p_block);
+        return NULL;
+    }
+
+    p_out->start_date = aout_DateGet (&p_sys->end_date );
+    p_out->end_date   = aout_DateIncrement (&p_sys->end_date, samples);
+    fluid_synth_write_s16 (p_sys->synth, samples,
+                           (int16_t *)p_out->p_buffer, 0, 2,
+                           (int16_t *)p_out->p_buffer, 1, 2);
+    return p_out;
+}