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Mindwerks · Jan 6, 2021 · 692e48a · 692e48a
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commit 692e48a
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diff --git a/src/f_mus.c b/src/f_mus.c
@@ -163,6 +163,9 @@ _WM_ParseNewMus(uint8_t *mus_data, uint32_t mus_size) {
                     mus_event[0] = 0x90 | (mus_data[mus_data_ofs] & 0x0f);
                     mus_event[1] = mus_data[mus_data_ofs + 1] & 0x7f;
                     mus_event[2] = mus_data[mus_data_ofs + 2];
+                    // The maximum volume is 127, but it is encoded as a byte. Some songs
+                    // erroneously use values higher than 127, so we have to clamp them down.
+                    // https://github.com/Mindwerks/wildmidi/pull/226
                     if (mus_event[2] > 0x7f) mus_event[2] = 0x7f;
                     mus_event[3] = 0;
                     mus_prev_vol[mus_data[mus_data_ofs] & 0x0f] = mus_event[2];
@@ -260,6 +263,9 @@ _WM_ParseNewMus(uint8_t *mus_data, uint32_t mus_size) {
                         mus_event[0] = 0xb0 | (mus_data[mus_data_ofs] & 0x0f);
                         mus_event[1] = 7;
                         mus_event[2] = mus_data[mus_data_ofs + 2];
+                        // The maximum volume is 127, but it is encoded as a byte. Some songs
+                        // erroneously use values higher than 127, so we have to clamp them down.
+                        // https://github.com/Mindwerks/wildmidi/pull/226
                         if (mus_event[2] > 0x7f) mus_event[2] = 0x7f;
                         mus_event[3] = 0;
                         break;

diff --git a/src/mus2mid.c b/src/mus2mid.c
@@ -353,6 +353,9 @@ int _WM_mus2midi(const uint8_t *in, uint32_t insize,
                 bit1 = *cur & 127;
                 if (*cur++ & 128) {   /* volume bit? */
                     channel_volume[channelMap[channel]] = *cur++;
+                    /* The maximum volume is 127, but it is encoded as a byte. Some songs
+                       erroneously use values higher than 127, so we have to clamp them down.
+                       https://github.com/Mindwerks/wildmidi/pull/226 */
                     if (channel_volume[channelMap[channel]] > 127) channel_volume[channelMap[channel]] = 127;
                 }
                 bit2 = channel_volume[channelMap[channel]];
@@ -388,6 +391,9 @@ int _WM_mus2midi(const uint8_t *in, uint32_t insize,
                     }
                     bit1 = midimap[*cur++];
                     bit2 = *cur++;
+                    /* The maximum volume is 127, but it is encoded as a byte. Some songs
+                       erroneously use values higher than 127, so we have to clamp them down.
+                       https://github.com/Mindwerks/wildmidi/pull/226 */
                     if (bit1 == 0x07 && bit2 > 127) bit2 = 127;
                 }
                 break;