seq_midi_event: fix parsing of missing data bytes

Reorganize the encoder logic to prevent status bytes that appear where
data bytes are expected from being interpreted as data bytes.

diff --git a/src/seq/seq_midi_event.c b/src/seq/seq_midi_event.c
index def9d0e121c9d66e5f6bff09053dc0c0ba62cf33..9c70377e3861a97e725f850a7b0f1634cd9ef976 100644 (file)
--- a/src/seq/seq_midi_event.c
+++ b/src/seq/seq_midi_event.c
@@ -85,32 +85,32 @@ static struct status_event_list_t {
        event_decode_t decode;
 } status_event[] = {
        /* 0x80 - 0xef */
-       {SND_SEQ_EVENT_NOTEOFF,         2, note_event, note_decode},
-       {SND_SEQ_EVENT_NOTEON,          2, note_event, note_decode},
-       {SND_SEQ_EVENT_KEYPRESS,        2, note_event, note_decode},
-       {SND_SEQ_EVENT_CONTROLLER,      2, two_param_ctrl_event, two_param_decode},
-       {SND_SEQ_EVENT_PGMCHANGE,       1, one_param_ctrl_event, one_param_decode},
-       {SND_SEQ_EVENT_CHANPRESS,       1, one_param_ctrl_event, one_param_decode},
-       {SND_SEQ_EVENT_PITCHBEND,       2, pitchbend_ctrl_event, pitchbend_decode},
+       {SND_SEQ_EVENT_NOTEOFF,          2, note_event, note_decode},
+       {SND_SEQ_EVENT_NOTEON,           2, note_event, note_decode},
+       {SND_SEQ_EVENT_KEYPRESS,         2, note_event, note_decode},
+       {SND_SEQ_EVENT_CONTROLLER,       2, two_param_ctrl_event, two_param_decode},
+       {SND_SEQ_EVENT_PGMCHANGE,        1, one_param_ctrl_event, one_param_decode},
+       {SND_SEQ_EVENT_CHANPRESS,        1, one_param_ctrl_event, one_param_decode},
+       {SND_SEQ_EVENT_PITCHBEND,        2, pitchbend_ctrl_event, pitchbend_decode},
        /* invalid */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL},
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL},
        /* 0xf0 - 0xff */
-       {SND_SEQ_EVENT_SYSEX,           1, NULL, NULL}, /* sysex: 0xf0 */
-       {SND_SEQ_EVENT_QFRAME,          1, one_param_event, one_param_decode}, /* 0xf1 */
-       {SND_SEQ_EVENT_SONGPOS,         2, songpos_event, songpos_decode}, /* 0xf2 */
-       {SND_SEQ_EVENT_SONGSEL,         1, one_param_event, one_param_decode}, /* 0xf3 */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL}, /* 0xf4 */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL}, /* 0xf5 */
-       {SND_SEQ_EVENT_TUNE_REQUEST,    0, NULL, NULL}, /* 0xf6 */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL}, /* 0xf7 */
-       {SND_SEQ_EVENT_CLOCK,           0, NULL, NULL}, /* 0xf8 */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL}, /* 0xf9 */
-       {SND_SEQ_EVENT_START,           0, NULL, NULL}, /* 0xfa */
-       {SND_SEQ_EVENT_CONTINUE,        0, NULL, NULL}, /* 0xfb */
-       {SND_SEQ_EVENT_STOP,            0, NULL, NULL}, /* 0xfc */
-       {SND_SEQ_EVENT_NONE,            0, NULL, NULL}, /* 0xfd */
-       {SND_SEQ_EVENT_SENSING,         0, NULL, NULL}, /* 0xfe */
-       {SND_SEQ_EVENT_RESET,           0, NULL, NULL}, /* 0xff */
+       {SND_SEQ_EVENT_SYSEX,            1, NULL, NULL}, /* sysex: 0xf0 */
+       {SND_SEQ_EVENT_QFRAME,           1, one_param_event, one_param_decode}, /* 0xf1 */
+       {SND_SEQ_EVENT_SONGPOS,          2, songpos_event, songpos_decode}, /* 0xf2 */
+       {SND_SEQ_EVENT_SONGSEL,          1, one_param_event, one_param_decode}, /* 0xf3 */
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL}, /* 0xf4 */
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL}, /* 0xf5 */
+       {SND_SEQ_EVENT_TUNE_REQUEST,     0, NULL, NULL}, /* 0xf6 */
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL}, /* 0xf7 */
+       {SND_SEQ_EVENT_CLOCK,            0, NULL, NULL}, /* 0xf8 */
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL}, /* 0xf9 */
+       {SND_SEQ_EVENT_START,            0, NULL, NULL}, /* 0xfa */
+       {SND_SEQ_EVENT_CONTINUE,         0, NULL, NULL}, /* 0xfb */
+       {SND_SEQ_EVENT_STOP,             0, NULL, NULL}, /* 0xfc */
+       {SND_SEQ_EVENT_NONE,            -1, NULL, NULL}, /* 0xfd */
+       {SND_SEQ_EVENT_SENSING,          0, NULL, NULL}, /* 0xfe */
+       {SND_SEQ_EVENT_RESET,            0, NULL, NULL}, /* 0xff */
 };
 
 static int extra_decode_ctrl14(snd_midi_event_t *dev, unsigned char *buf, int len, const snd_seq_event_t *ev);
@@ -311,25 +311,27 @@ int snd_midi_event_encode_byte(snd_midi_event_t *dev, int c, snd_seq_event_t *ev
                return 1;
        }
 
-       if (dev->qlen > 0) {
-               /* rest of command */
-               dev->buf[dev->read++] = c;
-               if (dev->type != ST_SYSEX)
-                       dev->qlen--;
-       } else {
+       if ((c & 0x80) &&
+           (c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {
                /* new command */
+               dev->buf[0] = c;
+               if ((c & 0xf0) == 0xf0) /* system message */
+                       dev->type = (c & 0x0f) + ST_SPECIAL;
+               else
+                       dev->type = (c >> 4) & 0x07;
                dev->read = 1;
-               if (c & 0x80) {
-                       dev->buf[0] = c;
-                       if ((c & 0xf0) == 0xf0) /* special events */
-                               dev->type = (c & 0x0f) + ST_SPECIAL;
-                       else
-                               dev->type = (c >> 4) & 0x07;
-                       dev->qlen = status_event[dev->type].qlen;
-               } else {
-                       /* process this byte as argument */
+               dev->qlen = status_event[dev->type].qlen;
+       } else {
+               if (dev->qlen > 0) {
+                       /* rest of command */
                        dev->buf[dev->read++] = c;
+                       if (dev->type != ST_SYSEX)
+                               dev->qlen--;
+               } else {
+                       /* running status */
+                       dev->buf[1] = c;
                        dev->qlen = status_event[dev->type].qlen - 1;
+                       dev->read = 2;
                }
        }
        if (dev->qlen == 0) {