/**
* Locates, basing on track->next_event_offset, the next event data in track->buffer,
* interprets it, allocates smf_event_t and fills it properly. Returns smf_event_t
* or NULL, if there was an error. Allocating event means adding it to the track;
* see smf_event_new().
*/
static smf_event_t *
parse_next_event(smf_track_t *track)
{
uint32_t etime = 0;
uint32_t len;
size_t buffer_length;
unsigned char *c, *start;
smf_event_t *event = smf_event_new();
if (event == NULL)
goto error;
c = start = (unsigned char *)track->file_buffer + track->next_event_offset;
assert(track->file_buffer != NULL);
assert(track->file_buffer_length > 0);
assert(track->next_event_offset > 0);
buffer_length = track->file_buffer_length - track->next_event_offset;
/* if there was no meta-EOT event, buffer_length can be zero. This is
an error in the SMF file, but it shouldn't be treated as fatal.
*/
if (buffer_length == 0) {
g_warning ("SMF warning: expected EOT at end of track, but none found");
goto error;
}
/* First, extract time offset from previous event. */
if (smf_extract_vlq(c, buffer_length, &etime, &len)) {
goto error;
}
c += len;
buffer_length -= len;
if (buffer_length <= 0)
goto error;
/* Now, extract the actual event. */
if (extract_midi_event(c, buffer_length, event, &len, track->last_status)) {
goto error;
}
c += len;
buffer_length -= len;
track->last_status = event->midi_buffer[0];
track->next_event_offset += c - start;
smf_track_add_event_delta_pulses(track, event, etime);
return (event);
error:
if (event != NULL)
smf_event_delete(event);
return (NULL);
}
/**
* Allocates an smf_event_t structure and fills it with "len" bytes copied
* from "midi_data".
* \param midi_data Pointer to MIDI data. It sill be copied to the newly allocated event->midi_buffer.
* \param len Length of the buffer. It must be proper MIDI event length, e.g. 3 for Note On event.
* \return Event containing MIDI data or NULL.
*/
smf_event_t *
smf_event_new_from_pointer(void *midi_data, int len)
{
smf_event_t *event;
event = smf_event_new();
if (event == NULL)
return (NULL);
event->midi_buffer_length = len;
event->midi_buffer = malloc(event->midi_buffer_length);
if (event->midi_buffer == NULL) {
g_critical("Cannot allocate MIDI buffer structure: %s", strerror(errno));
smf_event_delete(event);
return (NULL);
}
memcpy(event->midi_buffer, midi_data, len);
return (event);
}
static int
cmd_eventadd(char *str)
{
int midi_buffer_length;
double seconds;
unsigned char *midi_buffer;
char *time, *endtime;
if (selected_track == NULL) {
g_critical("Please select a track first, using 'track <number>' command.");
return (-1);
}
if (str == NULL) {
eventadd_usage();
return (-2);
}
/* Extract the time. Don't use strsep(3), it doesn't work on SunOS. */
time = str;
str = strchr(str, ' ');
if (str != NULL) {
*str = '\0';
str++;
}
seconds = strtod(time, &endtime);
if (endtime - time != strlen(time)) {
g_critical("Time is supposed to be a number, without trailing characters.");
return (-3);
}
/* Called with one parameter? */
if (str == NULL) {
eventadd_usage();
return (-4);
}
if (decode_hex(str, &midi_buffer, &midi_buffer_length)) {
eventadd_usage();
return (-5);
}
selected_event = smf_event_new();
if (selected_event == NULL) {
g_critical("smf_event_new() failed, event not created.");
return (-6);
}
selected_event->midi_buffer = midi_buffer;
selected_event->midi_buffer_length = midi_buffer_length;
if (smf_event_is_valid(selected_event) == 0) {
g_critical("Event is invalid from the MIDI specification point of view, not created.");
smf_event_delete(selected_event);
selected_event = NULL;
return (-7);
}
smf_track_add_event_seconds(selected_track, selected_event, seconds);
g_message("Event created.");
return (0);
}
/**
* Allocates an smf_event_t structure and fills it with at most three bytes of data.
* For example, if you need to create Note On event, do something like this:
*
* smf_event_new_from_bytes(0x90, 0x3C, 0x7f);
*
* To create event for MIDI message that is shorter than three bytes, do something
* like this:
*
* smf_event_new_from_bytes(0xC0, 0x42, -1);
*
* \param first_byte First byte of MIDI message. Must be valid status byte.
* \param second_byte Second byte of MIDI message or -1, if message is one byte long.
* \param third_byte Third byte of MIDI message or -1, if message is two bytes long.
* \return Event containing MIDI data or NULL.
*/
smf_event_t *
smf_event_new_from_bytes(int first_byte, int second_byte, int third_byte)
{
int len;
smf_event_t *event;
event = smf_event_new();
if (event == NULL)
return (NULL);
if (first_byte < 0) {
g_critical("First byte of MIDI message cannot be < 0");
smf_event_delete(event);
return (NULL);
}
if (first_byte > 255) {
g_critical("smf_event_new_from_bytes: first byte is %d, which is larger than 255.", first_byte);
return (NULL);
}
if (!is_status_byte(first_byte)) {
g_critical("smf_event_new_from_bytes: first byte is not a valid status byte.");
return (NULL);
}
if (second_byte < 0)
len = 1;
else if (third_byte < 0)
len = 2;
else
len = 3;
if (len > 1) {
if (second_byte > 255) {
g_critical("smf_event_new_from_bytes: second byte is %d, which is larger than 255.", second_byte);
return (NULL);
}
if (is_status_byte(second_byte)) {
g_critical("smf_event_new_from_bytes: second byte cannot be a status byte.");
return (NULL);
}
}
if (len > 2) {
if (third_byte > 255) {
g_critical("smf_event_new_from_bytes: third byte is %d, which is larger than 255.", third_byte);
return (NULL);
}
if (is_status_byte(third_byte)) {
g_critical("smf_event_new_from_bytes: third byte cannot be a status byte.");
return (NULL);
}
}
event->midi_buffer_length = len;
event->midi_buffer = malloc(event->midi_buffer_length);
if (event->midi_buffer == NULL) {
g_critical("Cannot allocate MIDI buffer structure: %s", strerror(errno));
smf_event_delete(event);
return (NULL);
}
event->midi_buffer[0] = first_byte;
if (len > 1)
event->midi_buffer[1] = second_byte;
if (len > 2)
event->midi_buffer[2] = third_byte;
return (event);
}