void main_loop(void) {
const long long int end = ceil(duration * samplerate / 1000.0);
long long int written = 0;
active=1;
short *snd = NULL;
const short smult = rint(pow(10, volume_dbfs/20.0) * 32767.0);
while(active==1 && (duration <= 0 || end >= written)) {
int byteCnt;
for (byteCnt = 0; byteCnt < 10; byteCnt++) {
int i;
ltc_encoder_encode_byte(encoder, byteCnt, 1.0);
const int len = ltc_encoder_get_buffer(encoder, enc_buf);
if (!snd) snd = malloc(len * sizeof(short));
for (i=0;i<len;i++) {
const short val = ( (int)(enc_buf[i] - 128) * smult / 90 );
snd[i] = val;
}
sf_writef_short(sf, snd, len);
written += len;
if (end < written) break;
} /* end byteCnt - one video frames's worth of LTC */
ltc_encoder_inc_timecode(encoder);
}
free(snd);
printf("wrote %lld audio-samples\n", written);
}
void main_loop_reverse(void) {
LTCFrame f;
const long long int end = ceil(duration * samplerate / 1000.0);
long long int written = 0;
active=1;
short *snd = NULL;
const short smult = rint(pow(10, volume_dbfs/20.0) * 32767.0);
while(active==1 && (duration <= 0 || end >= written)) {
int byteCnt;
for (byteCnt = 9; byteCnt >= 0; byteCnt--) {
int i;
ltc_encoder_encode_byte(encoder, byteCnt, -1.0);
const int len = ltc_encoder_get_buffer(encoder, enc_buf);
if (!snd) snd = malloc(len * sizeof(short));
for (i=0;i<len;i++) {
const short val = ( (int)(enc_buf[i] - 128) * smult / 90 );
snd[i] = val;
}
sf_writef_short(sf, snd, len);
written += len;
if (end < written) break;
} /* end byteCnt - one video frames's worth of LTC */
ltc_encoder_get_frame(encoder, &f);
ltc_frame_decrement(&f, ceil(fps_num/fps_den),
fps_num/(double)fps_den == 25.0? LTC_TV_625_50 : LTC_TV_525_60,
LTC_USE_DATE);
ltc_encoder_set_frame(encoder, &f);
}
free(snd);
printf("wrote %lld audio-samples\n", written);
}
int main(int argc, char **argv) {
FILE* file;
double length = 2; // in seconds
double fps = 25;
double sample_rate = 48000;
char *filename;
int vframe_cnt;
int vframe_last;
int total = 0;
ltcsnd_sample_t *buf;
LTCEncoder *encoder;
SMPTETimecode st;
/* start encoding at this timecode */
const char timezone[6] = "+0100";
strcpy(st.timezone, timezone);
st.years = 8;
st.months = 12;
st.days = 31;
st.hours = 23;
st.mins = 59;
st.secs = 59;
st.frame = 0;
/* parse commandline args */
if (argc > 1) {
filename = argv[1];
if (argc > 2) {
sample_rate = atof(argv[2]);
}
if (argc > 3) {
fps = atof(argv[3]);
}
if (argc > 4) {
length = atof(argv[4]);
}
} else {
printf("ltc-encoder - test/example application to encode LTC to a file\n\n");
printf("Usage: ltc-encoder <filename> [sample rate [frame rate [duration in s]]]\n\n");
printf("default-values:\n");
printf(" sample rate: 48000.0 [SPS], frame rate: 25.0 [fps], duration: 2.0 [sec]\n");
printf("Report bugs to Robin Gareus <*****@*****.**>\n");
return 1;
}
/* open output file */
file = fopen(filename, "wb");
if (!file) {
fprintf(stderr, "Error: can not open file '%s' for writing.\n", filename);
return 1;
}
/* prepare encoder */
encoder = ltc_encoder_create(sample_rate, fps,
fps==25?LTC_TV_625_50:LTC_TV_525_60, LTC_USE_DATE);
ltc_encoder_set_timecode(encoder, &st);
#ifdef USE_LOCAL_BUFFER
buf = calloc(ltc_encoder_get_buffersize(encoder), sizeof(ltcsnd_sample_t));
if (!buf) {
return -1;
}
#endif
/* ready to go, print some info first */
printf("sample rate: %.2f\n", sample_rate);
printf("frames/sec: %.2f\n", fps);
printf("secs to write: %.2f\n", length);
printf("sample format: 8bit unsigned mono\n");
vframe_cnt = 0;
vframe_last = length * fps;
while (vframe_cnt++ < vframe_last) {
#if 1 /* encode and write each of the 80 LTC frame bits (10 bytes) */
int byte_cnt;
for (byte_cnt = 0 ; byte_cnt < 10 ; byte_cnt++) {
ltc_encoder_encode_byte(encoder, byte_cnt, 1.0);
#ifdef USE_LOCAL_BUFFER
int len = ltc_encoder_get_buffer(encoder, buf);
#else
int len;
buf = ltc_encoder_get_bufptr(encoder, &len, 1);
#endif
if (len > 0) {
fwrite(buf, sizeof(ltcsnd_sample_t), len, file);
total+=len;
}
}
#else /* encode a complete LTC frame in one step */
ltc_encoder_encode_frame(encoder);
#ifdef USE_LOCAL_BUFFER
int len = ltc_encoder_get_buffer(encoder, buf);
#else
int len;
buf = ltc_encoder_get_bufptr(encoder, &len, 1);
#endif
if (len > 0) {
fwrite(buf, sizeof(ltcsnd_sample_t), len, file);
total+=len;
}
#endif
ltc_encoder_inc_timecode(encoder);
}
fclose(file);
ltc_encoder_free(encoder);
printf("Done: wrote %d samples to '%s'\n", total, filename);
#ifdef USE_LOCAL_BUFFER
free(buf);
#endif
return 0;
}
