SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_bert_shutdown);
SWITCH_MODULE_DEFINITION(mod_bert, mod_bert_load, mod_bert_shutdown, NULL);
-static int16_t bert_next_sample(int16_t sample, uint8_t *going_up)
-{
- if (sample == INT16_MAX || !(*going_up)) {
- *going_up = 0;
- return --sample;
- }
- if (sample == INT16_MIN || *going_up) {
- *going_up = 1;
- return ++sample;
- }
- switch_assert(0);
-}
+/* http://en.wikipedia.org/wiki/Digital_milliwatt */
+unsigned char ulaw_digital_milliwatt[8] = { 0x1e, 0x0b, 0x0b, 0x1e, 0x9e, 0x8b, 0x8b, 0x9e };
+
+typedef struct {
+ uint32_t processed_samples;
+ uint32_t err_samples;
+ uint32_t window_ms;
+ uint32_t window_samples;
+ uint8_t sequence_sample;
+ uint8_t predicted_sample;
+ float max_err;
+ float max_err_hit;
+ float max_err_ever;
+ uint8_t in_sync;
+ uint8_t hangup_on_error;
+ uint8_t milliwatt_index;
+ uint8_t milliwatt_prediction_index;
+ switch_time_t timeout;
+ FILE *input_debug_f;
+ FILE *output_debug_f;
+} bert_t;
+
+#define bert_increase_milliwatt_index(index) \
+ do { \
+ if ((index) == (switch_arraylen(ulaw_digital_milliwatt)-1)) { \
+ (index) = 0; \
+ } else { \
+ (index) = ((index) + 1); \
+ } \
+ } while (0);
#define BERT_DEFAULT_WINDOW_MS 1000
#define BERT_DEFAULT_MAX_ERR 10.0
const char *var = NULL;
int i = 0;
int synced = 0;
- uint32_t ts = 0;
+ uint32_t write_ts = 0;
int32_t timeout_ms = 0;
- struct {
- uint32_t processed_samples;
- uint32_t err_samples;
- uint32_t window_ms;
- uint32_t window_samples;
- int16_t sequence_sample;
- int16_t predicted_sample;
- int16_t previous_sample;
- float max_err;
- float max_err_hit;
- float max_err_ever;
- uint8_t in_sync;
- uint8_t hangup_on_error;
- uint8_t sequence_going_up;
- uint8_t prediction_going_up;
- switch_time_t timeout;
- } bert;
+ bert_t bert = { 0 };
+
+ memset(&bert, 0, sizeof(bert));
channel = switch_core_session_get_channel(session);
switch_core_session_get_read_impl(session, &read_impl);
- memset(&bert, 0, sizeof(bert));
+ if (read_impl.ianacode != 0) {
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "This application only works when using ulaw codec\n");
+ goto done;
+ }
+
bert.window_ms = BERT_DEFAULT_WINDOW_MS;
bert.window_samples = switch_samples_per_packet(read_impl.samples_per_second, bert.window_ms);
bert.max_err = BERT_DEFAULT_MAX_ERR;
- bert.sequence_going_up = 1;
timeout_ms = BERT_DEFAULT_TIMEOUT_MS;
/* check if there are user-defined overrides */
bert.hangup_on_error = 1;
}
}
+ if ((var = switch_channel_get_variable(channel, "bert_debug_io_file"))) {
+ char debug_file[1024];
+ snprintf(debug_file, sizeof(debug_file), "%s.in", var);
+ bert.input_debug_f = fopen(debug_file, "w");
+ if (!bert.input_debug_f) {
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to open input debug file %s\n", debug_file);
+ }
+ snprintf(debug_file, sizeof(debug_file), "%s.out", var);
+ bert.output_debug_f = fopen(debug_file, "w");
+ if (!bert.output_debug_f) {
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to open output debug file %s\n", debug_file);
+ }
+ }
bert.timeout = (switch_micro_time_now() + (timeout_ms * 1000));
write_frame.data = switch_core_session_alloc(session, SWITCH_RECOMMENDED_BUFFER_SIZE);
write_frame.buflen = SWITCH_RECOMMENDED_BUFFER_SIZE;
- switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "BERT Test Window=%ums/%u MaxErr=%f%%\n", bert.window_ms, bert.window_samples, bert.max_err);
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "BERT Test Window=%ums/%u, MaxErr=%f%%, Timeout=%dms\n", bert.window_ms, bert.window_samples, bert.max_err, timeout_ms);
if (bert.window_samples <= 0) {
switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to compute BERT window samples!\n");
goto done;
}
while (switch_channel_ready(channel)) {
- int16_t *read_samples = NULL;
- int16_t *write_samples = NULL;
+ uint8_t *read_samples = NULL;
+ uint8_t *write_samples = NULL;
+
status = switch_core_session_read_frame(session, &read_frame, SWITCH_IO_FLAG_NONE, 0);
if (!SWITCH_READ_ACCEPTABLE(status)) {
break;
}
- /* BERT Sync */
+
+ if (bert.timeout && !synced) {
+ switch_time_t now = switch_micro_time_now();
+ if (now >= bert.timeout) {
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_WARNING, "BERT Timeout (read_samples=%d, read_bytes=%d, expected_samples=%d, %s)\n",
+ read_frame->samples, read_frame->datalen, read_impl.samples_per_packet, switch_core_session_get_uuid(session));
+ if (bert.hangup_on_error) {
+ switch_channel_hangup(channel, SWITCH_CAUSE_MEDIA_TIMEOUT);
+ }
+ }
+ }
+
+ if (!read_frame->datalen) {
+ continue;
+ }
+
+ if (read_frame->samples != read_impl.samples_per_packet) {
+ switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "Only read %d samples, expected %d!\n", read_frame->samples, read_impl.samples_per_packet);
+ continue;
+ }
+
read_samples = read_frame->data;
write_samples = write_frame.data;
- for (i = 0; i < (read_frame->datalen / 2); i++) {
+ if (read_frame->samples) {
+ if (bert.input_debug_f) {
+ fwrite(read_frame->data, read_frame->datalen, 1, bert.input_debug_f);
+ }
+ }
+
+ /* BERT Sync Loop */
+ for (i = 0; i < read_frame->samples; i++) {
if (bert.window_samples == bert.processed_samples) {
/* Calculate error rate */
float err = ((float)((float)bert.err_samples / (float)bert.processed_samples) * 100.0);
}
bert.processed_samples = 0;
bert.err_samples = 0;
- if (bert.timeout && !synced) {
- switch_time_t now = switch_micro_time_now();
- if (now >= bert.timeout) {
- switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_WARNING, "BERT Timeout\n");
- if (bert.hangup_on_error) {
- switch_channel_hangup(channel, SWITCH_CAUSE_MEDIA_TIMEOUT);
- }
- }
- }
}
+
if (bert.predicted_sample != read_samples[i]) {
bert.err_samples++;
+ if (!bert.in_sync) {
+ /* If we're not in sync, we must reset the index on error to start the pattern detection again */
+ bert.milliwatt_prediction_index = 0;
+ }
}
- if (bert.previous_sample > read_samples[i]) {
- bert.prediction_going_up = 0;
- } else {
- bert.prediction_going_up = 1;
- }
- bert.predicted_sample = bert_next_sample(read_samples[i], &bert.prediction_going_up);
- bert.sequence_sample = bert_next_sample(bert.sequence_sample, &bert.sequence_going_up);
+
+ /* Calculate our next sequence sample to write */
+ bert.sequence_sample = ulaw_digital_milliwatt[bert.milliwatt_index];
+ //switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "[%d] 0x%X\n", bert.milliwatt_index, bert.sequence_sample);
+ bert_increase_milliwatt_index(bert.milliwatt_index);
+ //switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "[%d] 0x%X\n", bert.milliwatt_index, bert.sequence_sample);
write_samples[i] = bert.sequence_sample;
- bert.previous_sample = read_samples[i];
+
+ /* Try to guess what the next sample will be in the milliwatt sequence */
+ bert.predicted_sample = ulaw_digital_milliwatt[bert.milliwatt_prediction_index];
+ bert_increase_milliwatt_index(bert.milliwatt_prediction_index);
+
bert.processed_samples++;
}
write_frame.datalen = read_frame->datalen;
write_frame.samples = i;
- write_frame.timestamp = ts;
+ write_frame.timestamp = write_ts;
+ if (bert.output_debug_f) {
+ fwrite(write_frame.data, write_frame.datalen, 1, bert.output_debug_f);
+ }
status = switch_core_session_write_frame(session, &write_frame, SWITCH_IO_FLAG_NONE, 0);
if (!SWITCH_READ_ACCEPTABLE(status)) {
break;
}
- ts += read_impl.samples_per_packet;
+
+ write_ts += read_impl.samples_per_packet;
}
done:
+ if (bert.input_debug_f) {
+ fclose(bert.input_debug_f);
+ }
+ if (bert.output_debug_f) {
+ fclose(bert.output_debug_f);
+ }
switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "BERT Test Completed. MaxErr=%f%%\n", synced ? bert.max_err_hit : bert.max_err_ever);
-
}
SWITCH_MODULE_LOAD_FUNCTION(mod_bert_load)