FS-4527 --resolve add resample core support for asr. This code is very isolated and only effects mod_unimrcp at this time.

src/include/switch_module_interfaces.h

@@ -408,6 +408,14 @@ struct switch_asr_handle {
 	char *param;
 	/*! the handle's memory pool */
 	switch_memory_pool_t *memory_pool;
+	switch_buffer_t *buffer;
+	switch_byte_t *dbuf;
+	switch_size_t dbuflen;
+	switch_audio_resampler_t *resampler;
+	/*! the current samplerate */
+	uint32_t samplerate;
+	/*! the current native samplerate */
+	uint32_t native_rate;
 	/*! private data for the format module to store handle specific info */
 	void *private_info;
 };

src/mod/asr_tts/mod_unimrcp/mod_unimrcp.c

@@ -339,6 +339,7 @@ struct speech_channel {
 	switch_hash_t *params;
 	/** app specific data */
 	void *data;
+	void *fsh;
 };
 typedef struct speech_channel speech_channel_t;
 
@@ -1591,6 +1592,7 @@ static switch_status_t synth_speech_open(switch_speech_handle_t *sh, const char
 		goto done;
 	}
 	sh->private_info = schannel;
+	schannel->fsh = sh;
 
 	/* Open the channel */
 	if (zstr(profile_name)) {
@@ -1835,7 +1837,16 @@ static apt_bool_t speech_on_channel_add(mrcp_application_t *application, mrcp_se
 	if (!descriptor) {
 		goto error;
 	}
+
 	schannel->rate = descriptor->sampling_rate;
+
+	/* report negotiated sample rate back to FreeSWITCH */
+	if (schannel->type == SPEECH_CHANNEL_SYNTHESIZER) {
+		((switch_speech_handle_t*)schannel->fsh)->native_rate = schannel->rate;
+	} else {
+		((switch_asr_handle_t*)schannel->fsh)->native_rate = schannel->rate;
+	}
+
 	if (descriptor->name.length) {
 		strncpy(codec_name, descriptor->name.buf, sizeof(codec_name));
 	}
@@ -2914,6 +2925,7 @@ static switch_status_t recog_asr_open(switch_asr_handle_t *ah, const char *codec
 		status = SWITCH_STATUS_FALSE;
 		goto done;
 	}
+	schannel->fsh = ah;
 	ah->private_info = schannel;
 	r = (recognizer_data_t *) switch_core_alloc(ah->memory_pool, sizeof(recognizer_data_t));
 	schannel->data = r;

src/switch_core_asr.c

@@ -77,6 +77,8 @@ SWITCH_DECLARE(switch_status_t) switch_core_asr_open(switch_asr_handle_t *ah,
 	}
 	ah->rate = rate;
 	ah->name = switch_core_strdup(ah->memory_pool, module_name);
+	ah->samplerate = rate;
+	ah->native_rate = rate;
 
 	status = ah->asr_interface->asr_open(ah, codec, rate, dest, flags);
 
@@ -223,6 +225,8 @@ SWITCH_DECLARE(switch_status_t) switch_core_asr_close(switch_asr_handle_t *ah, s
 	status = ah->asr_interface->asr_close(ah, flags);
 	switch_set_flag(ah, SWITCH_ASR_FLAG_CLOSED);
 
+	switch_resample_destroy(&ah->resampler);
+
 	UNPROTECT_INTERFACE(ah->asr_interface);
 
 	if (switch_test_flag(ah, SWITCH_ASR_FLAG_FREE_POOL)) {
@@ -234,8 +238,37 @@ SWITCH_DECLARE(switch_status_t) switch_core_asr_close(switch_asr_handle_t *ah, s
 
 SWITCH_DECLARE(switch_status_t) switch_core_asr_feed(switch_asr_handle_t *ah, void *data, unsigned int len, switch_asr_flag_t *flags)
 {
+	switch_size_t orig_len = len;
 	switch_assert(ah != NULL);
 
+	if (ah->native_rate && ah->samplerate && ah->native_rate != ah->samplerate) {
+		if (!ah->resampler) {
+			if (switch_resample_create(&ah->resampler,
+									   ah->samplerate, ah->native_rate, (uint32_t) orig_len, SWITCH_RESAMPLE_QUALITY, 1) != SWITCH_STATUS_SUCCESS) {
+				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Unable to create resampler!\n");
+				return SWITCH_STATUS_GENERR;
+			}
+		}
+
+		switch_resample_process(ah->resampler, data, len / 2);
+		if (ah->resampler->to_len > orig_len) {
+			if (!ah->dbuf) {
+				void *mem;
+				ah->dbuflen = ah->resampler->to_len * 2;
+				mem = realloc(ah->dbuf, ah->dbuflen);
+				switch_assert(mem);
+				ah->dbuf = mem;
+			}
+			switch_assert(ah->resampler->to_len * 2 <= ah->dbuflen);
+			memcpy(ah->dbuf, ah->resampler->to, ah->resampler->to_len * 2);
+			data = ah->dbuf;
+		} else {
+			memcpy(data, ah->resampler->to, ah->resampler->to_len * 2);
+		}
+
+		len = ah->resampler->to_len;
+	}
+
 	return ah->asr_interface->asr_feed(ah, data, len, flags);
 }