Solve "unknown format: 3" (#2422)

* Solve execute the following code with return  wav:
iob = io.BytesIO(wav)
wave.open(iob, 'rb')
will throw an "unknown format: 3"  exception

paddlespeech/server/engine/tts/paddleinference/tts_engine.py

@@ -22,7 +22,6 @@ import librosa
 import numpy as np
 import paddle
 import soundfile as sf
-from scipy.io import wavfile
 
 from paddlespeech.cli.log import logger
 from paddlespeech.cli.tts.infer import TTSExecutor
@@ -409,7 +408,8 @@ class PaddleTTSConnectionHandler(TTSServerExecutor):
 
         # wav to base64
         buf = io.BytesIO()
-        wavfile.write(buf, target_fs, wav_speed)
+        sf.write(buf, wav_speed, target_fs, format="wav")
+        buf.seek(0)
         base64_bytes = base64.b64encode(buf.read())
         wav_base64 = base64_bytes.decode('utf-8')
         logger.debug("Audio to string successfully.")

paddlespeech/server/engine/tts/python/tts_engine.py

@@ -20,7 +20,6 @@ import librosa
 import numpy as np
 import paddle
 import soundfile as sf
-from scipy.io import wavfile
 
 from paddlespeech.cli.log import logger
 from paddlespeech.cli.tts.infer import TTSExecutor
@@ -173,7 +172,9 @@ class PaddleTTSConnectionHandler(TTSServerExecutor):
 
         # wav to base64
         buf = io.BytesIO()
-        wavfile.write(buf, target_fs, wav_speed)
+        sf.write(buf, wav_speed, target_fs, format="wav")
+        buf.seek(0)
+
         base64_bytes = base64.b64encode(buf.read())
         wav_base64 = base64_bytes.decode('utf-8')
         logger.debug("Audio to string successfully.")