diff --git a/whispercpp.pxd b/whispercpp.pxd
index 9381078..1a033db 100644
--- a/whispercpp.pxd
+++ b/whispercpp.pxd
@@ -1,9 +1,8 @@
 #!python
 # cython: language_level=3
-
 from libc.stdint cimport int64_t
 
-cdef:
+cdef nogil:
     int WHISPER_SAMPLE_RATE = 16000
     int WHISPER_N_FFT = 400
     int WHISPER_N_MEL = 80
@@ -13,6 +12,9 @@ cdef:
     char* TEST_FILE = b'test.wav'
     char* DEFAULT_MODEL = b'ggml-tiny.bin'
     char* LANGUAGE = b'fr'
+    ctypedef struct audio_data:
+        float* frames;
+        int n_frames;
 
 cdef extern from "whisper.h" nogil:
     enum whisper_sampling_strategy:
@@ -109,8 +111,3 @@ cdef extern from "whisper.h" nogil:
     const char* whisper_print_system_info()
     const char* whisper_full_get_segment_text(whisper_context*, int)
 
-
-ctypedef struct audio_data:
-    float* frames;
-    int n_frames;
-
diff --git a/whispercpp.pyx b/whispercpp.pyx
index 2737063..187c177 100644
--- a/whispercpp.pyx
+++ b/whispercpp.pyx
@@ -8,12 +8,14 @@ import numpy as np
 import requests
 import os
 
+
 cimport numpy as cnp
 
 cdef int SAMPLE_RATE = 16000
-cdef char* TEST_FILE = b'test.wav'
+cdef char* TEST_FILE = 'test.wav'
 cdef char* DEFAULT_MODEL = 'tiny'
 cdef char* LANGUAGE = b'fr'
+cdef int N_THREADS = os.cpu_count()
 
 MODELS = {
     'model_ggml_tiny.bin': 'https://ggml.ggerganov.com/ggml-model-whisper-tiny.bin',
@@ -67,7 +69,7 @@ cdef audio_data load_audio(bytes file, int sr = SAMPLE_RATE):
 
     return data
 
-cdef whisper_full_params default_params():
+cdef whisper_full_params default_params() nogil:
     cdef whisper_full_params params = whisper_full_default_params(
         whisper_sampling_strategy.WHISPER_SAMPLING_GREEDY
     )
@@ -75,6 +77,7 @@ cdef whisper_full_params default_params():
     params.print_progress = True
     params.translate = False
     params.language = <const char *> LANGUAGE
+    n_threads = N_THREADS
     return params
 
 
@@ -83,25 +86,26 @@ cdef class Whisper:
     cdef whisper_full_params params
 
     def __init__(self, model=DEFAULT_MODEL, pb=None):
-        model_fullname = f'model_ggml_{model.decode()}.bin'.encode('utf8')
+        model_fullname = f'model_ggml_{model}.bin'.encode('utf8')
         download_model(model_fullname)
         cdef bytes model_b = model_fullname
         self.ctx = whisper_init(model_b)
         self.params = default_params()
+        whisper_print_system_info()
 
     def __dealloc__(self):
         whisper_free(self.ctx)
 
-    def transcribe(self):
-        cdef audio_data data = load_audio(TEST_FILE) 
+    def transcribe(self, filename=TEST_FILE):
+        cdef audio_data data = load_audio(<bytes>filename)
         return whisper_full(self.ctx, self.params, data.frames, data.n_frames)
     
-    cpdef str extract_text(self, int res):
+    cpdef list extract_text(self, int res):
         if res != 0:
             raise RuntimeError
         cdef int n_segments = whisper_full_n_segments(self.ctx)
-        return b'\n'.join([
-            whisper_full_get_segment_text(self.ctx, i) for i in range(n_segments)
-        ]).decode()
+        return [
+            whisper_full_get_segment_text(self.ctx, i).decode() for i in range(n_segments)
+        ]