move jpeg encoding to turbojpeg

Author: carlodri

picamera2/encoders/jpeg_encoder.py

@@ -1,6 +1,6 @@
 """JPEG encoder functionality"""
 
-import simplejpeg
+import turbojpeg
 
 from picamera2.encoders import Quality
 from picamera2.encoders.multi_encoder import MultiEncoder
@@ -9,12 +9,16 @@
 class JpegEncoder(MultiEncoder):
     """Uses functionality from MultiEncoder"""
 
-    FORMAT_TABLE = {"XBGR8888": "RGBX",
-                    "XRGB8888": "BGRX",
-                    "BGR888": "RGB",
-                    "RGB888": "BGR"}
+    FORMAT_TABLE = {"XBGR8888": turbojpeg.TJPF_RGBX,
+                    "XRGB8888": turbojpeg.TJPF_BGRX,
+                    "BGR888": turbojpeg.TJPF_RGB,
+                    "RGB888": turbojpeg.TJPF_BGR}
+    COLOUR_SUBSAMPLING_TABLE = {"420": turbojpeg.TJSAMP_420,
+                                "422": turbojpeg.TJSAMP_422,
+                                "444": turbojpeg.TJSAMP_444}
 
     def __init__(self, num_threads=4, q=None, colour_space=None, colour_subsampling='420'):
+        self.jpeg = turbojpeg.TurboJPEG()
         """Initialises Jpeg encoder
 
         :param num_threads: Number of threads to use, defaults to 4
@@ -45,8 +49,8 @@ def encode_func(self, request, name):
         if self.colour_space is None:
             self.colour_space = self.FORMAT_TABLE[request.config[name]["format"]]
         array = request.make_array(name)
-        return simplejpeg.encode_jpeg(array, quality=self.q, colorspace=self.colour_space,
-                                      colorsubsampling=self.colour_subsampling)
+        return self.jpeg.encode(array, quality=self.q, colorspace=self.colour_space,
+                                      colorsubsampling=self.COLOUR_SUBSAMPLING_TABLE[self.colour_subsampling])
 
     def _setup(self, quality):
         # If an explicit quality was specified, use it, otherwise try to preserve any q value