Render to video using raw image data. Hide GUI.

Hide GUI since it changes window size, breaking the rendering process.

ovgenpy/outputs.py

@@ -2,16 +2,16 @@
 import shlex
 import subprocess
 from abc import ABC, abstractmethod
-from io import BytesIO
-from typing import Optional, TYPE_CHECKING, Type, Callable, TypeVar, List
+from typing import TYPE_CHECKING, Type, List
 
 from dataclasses import dataclass
 
 if TYPE_CHECKING:
+    import numpy as np
     from ovgenpy.ovgenpy import Config
 
 
-IMAGE_FORMAT = 'png'
+RGB_DEPTH = 3
 
 
 class OutputConfig:
@@ -27,9 +27,8 @@ class Output(ABC):
         self.cfg = cfg
 
     @abstractmethod
-    def output_frame_png(self, frame: bytes) -> None:
-        """ Output an encoded PNG file. TODO PNG compression overhead is bad """
-        pass
+    def write_frame(self, frame: 'np.ndarray') -> None:
+        """ Output a Numpy ndarray. """
 
 
 # Glue logic
@@ -49,9 +48,15 @@ FFMPEG = 'ffmpeg'
 FFPLAY = 'ffplay'
 
 
-def ffmpeg_input_video(fps: int) -> List[str]:
-    # Removed: '-c:v {IMAGE_FORMAT}' since it doesn't work
-    return ['-f image2pipe -framerate', str(fps), '-i -']
+assert RGB_DEPTH == 3
+def ffmpeg_input_video(cfg: 'Config') -> List[str]:
+    fps = cfg.fps
+    width = cfg.render.width
+    height = cfg.render.height
+
+    return [f'-f rawvideo -pixel_format rgb24 -video_size {width}x{height}',
+            f'-framerate {fps}',
+            '-i -']
 
 
 def ffmpeg_input_audio(audio_path: str) -> List[str]:
@@ -93,7 +98,7 @@ class FFmpegOutput(Output):
         templates: List[str] = [FFMPEG]
 
         # TODO factor out "get_ffmpeg_input"... what if wrong abstraction?
-        templates += ffmpeg_input_video(fps=ovgen_cfg.fps)  # video
+        templates += ffmpeg_input_video(ovgen_cfg)  # video
         if ovgen_cfg.audio_path:
             templates += ffmpeg_input_audio(audio_path=ovgen_cfg.audio_path)    # audio
 
@@ -113,7 +118,7 @@ class FFmpegOutput(Output):
         # Python documentation discourages accessing popen.stdin. It's wrong.
         # https://stackoverflow.com/a/9886747
 
-    def output_frame_png(self, frame: bytes) -> None:
+    def write_frame(self, frame: bytes) -> None:
         self._stream.write(frame)
 
     def close(self):

ovgenpy/ovgenpy.py

@@ -65,16 +65,13 @@ def main(wave_dir: str, audio_path: Optional[str], fps: int, output: str):
         outputs=[
             outputs.FFmpegOutputConfig(output)
         ],
-        create_window=True
+        create_window=False
     )
 
     ovgen = Ovgen(cfg)
     ovgen.write()
 
 
-COLOR_CHANNELS = 3
-
-
 class Ovgen:
     def __init__(self, cfg: Config):
         self.cfg = cfg
@@ -148,6 +145,8 @@ class Ovgen:
 
             # Output frame
             frame = renderer.get_frame()
+            for output in self.outputs:
+                output.write_frame(frame)
 
             # TODO write to file
             # how to write ndarray to ffmpeg?

ovgenpy/renderer.py

@@ -1,13 +1,16 @@
 from typing import Optional, List, Tuple, TYPE_CHECKING
 
+import matplotlib
 import numpy as np
 from dataclasses import dataclass
+
+from ovgenpy.outputs import RGB_DEPTH
+from ovgenpy.util import ceildiv
+
+matplotlib.use('agg')
 from matplotlib import pyplot as plt
 from matplotlib.backends.backend_agg import FigureCanvasAgg
 
-from ovgenpy.outputs import IMAGE_FORMAT
-from ovgenpy.util import ceildiv
-
 if TYPE_CHECKING:
     from matplotlib.axes import Axes
     from matplotlib.figure import Figure
@@ -167,10 +170,8 @@ class MatplotlibRenderer:
         self.fig.canvas.draw()
         self.fig.canvas.flush_events()
 
-    assert IMAGE_FORMAT == 'png'
-    RGB_DEPTH = 3
-
-    def get_frame(self):
+    def get_frame(self) -> np.ndarray:
+        """ Returns ndarray of shape w,h,3. """
         canvas = self.fig.canvas
 
         # Agg is the default noninteractive backend except on OSX.
@@ -179,12 +180,13 @@ class MatplotlibRenderer:
             raise RuntimeError(
                 f'oh shit, cannot read data from {type(canvas)} != FigureCanvasAgg')
 
-        # buffer_rgba, (w, h) = canvas.print_to_buffer()
+        w = self.cfg.width
+        h = self.cfg.height
+        assert (w, h) == canvas.get_width_height()
 
-        w, h = canvas.get_width_height()
-        buffer_rgb = np.frombuffer(canvas.tostring_rgb(), np.uint8)
-        print(buffer_rgb.shape)
-        np.reshape(buffer_rgb, (w, h, self.RGB_DEPTH))
+        buffer_rgb: np.ndarray = np.frombuffer(canvas.tostring_rgb(), np.uint8)     # TODO Pycharm type inference error
+        np.reshape(buffer_rgb, (w, h, RGB_DEPTH))
+        assert buffer_rgb.size == w * h * RGB_DEPTH
 
         return buffer_rgb
         # # TODO https://matplotlib.org/api/_as_gen/matplotlib.pyplot.imsave.html to