# Copyright 2022 Lunar Ring. All rights reserved. # Written by Johannes Stelzer, email stelzer@lunar-ring.ai twitter @j_stelzer # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import subprocess import os import numpy as np from tqdm import tqdm import cv2 from typing import List import ffmpeg # pip install ffmpeg-python. if error with broken pipe: conda update ffmpeg class MovieSaver(): def __init__( self, fp_out: str, fps: int = 24, shape_hw: List[int] = None, crf: int = 24, codec: str = 'libx264', preset: str = 'fast', pix_fmt: str = 'yuv420p', silent_ffmpeg: bool = True): r""" Initializes movie saver class - a human friendly ffmpeg wrapper. After you init the class, you can dump numpy arrays x into moviesaver.write_frame(x). Don't forget toi finalize movie file with moviesaver.finalize(). Args: fp_out: str Output file name. If it already exists, it will be deleted. fps: int Frames per second. shape_hw: List[int, int] Output shape, optional argument. Can be initialized automatically when first frame is written. crf: int ffmpeg doc: the range of the CRF scale is 0–51, where 0 is lossless (for 8 bit only, for 10 bit use -qp 0), 23 is the default, and 51 is worst quality possible. A lower value generally leads to higher quality, and a subjectively sane range is 17–28. Consider 17 or 18 to be visually lossless or nearly so; it should look the same or nearly the same as the input but it isn't technically lossless. The range is exponential, so increasing the CRF value +6 results in roughly half the bitrate / file size, while -6 leads to roughly twice the bitrate. codec: int Number of diffusion steps. Larger values will take more compute time. preset: str Choose between ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow. ffmpeg doc: A preset is a collection of options that will provide a certain encoding speed to compression ratio. A slower preset will provide better compression (compression is quality per filesize). This means that, for example, if you target a certain file size or constant bit rate, you will achieve better quality with a slower preset. Similarly, for constant quality encoding, you will simply save bitrate by choosing a slower preset. pix_fmt: str Pixel format. Run 'ffmpeg -pix_fmts' in your shell to see all options. silent_ffmpeg: bool Surpress the output from ffmpeg. """ if len(os.path.split(fp_out)[0]) > 0: assert os.path.isdir(os.path.split(fp_out)[0]), "Directory does not exist!" self.fp_out = fp_out self.fps = fps self.crf = crf self.pix_fmt = pix_fmt self.codec = codec self.preset = preset self.silent_ffmpeg = silent_ffmpeg if os.path.isfile(fp_out): os.remove(fp_out) self.init_done = False self.nmb_frames = 0 if shape_hw is None: self.shape_hw = [-1, 1] else: if len(shape_hw) == 2: shape_hw.append(3) self.shape_hw = shape_hw self.initialize() print(f"MovieSaver initialized. fps={fps} crf={crf} pix_fmt={pix_fmt} codec={codec} preset={preset}") def initialize(self): args = ( ffmpeg .input('pipe:', format='rawvideo', pix_fmt='rgb24', s='{}x{}'.format(self.shape_hw[1], self.shape_hw[0]), framerate=self.fps) .output(self.fp_out, crf=self.crf, pix_fmt=self.pix_fmt, c=self.codec, preset=self.preset) .overwrite_output() .compile() ) if self.silent_ffmpeg: self.ffmpg_process = subprocess.Popen(args, stdin=subprocess.PIPE, stderr=subprocess.DEVNULL, stdout=subprocess.DEVNULL) else: self.ffmpg_process = subprocess.Popen(args, stdin=subprocess.PIPE) self.init_done = True self.shape_hw = tuple(self.shape_hw) print(f"Initialization done. Movie shape: {self.shape_hw}") def write_frame(self, out_frame: np.ndarray): r""" Function to dump a numpy array as frame of a movie. Args: out_frame: np.ndarray Numpy array, in np.uint8 format. Convert with np.astype(x, np.uint8). Dim 0: y Dim 1: x Dim 2: RGB """ assert out_frame.dtype == np.uint8, "Convert to np.uint8 before" assert len(out_frame.shape) == 3, "out_frame needs to be three dimensional, Y X C" assert out_frame.shape[2] == 3, f"need three color channels, but you provided {out_frame.shape[2]}." if not self.init_done: self.shape_hw = out_frame.shape self.initialize() assert self.shape_hw == out_frame.shape, f"You cannot change the image size after init. Initialized with {self.shape_hw}, out_frame {out_frame.shape}" # write frame self.ffmpg_process.stdin.write( out_frame .astype(np.uint8) .tobytes() ) self.nmb_frames += 1 def finalize(self): r""" Call this function to finalize the movie. If you forget to call it your movie will be garbage. """ if self.nmb_frames == 0: print("You did not write any frames yet! nmb_frames = 0. Cannot save.") return self.ffmpg_process.stdin.close() self.ffmpg_process.wait() duration = int(self.nmb_frames / self.fps) print(f"Movie saved, {duration}s playtime, watch here: \n{self.fp_out}") def concatenate_movies(fp_final: str, list_fp_movies: List[str]): r""" Concatenate multiple movie segments into one long movie, using ffmpeg. Parameters ---------- fp_final : str Full path of the final movie file. Should end with .mp4 list_fp_movies : list[str] List of full paths of movie segments. """ assert fp_final[-4] == ".", "fp_final seems to miss file extension: {fp_final}" for fp in list_fp_movies: assert os.path.isfile(fp), f"Input movie does not exist: {fp}" assert os.path.getsize(fp) > 100, f"Input movie seems empty: {fp}" if os.path.isfile(fp_final): os.remove(fp_final) # make a list for ffmpeg list_concat = [] for fp_part in list_fp_movies: list_concat.append(f"""file '{fp_part}'""") # save this list fp_list = "tmp_move.txt" with open(fp_list, "w") as fa: for item in list_concat: fa.write("%s\n" % item) cmd = f'ffmpeg -f concat -safe 0 -i {fp_list} -c copy {fp_final}' subprocess.call(cmd, shell=True) os.remove(fp_list) if os.path.isfile(fp_final): print(f"concatenate_movies: success! Watch here: {fp_final}") class MovieReader(): r""" Class to read in a movie. """ def __init__(self, fp_movie): self.video_player_object = cv2.VideoCapture(fp_movie) self.nmb_frames = int(self.video_player_object.get(cv2.CAP_PROP_FRAME_COUNT)) self.fps_movie = int(self.video_player_object.get(cv2.CAP_PROP_FPS)) self.shape = [100, 100, 3] self.shape_is_set = False def get_next_frame(self): success, image = self.video_player_object.read() if success: if not self.shape_is_set: self.shape_is_set = True self.shape = image.shape return image else: return np.zeros(self.shape) if __name__ == "__main__": fps = 2 list_fp_movies = [] for k in range(4): fp_movie = f"/tmp/my_random_movie_{k}.mp4" list_fp_movies.append(fp_movie) ms = MovieSaver(fp_movie, fps=fps) for fn in tqdm(range(30)): img = (np.random.rand(512, 1024, 3) * 255).astype(np.uint8) ms.write_frame(img) ms.finalize() fp_final = "/tmp/my_concatenated_movie.mp4" concatenate_movies(fp_final, list_fp_movies)