#!/usr/bin/env python3

"""h264ify - Upgrade my videos to h.264/AAC for Chromecast.

With Google Chrome, you can Chromecast any movie file from your PC by dragging
the movie into a Chrome window, and then cast the tab to your Chromecast.

However this only works if the video is encoded with H.264 for video and
AAC for audio. Other video files will instead "download" in Chrome instead of
play inside the tab.

This script takes input video file names (without a `.mp4` extension), and
encodes them into a file of the same name but with a `.mp4` extension.

Usage: h264ify <video files...>

--Kirsle
"""

import os
import subprocess
import sys

def main():
    if len(sys.argv) < 2:
        print("Usage: {} <video files...>".format(sys.argv[0]))
        sys.exit(1)

    for input_file in sys.argv[1:]:
        # Dissect the file parts.
        file_parts = os.path.basename(input_file).split(".")
        extension  = file_parts.pop().lower()
        basename   = ".".join(file_parts)

        # Common video file types.
        if extension not in [
                "avi", "mov", "mpv", "mkv", "mp4", "mpg", "mpeg", "flv",
            ]:
            continue

        # Sanity check that they didn't give a .mp4 file.
        if extension == "mp4":
            print("The file extension '.mp4' might mean the video already works with the Chromecast")

            # If there were many files to run on, don't stop and prompt them,
            # just warn and skip it.
            if len(sys.argv) == 2 and not input("Are you sure you want to encode it anyway? [yN] ").strip().lower().startswith("y"):
                print("Exiting")
                sys.exit(1)
            elif len(sys.argv) == 2:
                continue

        # Make the output file name.
        output_file = basename + ".mp4"
        i = 0
        while os.path.isfile(output_file):
            i += 1
            output_file = "{} ({}).mp4".format(basename, i)

        print("Encoding output video to: {}".format(output_file))
        subprocess.call([
            "ffmpeg",
            "-i", input_file,
            "-c:v", "libx264",  # h.264 video codec
            "-preset", "slow",  # encoding preset
            "-crf", "22",
            "-c:a", "aac",       # aac audio codec
            output_file,
        ])

if __name__ == "__main__":
    main()