Video Stream Generator

hls.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
'''
Please see https://tech.marksblogg.com/streaming-video-hls.html for more details on this script.

MIT License

Copyright (c) 2023 Mark Litwintschik

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
'''
import json
from   glob import glob
from   os import chdir, getcwd
from   os.path import splitext
from   pathlib import Path
from   shutil import move
from   tempfile import TemporaryDirectory
from   urllib.parse import quote

from   rich.progress import Progress, track
from   shpyx import run as execute
import typer


app = typer.Typer(rich_markup_mode='rich')


def get_length(filename: str, ffprobe: str):
    cmd = '%(ffprobe)s ' \
          '-v error ' \
          '-hide_banner ' \
          '-print_format json ' \
          '-show_streams ' \
          '"%(filename)s"'
    return float(json.loads(execute(cmd % {'filename': filename,
                                           'ffprobe': ffprobe}).stdout)
                    ['streams']
                    [0]
                    .get('duration', 0.0))


remove_ext = lambda filename: splitext(filename)[0]


def build_thumbnail(filename:          str,
                    ffmpeg:            str,
                    fps:               int,
                    height:            int,
                    n_seconds:         int,
                    secs_per_clip:     int,
                    qscale:            int,
                    compression_level: int):
    filename = remove_ext(filename)
    cmd = '%(ffmpeg)s ' \
          '-loglevel error ' \
          '-hide_banner ' \
          '-y '\
          '-i "%(filename)s.mp4" ' \
          '-vf "fps=%(fps)d,' \
                'scale=-1:%(height)d:flags=lanczos,' \
                'select=\'lt(mod(t,%(n_seconds)d),%(secs_per_clip)d)\',' \
                'setpts=N/FRAME_RATE/TB" ' \
          '-loop 0 ' \
          '-qscale %(qscale)d ' \
          '-compression_level %(compression_level)d ' \
          '"%(filename)s.webp"'
    if not Path(filename + '.webp').is_file():
        execute(cmd % {'filename': filename,
                       'ffmpeg': ffmpeg,
                       'fps': fps,
                       'height': height,
                       'n_seconds': n_seconds,
                       'secs_per_clip': secs_per_clip,
                       'qscale': qscale,
                       'compression_level': compression_level})


def ffmpeg_convert(filename: str,
                   ffmpeg:   str,
                   mp42hls:  str,
                   rate:     int,
                   bufsize:  int):
    cmd = '%(ffmpeg)s ' \
          '-i "%(filename)s" ' \
          '-loglevel error ' \
          '-hide_banner ' \
          '-y ' \
          '-c:v libx264 ' \
          '-preset ultrafast ' \
          '-b:v %(rate)dk ' \
          '-maxrate %(rate)dk ' \
          '-bufsize %(bufsize)dk ' \
          '-vf scale=-1:720 ' \
          'out.mp4'

    cmd2 = '%s out.mp4 --output-single-file' % mp42hls

    start_folder = getcwd()

    with TemporaryDirectory() as folder:
        chdir(folder)
        execute(cmd % {'filename': start_folder + '/' + filename,
                       'ffmpeg':   ffmpeg,
                       'rate':     rate,
                       'bufsize':  bufsize})
        execute(cmd2)

        filename = remove_ext(filename)

        iframes_m3u8 = open('iframes.m3u8', 'r')\
                        .read()\
                        .replace('stream.ts', '%s.ts' % filename)
        stream_m3u8 = open('stream.m3u8', 'r')\
                        .read()\
                        .replace('stream.ts', '%s.ts' % filename)

        chdir(start_folder)
        move("%s/stream.ts" % folder, "./%s.ts" % filename)
        open('%s.iframes.m3u8' % filename, 'w').write(iframes_m3u8)
        open('%s.stream.m3u8' % filename, 'w').write(stream_m3u8)


def generate_index():
    # Generate an index.html listing all .m3u8 files
    # and their .webp thumbnails.
    vid_html = '''
        <video controls
               preload="auto"
               video
               poster="%(filename)s.webp"
               data-setup='{"fluid":true,
                            "controls": true,
                            "autoplay": false,
                            "preload": "auto"}'
               width="100%%">
            <source src="%(filename)s.stream.m3u8"
                    type="application/x-mpegURL">
        </video>
        '''

    open('index.html', 'w')\
        .write('<hr/>'.join([vid_html % {'filename': quote(remove_ext(x))}
                             for x in sorted(glob('*.ts'))]))


alt_bin   = {'rich_help_panel': 'Alternative Binaries'}
vid_qual  = {'rich_help_panel': 'Video Quality'}
thumb_set = {'rich_help_panel': 'Thumbnail Settings'}
job_track = {'rich_help_panel': 'Job Tracking'}

@app.command()
def build(ffmpeg:                  str  = typer.Option('ffmpeg',  **alt_bin),
          ffprobe:                 str  = typer.Option('ffprobe', **alt_bin),
          mp42hls:                 str  = typer.Option('mp42hls', **alt_bin),
          rate:                    int  = typer.Option(4000,      **vid_qual),
          bufsize:                 int  = typer.Option(8000,      **vid_qual),
          thumb_fps:               int  = typer.Option(10,        **thumb_set),
          thumb_height:            int  = typer.Option(360,       **thumb_set),
          thumb_n_seconds:         int  = typer.Option(145,       **thumb_set),
          thumb_secs_per_clip:     int  = typer.Option(1,         **thumb_set),
          thumb_qscale:            int  = typer.Option(50,        **thumb_set),
          thumb_compression_level: int  = typer.Option(3,         **thumb_set)):
    # Find all MP4 files in folder without a corresponding .ts file.
    # This will skip videos already generated.
    workload = set([remove_ext(x)
                    for x in glob('*.mp4')]) - \
               set([remove_ext(x)
                    for x in glob('*.ts')])
    workload = set([x + '.mp4' for x in workload])
    workload2 = {}

    # Get length of videos.
    for filename in track(workload,
                          description='Fetching video lengths...'):
        workload2[filename] = get_length(filename, ffprobe)

    total_duration = sum(workload2.values())

    # Generate .ts and .m3u8 files starting with the shortest videos first
    with Progress() as progress:
        task = progress.add_task('Converting videos to HLS...',
                                 total=total_duration)
        for filename, duration in sorted(workload2.items(),
                                         key=lambda x: x[1]):
            build_thumbnail(filename=filename,
                            ffmpeg=ffmpeg,
                            fps=thumb_fps,
                            height=thumb_height,
                            n_seconds=thumb_n_seconds,
                            secs_per_clip=thumb_secs_per_clip,
                            qscale=thumb_qscale,
                            compression_level=thumb_compression_level)
            ffmpeg_convert(filename, ffmpeg, mp42hls, rate, bufsize)
            generate_index()
            progress.update(task, advance=duration)


if __name__ == "__main__":
    app()