ytdl-sub/src/ytdl_sub/utils/ffmpeg.py

156 lines
4.7 KiB
Python

import subprocess
import tempfile
from typing import Dict
from typing import List
from typing import Optional
from ytdl_sub.utils.chapters import Chapters
from ytdl_sub.utils.exceptions import ValidationException
from ytdl_sub.utils.file_handler import FileHandler
from ytdl_sub.utils.logger import Logger
logger = Logger.get(name="ffmpeg")
_FFMPEG_METADATA_SPECIAL_CHARS = ["=", ";", "#", "\n", "\\"]
def _ffmpeg_metadata_escape(str_to_escape: str) -> str:
# backslash at the end of the list is intentional
for special_char in _FFMPEG_METADATA_SPECIAL_CHARS:
str_to_escape.replace(special_char, f"\\{special_char}")
return str_to_escape
class FFMPEG:
@classmethod
def _ensure_installed(cls):
try:
subprocess.check_output(["which", "ffmpeg"])
except subprocess.CalledProcessError as subprocess_error:
raise ValidationException(
"Trying to use a feature which requires ffmpeg, but it cannot be found"
) from subprocess_error
@classmethod
def run(cls, ffmpeg_args: List[str]) -> None:
"""
Runs an ffmpeg command. Should not include 'ffmpeg' as the beginning argument.
Parameters
----------
ffmpeg_args:
Arguments to pass to ffmpeg. Each one will be separated by a space.
"""
cls._ensure_installed()
cmd = ["ffmpeg"]
cmd.extend(ffmpeg_args)
logger.debug("Running %s", " ".join(cmd))
with Logger.handle_external_logs(name="ffmpeg"):
subprocess.run(cmd, check=True, capture_output=True)
def _create_metadata_chapter_entry(start_sec: int, end_sec: int, title: str) -> List[str]:
return [
"",
"[CHAPTER]",
"TIMEBASE=1/1000",
f"START={start_sec * 1000}",
f"END={end_sec * 1000}",
f"title={_ffmpeg_metadata_escape(title)}",
]
def _create_metadata_chapters(chapters: Chapters, file_duration_sec: int) -> List[str]:
lines: List[str] = []
if not chapters.contains_zero_timestamp():
lines += _create_metadata_chapter_entry(
start_sec=0,
end_sec=chapters.timestamps[0].timestamp_sec,
title="Intro", # TODO: make this configurable
)
for idx in range(len(chapters.timestamps) - 1):
lines += _create_metadata_chapter_entry(
start_sec=chapters.timestamps[idx].timestamp_sec,
end_sec=chapters.timestamps[idx + 1].timestamp_sec,
title=chapters.titles[idx],
)
# Add the last chapter using the file duration
lines += _create_metadata_chapter_entry(
start_sec=chapters.timestamps[-1].timestamp_sec,
end_sec=file_duration_sec,
title=chapters.titles[-1],
)
return lines
def set_ffmpeg_metadata_chapters(
file_path: str, chapters: Optional[Chapters], file_duration_sec: int
) -> None:
"""
Sets ffmetadata chapters to a file. Note that this will (I think) wipe all prior
metadata.
Parameters
----------
file_path
Full path to the file to add metadata to
chapters
Chapters to embed in the file. If a chapter for 0:00 does not exist, one is created
file_duration_sec
Length of the file in seconds
"""
lines = [";FFMETADATA1"]
if chapters:
lines += _create_metadata_chapters(chapters=chapters, file_duration_sec=file_duration_sec)
file_path_ext = file_path.split(".")[-1]
output_file_path = f"{file_path}.out.{file_path_ext}"
with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", encoding="utf-8") as metadata_file:
metadata_file.write("\n".join(lines))
metadata_file.flush()
FFMPEG.run(
[
"-i",
file_path,
"-i",
metadata_file.name,
"-map",
"0",
"-map_chapters",
"1",
"-bitexact", # for reproducibility
"-codec",
"copy",
output_file_path,
]
)
FileHandler.move(output_file_path, file_path)
def add_ffmpeg_metadata_key_values(file_path: str, key_values: Dict[str, str]) -> None:
"""
Parameters
----------
file_path
File to add metadata key/values to
key_values
The key/values to add
"""
file_path_ext = file_path.split(".")[-1]
output_file_path = f"{file_path}.out.{file_path_ext}"
ffmpeg_args = ["-i", file_path, "-map", "0"]
for key, value in key_values.items():
ffmpeg_args.extend(["-metadata", f"{key}={value}"])
ffmpeg_args.extend(["-codec", "copy", output_file_path])
FFMPEG.run(ffmpeg_args)
FileHandler.move(output_file_path, file_path)