Better FFmpeg Progress

Runs an FFmpeg command and shows a progress bar with percentage progress, elapsed time and ETA.

FFmpeg outputs something like:

frame=  692 fps= 58 q=28.0 size=    5376KiB time=00:00:28.77 bitrate=1530.3kbits/s speed=2.43x

Better FFmpeg Progress outputs something like:

⠏ Processing abc.webm (5.50 MB / ~23.91 MB) ━━━━━━━━━╺━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━  23% 0:00:04 00:15

Where:

• Processing abc.webm is the description of the progresss bar. Filenames longer than 60 characters are truncated.
• (5.50 MB / ~23.91 MB) is the current output size and the estimated final output size.
• 23% is the percentage progress.
• 0:00:04 is the time elapsed.
• 00:15 is the estimated time until the FFmpeg process completes.

Installation

pip install better-ffmpeg-progress --upgrade

Usage

Create an instance of the FfmpegProcess class and supply a list of arguments like you would when using subprocess.run() or subprocess.Popen(). Example:

from better_ffmpeg_progress import FfmpegProcess, FfmpegProcessError

command = [
    "ffmpeg",
    "-i",
    "https://media.xiph.org/video/derf/y4m/ducks_take_off_1080p50.y4m",
    "-map",
    "0:V",
    "-c:V",
    "libx264",
    "-preset",
    "ultrafast",
    "-f",
    "null",
    "-",
]

try:
    # Pass use_tqdm=True to use tqdm instead of Rich.
    process = FfmpegProcess(command)

    process.run()
except FfmpegProcessError as e:
    print(
        "An error occurred when running Better FFmpeg Progress:\n"
        f"{e}"
    )

Trimming

If your command trims the input with -ss, -sseof, -t or -to (as input or output options), the expected duration of the output is calculated automatically, so the progress bar and ETA reflect the trimmed output rather than the whole input file. This adjustment is skipped when -copyts is used.

Duration Override

By default, Better FFmpeg Progress detects the duration of the input file and uses it to calculate percentage progress and ETA.

For partial, damaged, streamed or synthetic inputs, FFmpeg may be unable to detect the duration correctly. In these cases, you can provide the duration manually using duration_override.

The value should be the duration of the input file, in seconds:

from better_ffmpeg_progress import FfmpegProcess

command = [
    "ffmpeg",
    "-i",
    "partial-input.flv",
    "-c",
    "copy",
    "recovered-output.mkv",
]

process = FfmpegProcess(
    command,
    duration_override=1222.64,
    print_detected_duration=True,
)

process.run()

Generated (lavfi) Inputs

Inputs generated by FFmpeg's lavfi device, such as test patterns, are supported. FFprobe cannot detect the duration of these inputs, so provide it with duration_override:

from better_ffmpeg_progress import FfmpegProcess

command = [
    "ffmpeg",
    "-f",
    "lavfi",
    "-i",
    "testsrc2=duration=30:size=1920x1080:rate=30",
    "-c:v",
    "libx264",
    "output.mp4",
]

process = FfmpegProcess(command, duration_override=30)
process.run()

By default, the FFmpeg log file is named after the source, e.g. lavfi_testsrc2_ffmpeg_log.txt.

Optional Arguments

An instance of FfmpegProcess accepts the following optional arguments:

• ffmpeg_log_level — Set a value for FFmpeg's -loglevel option. Default: "verbose".
• ffmpeg_log_file — Filepath or file-like object to which FFmpeg stderr will be written. Default: <input filename>_ffmpeg_log.txt.
• print_detected_duration — Print the detected duration. Default: False.
• duration_override — Specify input file duration in seconds to use for progress calculation, instead of trying to detect this automatically with FFprobe. Default: None.
• use_tqdm — Use tqdm instead of Rich for the progress bar. Default: False.
• overwrite — What to do if the output file already exists: True overwrites it, False raises FfmpegCommandError, and None asks whether to overwrite it. Ignored if the command contains -y or -n. Default: None.

The run method accepts the following optional argument:

• print_command — Print the FFmpeg command being executed. Default: False.

Using tqdm

By default, the Rich library is used to display a progress bar. tqdm can be used instead by passing use_tqdm=True:

process = FfmpegProcess(command, use_tqdm=True)
process.run()

Limitations

• Progress is calculated from the duration of the first input (the first -i).
• The last argument of the command is treated as the output file, e.g. when checking whether it already exists. With multiple outputs, only the last one is checked.

Development

Install the package in editable mode with the test dependencies, then run the tests (FFmpeg and FFprobe must be installed):

pip install -e ".[test]"

pytest

test.py is a standalone example that encodes a test pattern and shows the progress bar.

Publishing

Update __version__ in better_ffmpeg_progress/__init__.py and add an entry to CHANGELOG.md.

One-time setup:

python -m pip install --upgrade build twine pkginfo

Then, for each release:

rm -rf dist

python -m build

python -m twine check dist/*

python -m twine upload dist/*