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Lets see how everything works in FFmpeg.py

Input

The ffmpeg takes input in [-key value -i path], ffmpeg.py will make a input with InputFile or VideoFile. Both of them are does same thing but with VideoFile it comes with addition features like:

  • subclip that sets -ss and -t for seek start and duration repectively
  • from_imagefile that sets -t for duration and enable loop.
  • general streams like video, audio and subtitles that corresponds to stream_name:v:n in both filter and map context in command.
from ffmpeg import InputFile, FileInputOptions

clip = InputFile("video.mp4", FileInputOptions(duration=10, frame_rate=24))

It will create this command piece by running clip.build_input_flags().

['-t', '10', '-r', '24', '-i', 'video.mp4']

Global flags

Global flags are used change settings for whole runtime, you can use add_global_flag to set custom flags, These flags are automatic added duration command generation in FFmpeg.compile():

  • -y or -n to set overwrite outfile
  • -loglevel error to only read errors
  • -hide_banner to avoid extra pipe writes and cleaner output.

Usage

The add_global_flag take raw flags example as: 

FFmpeg().add_global_flag("-recast_media")

## Results ffmpeg -recast_media -i ....

Filters

Filters are way the ffmpeg allow media to be manipulated, ffmpeg.py use apply or apply2, apply2 is for multi output filters. Filter output can be exported or further filtered.

Usage

The apply functions take Filter and then the input to be filtered

apply(Filter, clip)

Example

Lets make a video logo overlay both scaled.

from ffmpeg import FFmpeg, Map, InputFile, VideoFile
from ffmpeg.filters import apply, Scale, Overlay


logo = InputFile(
    "image.png",
)

scaled_logo = apply(Scale(200, 200), logo)

video = VideoFile(
    "video.mp4",
)

scaled_video = apply(Scale(1920, 1080), video)

final_video = apply(Overlay(scaled_logo, 0, 0),scaled_video)


(
    FFmpeg()
    .output(Map(final_video), path="out.mp4")
    .run()
)
# Results 
# ffmpeg -hide_banner -y -loglevel error -i image.png -i video.mp4 \
# -filter_complex [0]scale=width=200:height=200[n0o0]; \
#                 [1]scale=width=1920:height=1080[n1o0];\
#                 [n1o0][n0o0]overlay=x=0:y=0[n2o0] \
#  -map [n2o0] out.mp4

Multiple Outputs

ffmpeg.py supports multiple output in single command by simply calling one more output. Lets use previous example. Here we are export the video and scaled logo

from ffmpeg import FFmpeg, Map, InputFile, VideoFile
from ffmpeg.filters import apply, Scale, Overlay


logo = InputFile(
    "image.png",
)

scaled_logo = apply(Scale(200, 200), logo)

video = VideoFile(
    "video.mp4",
)

scaled_video = apply(Scale(1920, 1080), video)

final_video = apply(Overlay(scaled_logo, 0, 0), scaled_video)


(
    FFmpeg()
    .output(Map(final_video), path="out.mp4")
    .output(Map(scaled_logo), path="scaled_logo.png")
    .run()
)

# Results 
# ffmpeg -hide_banner -y -loglevel error -i image.png -i video.mp4
# -filter_complex [0]scale=width=200:height=200[n0o0]; \
#                 [1]scale=width=1920:height=1080[n1o0];\
#                 [n1o0][n0o0]overlay=x=0:y=0[n2o0]\
# -map [n2o0] out.mp4 
# -map [n0o0] scaled_logo.png

Map Flags

We also need to set -map flags when exporting like setting fps or bitrate to do that we will set them in Map context

Use suffix_flags when a flags requires a suffix like -r:1 or -r:v:1 otherwise kwargs will catch all normal flags.

(
    FFmpeg()
    .output(Map(final_video,), path="out.mp4")
    .output(Map(scaled_logo), path="scaled_logo.png")
    .run()
)