File size: 4,582 Bytes
1425afc | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 | from __future__ import annotations
from pathlib import Path
from renderer.ffmpeg.command import FFmpegCommand
from renderer.ffmpeg.runner import FFmpegRunner
class AudioMixer:
def __init__(self, runner: FFmpegRunner) -> None:
self.runner = runner
def ducking_filter(self) -> str:
# sidechaincompress lowers background music while voiceover is active.
return (
"[1:a]volume=0.316[music_quiet];"
"[music_quiet][2:a]sidechaincompress=threshold=0.02:ratio=8:attack=30:release=600[ducked];"
"[2:a]volume=1.0[voice];"
"[ducked][voice]amix=inputs=2:duration=first:dropout_transition=2[aout]"
)
def mix(
self,
video: Path,
music: str | None,
voiceover: str | None,
output: Path,
normalize: bool = False,
*,
duration: float | None = None,
music_volume: float = 0.316,
music_fade_in: float = 0.0,
music_fade_out: float = 0.0,
music_loop: bool = True,
music_start: float = 0.0,
music_ducking: bool = True,
voice_volume: float = 1.0,
) -> Path:
audio_tail = ",loudnorm=I=-16:TP=-1.5:LRA=11" if normalize else ""
if not music and not voiceover:
command = FFmpegCommand().add("-hide_banner").input(video).add("-c", "copy").overwrite().add(output).build()
self.runner.run(command)
return output
if voiceover and music:
music_filter = _music_filter(
music_volume,
fade_in=music_fade_in,
fade_out=music_fade_out,
duration=duration,
)
if music_ducking:
ducking_filter = (
f"[1:a]{music_filter}[music];"
"[music][2:a]sidechaincompress=threshold=0.02:ratio=8:attack=30:release=600[ducked];"
f"[2:a]volume={voice_volume}[voice];"
"[ducked][voice]amix=inputs=2:duration=first:dropout_transition=2[aout]"
)
else:
ducking_filter = (
f"[1:a]{music_filter}[music];"
f"[2:a]volume={voice_volume}[voice];"
"[music][voice]amix=inputs=2:duration=first:dropout_transition=2[aout]"
)
if normalize:
ducking_filter += ";[aout]loudnorm=I=-16:TP=-1.5:LRA=11[anorm]"
audio_map = "[anorm]"
else:
audio_map = "[aout]"
command = (
FFmpegCommand()
.add("-hide_banner")
.input(video)
.input(music, **_music_input_options(music_loop, music_start))
.input(voiceover)
.add("-filter_complex", ducking_filter)
.add("-map", "0:v", "-map", audio_map, "-c:v", "copy", "-c:a", "aac", "-shortest")
.overwrite()
.add(output)
.build()
)
else:
audio = voiceover or music
input_options = {} if voiceover else _music_input_options(music_loop, music_start)
volume = voice_volume if voiceover else music_volume
audio_filter = f"volume={volume}"
if music and not voiceover:
audio_filter = _music_filter(music_volume, fade_in=music_fade_in, fade_out=music_fade_out, duration=duration)
command = (
FFmpegCommand()
.add("-hide_banner")
.input(video)
.input(audio, **input_options)
.add("-filter_complex", f"[1:a]{audio_filter}{audio_tail}[aout]")
.add("-map", "0:v", "-map", "[aout]", "-c:v", "copy", "-c:a", "aac", "-shortest")
.overwrite()
.add(output)
.build()
)
self.runner.run(command)
return output
def _music_input_options(loop: bool, start: float) -> dict[str, object]:
options: dict[str, object] = {}
if loop:
options["stream_loop"] = -1
if start > 0:
options["ss"] = start
return options
def _music_filter(volume: float, *, fade_in: float, fade_out: float, duration: float | None) -> str:
filters = [f"volume={volume}"]
if fade_in > 0:
filters.append(f"afade=t=in:st=0:d={fade_in}")
if fade_out > 0 and duration and duration > fade_out:
filters.append(f"afade=t=out:st={max(0.0, duration - fade_out):.3f}:d={fade_out}")
return ",".join(filters)
|