720x1080 批量转 1920x1080（两边黑屏）

手机直播的时候录播机录出来的分辨率是 720x1080，使用 ffmpeg 转成横屏的 1920x1080。这样 xml 转 ass 弹幕的时候，就不需要另外处理了，看起来很更舒服。

macos 的写法：

input_folder="" # 要转化的录播的文件夹路径
output_folder="" # 要输出的文件夹路径
 
# Create the output folder if it does not exist
mkdir -p "$output_folder"
 
for f in "$input_folder"/*.flv; do
  ffmpeg -i "$f" -vf "scale=720:1080,pad=1920:1080:(ow-iw)/2:(oh-ih)/2" -c:a copy "$output_folder/$(basename "${f%.*}.mp4")"
done

windows 的写法：

$input_folder = "Z:\\rec\\48743-hanser\\20240731-又来画画了！"  # 要转化的录播的文件夹路径
$output_folder = "Z:\\rec\\48743-hanser\\20240731-又来画画了！"  # 要输出的文件夹路径
 
# Create the output folder if it does not exist
If (-Not (Test-Path $output_folder)) {
    New-Item -ItemType Directory -Path $output_folder | Out-Null
}
 
Get-ChildItem -Path $input_folder -Filter *.flv | ForEach-Object {
    $input_file = $_.FullName
    $output_file = Join-Path $output_folder ($_.BaseName + ".mp4")
    $ffmpeg_args = @("-i", $input_file, "-vf", "scale=720:1080,pad=1920:1080:(ow-iw)/2:(oh-ih)/2", "-c:a", "copy", $output_file)
    & ffmpeg $ffmpeg_args
}

效果

弹幕压制

windows 版 (使用 cuda)

@echo off
set input_folder=YourInputFolderPath
set output_folder=YourOutputFolderPath
 
for a" -vf subtitles="~na_压制.mp4" -y
)

macOS 版

#!/bin/bash
 
input_folder="/path/to/input"  # Replace with your input folder path
output_folder="/path/to/output"  # Replace with your output folder path
 
mkdir -p "$output_folder"  # Create the output folder if it doesn't exist
 
for f in "$input_folder"/*.mp4; do
    subtitle_file="${f%.*}.ass"  # Assumes subtitle file name is same as video file name but with .ass extension
    output_file="$output_folder/$(basename "${f%.*}_压制.mp4")"  # Output file name with _ass suffix
 
    ffmpeg -i "$f" -vf "ass=$subtitle_file" "$output_file"
done