hls.sh

#!/bin/bash

# 信号处理函数
cleanup() {
    echo ""
    echo "Interrupted by user."
    exit 1
}

# 设置信号处理
trap cleanup SIGINT SIGTERM

# 解析命令行参数
while getopts "i:o:p:" opt; do
  case $opt in
    i) input="$OPTARG" ;;
    o) output="$OPTARG" ;;
    p) preset_arg="$OPTARG" ;;
    *) 
      echo "Usage: $0 -i <input> -o <output> -p <preset_resolution>"
      echo "Example: $0 -i video.mp4 -o output -p 720p"
      echo "Example: $0 -i video.mp4 -o output -p 720p,1080p,480p"
      echo "Preset resolutions: 480p, 720p, 1080p, 2k, 4k"
      exit 1
      ;;
  esac
done

if [ -z "$input" ]; then
    echo "Error: Please specify input file with -i"
    echo "Usage: $0 -i <input> -o <output> -p <preset_resolution>"
    exit 1
fi

if [ -z "$output" ]; then
    echo "Error: Please specify output directory with -o"
    echo "Usage: $0 -i <input> -o <output> -p <preset_resolution>"
    exit 1
fi

if [ -z "$preset_arg" ]; then
    echo "Error: Please specify preset resolution with -p"
    echo "Usage: $0 -i <input> -o <output> -p <preset_resolution>"
    exit 1
fi

# 检查输入文件是否存在
if [ ! -f "$input" ]; then
    echo "Error: Input file '$input' not found!"
    exit 1
fi

# 将预设参数按逗号分割
IFS=',' read -ra preset_array <<< "$preset_arg"

resolutions=(
    # SD
    "480p 854x480 600 64"
    # HD
    "720p 1280x720 2000 128"
    # FHD
    "1080p 1920x1080 3800 160"
    # QHD
    "2k 2560x1440 5000 160"
    # UHD
    "4k 3840x2160 6000 160"
)

# 验证所有预设参数
for preset in "${preset_array[@]}"; do
    preset_found=false
    for resolution in "${resolutions[@]}"; do
        preset_index=$(echo "$resolution" | awk '{print $1}')
        if [ "$preset_index" == "$preset" ]; then
            preset_found=true
            break
        fi
    done
    
    if [ "$preset_found" == false ]; then
        echo "Error: Preset resolution not found: $preset"
        echo "Available presets: 480p, 720p, 1080p, 2k, 4k"
        exit 1
    fi
done

max_fps=30
ac_num=2

# 读取视频码率（bps）
orig_vbr=$(ffprobe -v error -select_streams v:0 -show_entries stream=bit_rate \
  -of default=noprint_wrappers=1:nokey=1 "$input")

# 读取音频码率（bps）
orig_abr=$(ffprobe -v error -select_streams a:0 -show_entries stream=bit_rate \
  -of default=noprint_wrappers=1:nokey=1 "$input")

# 读取视频分辨率
orig_width=$(ffprobe -v error -select_streams v:0 -show_entries stream=width \
  -of default=noprint_wrappers=1:nokey=1 "$input")

# 读取视频分辨率
orig_height=$(ffprobe -v error -select_streams v:0 -show_entries stream=height \
  -of default=noprint_wrappers=1:nokey=1 "$input")

# 计算视频宽高比
if is_valid_number "$orig_width" && is_valid_number "$orig_height"; then
  orig_aspect_ratio=$(echo "$orig_width / $orig_height" | bc -l)
else
  orig_aspect_ratio=1.777777  # 默认16:9
fi

# 读取视频帧率
orig_fps=$(ffprobe -v error -select_streams v:0 -show_entries stream=r_frame_rate \
  -of default=noprint_wrappers=1:nokey=1 "$input")
orig_fps_val=$(echo "scale=2; $orig_fps" | bc)  # 转成小数

# 视频帧率判断
if [[ -z "$orig_fps" ]]; then
  fps=$max_fps
elif (( $(echo "$orig_fps_val < $max_fps" | bc -l) )); then
  fps=$(printf "%.0f" "$orig_fps_val")
else
  fps=$max_fps
fi

# 视频码率判断
if [[ -z "$orig_vbr" ]] || [[ "$orig_vbr" == "N/A" ]]; then
  vbr=$max_vbr
elif [[ "$orig_vbr" -gt "$max_vbr" ]]; then
  vbr=$max_vbr
else
  vbr=$orig_vbr
fi

# 音频码率判断
if [[ -z "$orig_abr" ]] || [[ "$orig_abr" == "N/A" ]]; then
  abr=$max_abr
elif [[ "$orig_abr" -gt "$max_abr" ]]; then
  abr=$max_abr
else
  abr=$orig_abr
fi

function format_kbps() {
  local value=$1
  if is_valid_number "$value"; then
    echo "$value" | awk '{printf "%.0f\n", $1/1000}'
  else
    echo "0"
  fi
}

function format_aspect_ratio() {
  local ratio=$1
  # 常见的宽高比
  if (( $(echo "$ratio > 1.7" | bc -l) )); then
    echo "16:9"
  elif (( $(echo "$ratio > 1.3" | bc -l) )); then
    echo "4:3"
  elif (( $(echo "$ratio > 1.1" | bc -l) )); then
    echo "3:2"
  elif (( $(echo "$ratio > 0.9" | bc -l) )); then
    echo "1:1"
  elif (( $(echo "$ratio > 0.7" | bc -l) )); then
    echo "3:4"
  elif (( $(echo "$ratio > 0.5" | bc -l) )); then
    echo "9:16"
  else
    echo "$(printf "%.2f" $ratio):1"
  fi
}

function is_valid_number() {
  local num=$1
  [[ -n "$num" && "$num" != "N/A" && "$num" -gt 0 ]] 2>/dev/null
}

echo "Input: $input"
echo "Output: $output"
echo "Presets: ${preset_array[*]}"
echo "Original: ${orig_width}x${orig_height} (aspect ratio: $(format_aspect_ratio $orig_aspect_ratio))"
echo "FPS: ${fps}fps (max: ${max_fps}fps)"

# 为每个预设分辨率进行转码
for preset in "${preset_array[@]}"; do
    echo ""
    echo "=== Processing $preset ==="
    
    # 查找对应的分辨率配置
    for resolution in "${resolutions[@]}"; do
        preset_index=$(echo "$resolution" | awk '{print $1}')
        
        if [ "$preset_index" == "$preset" ]; then
            max_vbr=$(echo "$resolution" | awk '{print $3}')
            max_abr=$(echo "$resolution" | awk '{print $4}')
            max_scale=$(echo "$resolution" | awk '{print $2}')
            
            max_vbr=$(echo "$max_vbr * 1000" | bc)
            max_abr=$(echo "$max_abr * 1000" | bc)
            break
        fi
    done
    
    # 计算最大分辨率
    max_width=$(echo "$max_scale" | cut -d'x' -f1)
    max_height=$(echo "$max_scale" | cut -d'x' -f2)
    
    # 保持宽高比的缩放计算
    if is_valid_number "$orig_width" && is_valid_number "$orig_height" && is_valid_number "$max_width" && is_valid_number "$max_height"; then
      if (( $(echo "$orig_width / $orig_height > $max_width / $max_height" | bc -l) )); then
          # 原视频更宽，以宽度为基准缩放
          target_width=$max_width
          target_height=$(echo "$orig_height * $max_width / $orig_width" | bc)
      else
          # 原视频更高，以高度为基准缩放
          target_height=$max_height
          target_width=$(echo "$orig_width * $max_height / $orig_height" | bc)
      fi
    else
      # 使用默认值
      target_width=$max_width
      target_height=$max_height
    fi
    
    # 确保分辨率是偶数（H.264要求）
    target_width=$((target_width / 2 * 2))
    target_height=$((target_height / 2 * 2))
    
    # 视频码率判断
    if [[ -z "$orig_vbr" ]] || [[ "$orig_vbr" == "N/A" ]]; then
      vbr=$max_vbr
    elif [[ "$orig_vbr" -gt "$max_vbr" ]]; then
      vbr=$max_vbr
    else
      vbr=$orig_vbr
    fi
    
    # 音频码率判断
    if [[ -z "$orig_abr" ]] || [[ "$orig_abr" == "N/A" ]]; then
      abr=$max_abr
    elif [[ "$orig_abr" -gt "$max_abr" ]]; then
      abr=$max_abr
    else
      abr=$orig_abr
    fi
    
    echo "Target: ${target_width}x${target_height} (max: ${max_scale})"
    echo "VBR: $(format_kbps $vbr)kbps (max: $(format_kbps $max_vbr)kbps)"
    echo "ABR: $(format_kbps $abr)kbps (max: $(format_kbps $max_abr)kbps)"
    
    output_dir="$output/${preset_index}"
    # 创建输出目录
    mkdir -p "$output_dir"
    
    # 转码
    ffmpeg -y -i "$input" \
      -map_metadata -1 \
      -c:v libx264 -b:v $vbr -maxrate $vbr -bufsize $((vbr * 2)) \
      -vf scale=$target_width:$target_height \
      -preset veryfast -r $fps -g $fps \
      -c:a aac -b:a $abr \
      -hls_time 10 -hls_list_size 0 \
      -hls_segment_filename "$output_dir/%03d.ts" \
      -f hls "$output_dir/playlist.m3u8"
    
    # 检查FFmpeg是否成功
    if [ $? -ne 0 ]; then
        echo "Error: FFmpeg failed for $preset"
        exit 1
    fi
    
    echo "Completed: $preset -> $output_dir/"
done