Bilidown

A Bilibili video downloader built with Nim using direct API calls.

Features

• Download Bilibili videos by URL or BV ID
• Download audio-only streams (M4A format)
• Direct API integration with Bilibili's official APIs
• Support for multiple video qualities (240P to 8K)
• DASH format support with separate video and audio streams
• Automatic merging of video and audio streams using ffmpeg
• Progress indication during download

Requirements

• ffmpeg (for merging video and audio streams)

Usage

Command Line

# Download by URL
bilidown https://www.bilibili.com/video/BV1xx411c7mD

# Download by BV ID
bilidown BV1xx411c7mD

# Specify output directory
bilidown -u https://www.bilibili.com/video/BV1xx411c7mD -o ./videos

# Specify quality
bilidown -u BV1xx411c7mD -q 120  # 4K quality

# Download audio only
bilidown -u BV1xx411c7mD -a
bilidown --audio-only https://www.bilibili.com/video/BV1xx411c7mD -o ./music

Options

Options:
  -u, --url <url>        Bilibili video URL or BV ID
  -o, --output <dir>     Output directory (default: ./downloads)
  -q, --quality <q>      Video quality number (default: 80)
  -a, --audio-only       Download audio only (M4A format)
  -h, --help             Show this help

Quality Options

Library Usage

import bilidown

# Simple synchronous download
let outputPath = downloadBilibiliVideo(
  "https://www.bilibili.com/video/BV1xx411c7mD",
  outputDir = "./downloads",
  quality = vq1080P
)
echo "Downloaded to: " & outputPath

# Async usage
import asyncdispatch

proc asyncDownload() {.async.} =
  let downloader = newBiliDownloader()
  try:
    let outputPath = await downloader.download(
      "https://www.bilibili.com/video/BV1xx411c7mD",
      "./downloads",
      vq1080P
    )
    echo "Downloaded to: " & outputPath
  finally:
    await downloader.close()

waitFor asyncDownload()

# Audio-only download
let audioPath = downloadBilibiliAudio(
  "https://www.bilibili.com/video/BV1xx411c7mD",
  outputDir = "./music"
)
echo "Audio downloaded to: " & audioPath

How It Works

1. Extract BV ID: Parse the Bilibili URL to extract the BV ID
2. Get Video Info: Call Bilibili's video info API to get metadata and CID
3. Get Stream URLs: Call the playurl API to get DASH stream URLs with proper parameters
4. Parse Response: Use robust JSON parsing with std/json and manual field validation
5. Download Streams: Download video and audio streams with proper headers
6. Merge: Use ffmpeg to merge video and audio into a single MP4 file

Key Implementation Details

API Integration

• Direct calls to Bilibili's official APIs:
• /x/web-interface/view for video metadata
• /x/player/wbi/playurl for stream URLs
• Proper parameter handling with quality selection
• WBI signature support (when enabled)

Limitations

• Some videos may require login (not yet supported)
• Region-restricted videos may not be downloadable
• ffmpeg is required for merging audio and video streams
• WBI signature is currently disabled but can be enabled

License

MIT