SSDown Logo
Back to Home
May 5, 2024
5 min read
SSDown Engineering Team

Under the Hood: How We Made SSDown 3x Faster in 2024 (Infrastructure Update)

#news#update#engineering#speed#bilibili

The Need for Speed

In the world of video downloading, a delay of 5 seconds feels like an eternity. As SSDown grew from a small utility to a global platform with users from Brazil to South Korea, our monolith server architecture started to show cracks. During peak hours (Saturday nights in Asia / Sunday mornings in US), processing times for 4K videos were unacceptable.

We decided to stop patching holes and rebuild our core infrastructure. Here is what changed.

1. Global Edge Nodes (CDN Expansion)

Previously, all requests were routed to our central servers in the US. This meant a user in Tokyo had to send a request across the Pacific Ocean, wait for processing, and receive the file back. The latency (ping) alone was 200ms+.

The Upgrade: We have deployed "Edge Worker Nodes" in strategic locations:

  • Tokyo (JP): Handling East Asia traffic (Korea, Japan).
  • Singapore (SG): Handling Southeast Asia.
  • Frankfurt (DE): Serving Europe.
  • São Paulo (BR): Serving South America.

The Result:

  • Latency reduced by 70%.
  • Download speeds are no longer capped by trans-oceanic cable bandwidth. You download from a server near you.

2. The "Bilibili Engine" Rewrite

Bilibili is notoriously difficult to download from. They separate audio (.m4a) and video (.m4v) tracks to save bandwidth. To give you a playable MP4, we have to download both and "stitch" them together (a process called Remuxing) using FFmpeg.

The Problem: FFmpeg is CPU intensive. When 1,000 users downloaded Bilibili videos simultaneously, our CPUs hit 100% usage, creating a queue.

The Solution: We implemented a GPU-Accelerated Transcoding Pipeline.

  • We moved the remuxing task from general-purpose CPUs to specialized transcoding cards.
  • We optimized the buffer size to process streams in chunks rather than waiting for the whole file.
  • Performance Gain: 1080p/60fps videos from Bilibili now process 4x faster.

3. TikTok & Instagram: Adaptive Parsing

Social media platforms are constantly fighting scrapers. They change their HTML structure, obfuscate their JavaScript, and rotate API keys daily. Previously, when TikTok updated their code, SSDown would go down for 2-3 hours while our engineers manually fixed the scraper.

The Evolution: We built an AI-Assisted Parser.

  • Our system continuously monitors the target sites.
  • If it detects a change (e.g., download failure rate spikes > 1%), it automatically attempts to identify the new pattern using machine learning models trained on thousands of page variants.
  • It can often "self-heal" and adapt to minor code changes without human intervention.
  • This means 99.9% Uptime for you.

4. Bandwidth Upgrade

We negotiated new transit agreements with Tier-1 network providers.

  • Old Capacity: 1 Gbps port per server.
  • New Capacity: 10 Gbps port per server.

Even if you are on a Gigabit Fiber connection at home, SSDown can now fully saturate your internet speed. You can download a 1GB file in seconds.

What's Next? (Roadmap)

We are not done. Here is what we are working on for Late 2024:

  • 8K Support: YouTube allows 8K AV1 streams. We are testing the hardware required to process these massive files.
  • Batch Downloading: The ability to paste a link to a TikTok profile and download all their videos at once (Premium feature concept).
  • Cloud Drive Integration: Save directly to your Google Drive or Dropbox without downloading to your device first.

A Note of Thanks

Infrastructure costs money. Bandwidth costs money. Yet, SSDown remains free. This is possible because of our loyal users who disable ad-blockers or share our site with friends. Your support fuels these upgrades.

Enjoy the speed.