How I Converted 1,000+ CCTV .media Files to MP4 Using FFmpeg and a Bash Script

Muhammad Darwis — Sat, 14 Mar 2026 07:44:29 +0000

The Problem

My neighbor's car got scratched. They had CCTV footage — 3 days of recordings on a microSD card.

When we checked the files, every single one had a .media extension. No video player could open them. Most converter apps either choked on bulk files or wanted a subscription.

I suspected these were just regular video containers with a renamed extension — common with budget CCTV brands.

Step 1: Test with FFmpeg

ffmpeg -i "/path/to/0000.media" -c copy test_output.mp4

It worked. H.264 video wrapped in a .media container. FFmpeg read it without issues.

Step 2: Understand the File Structure

The microSD had a nested folder structure — thousands of 10-second .media chunks across subfolders.

Step 3: The Script

#!/bin/bash

INPUT_DIR="/path/to/cctv"
OUTPUT_DIR="/path/to/cctv_generated/output"
MERGED_DIR="/path/to/cctv_generated/merged"
CONCAT_LIST="/path/to/cctv_generated/concat_list.txt"
MERGED_OUTPUT="$MERGED_DIR/merged_final.mp4"

mkdir -p "$OUTPUT_DIR"
mkdir -p "$MERGED_DIR"
> "$CONCAT_LIST"

find "$INPUT_DIR" -name "*.media" | sort | while read -r f; do
  rel=$(echo "$f" | sed "s|$INPUT_DIR/||" | sed 's|/|_|g' | sed 's|\.media||')
  out="$OUTPUT_DIR/${rel}.mp4"

  ffmpeg -i "$f" -c copy "$out" -y 2>/dev/null

  if [ -f "$out" ] && [ -s "$out" ]; then
    echo "file '$out'" >> "$CONCAT_LIST"
  else
    echo "⚠️  Skipping (failed): $f"
  fi
done

ffmpeg -f concat -safe 0 -i "$CONCAT_LIST" -c copy "$MERGED_OUTPUT" -y
echo "✅ Done! Merged output: $MERGED_OUTPUT"

Why -c copy?

Instead of re-encoding (which takes hours), -c copy copies the raw stream directly into the new container.

For 1,000 files this means:

Minutes instead of hours
Zero quality loss
Negligible CPU usage

Result

~1,000 files converted and merged into a single 34-hour MP4. The whole process finished in under 15 minutes on a Mac Mini M-series.

A few files had moov atom not found errors — these were corrupt/incomplete recordings from the CCTV, safely skipped.

The Bigger Takeaway

Most "bulk video converter" websites? They're just wrappers around FFmpeg on a backend server. You're paying for a UI around a free, 20-year-old open-source CLI tool.

Next time you hit a file format problem — check if FFmpeg handles it first. It probably does.

FFmpeg docs: https://www.ffmpeg.org/

DEV Community: Muhammad Darwis