How do i reformat a video file

Reformatting a video file means converting it from one format or codec to another. This process may be necessary for various reasons—compatibility with devices, editing requirements, file size reduction, improved streaming performance, or even uploading compliance for platforms like YouTube, Instagram, or TikTok.

Chapter 1: Video Formats and Codecs

Before jumping into how to reformat a video file, it’s crucial to understand what a video format actually is.

1.1 What is a Video Format?

A video format is the container used to bundle video, audio, and sometimes subtitles and metadata into one file. The most common video formats include:

MP4 (.mp4) – Universal support across devices and platforms.

AVI (.avi) – One of the oldest formats; supported widely but with large file sizes.

MKV (.mkv) – Popular for high-definition content; supports subtitles and multiple audio tracks.

MOV (.mov) – Developed by Apple; works best on macOS/iOS.

WMV (.wmv) – A Microsoft format optimized for Windows.

1.2 What is a Codec?

A codec (compressor-decompressor) determines how the video data is compressed and decompressed. Popular codecs include:

H.264 – Most widely used for compression and quality balance.

H.265 (HEVC) – Successor to H.264; better compression but less compatibility.

VP9 – Developed by Google; open-source and used for web streaming.

AV1 – Next-gen codec with superior compression but newer.

You might have an MP4 video that uses the H.264 codec—or an MKV using H.265. Reformatting a video could mean changing either or both.

Chapter 2: Why Reformat a Video File?

There are many reasons to reformat a video:

2.1 Device Compatibility

Older smart TVs or mobile phones may not support newer formats or codecs.

2.2 Editing Requirements

Video editing software may require specific formats like MOV or ProRes.

2.3 Upload Restrictions

Websites such as Instagram or TikTok might reject unsupported formats or resolutions.

2.4 File Size

Converting from an uncompressed format to H.264 can significantly reduce file size without noticeable loss in quality.

2.5 Playback Performance

Lowering resolution or bit rate can help videos run smoothly on low-end devices.

Chapter 3: Tools for Reformatting Video Files

You can reformat videos using desktop software, online converters, or command-line tools.

3.1 Desktop Software

A. HandBrake (Free)

Cross-platform (Windows, Mac, Linux)

Supports MP4 and MKV

Custom presets for web, devices, and more

B. Any Video Converter

Supports dozens of input/output formats

Built-in DVD burning

Audio and subtitle editing

C. Wondershare UniConverter

Batch conversion

Device-specific presets

GPU acceleration for faster performance

3.2 Online Video Converters

Ideal for short videos or quick tasks.

A. CloudConvert

Supports over 200 file types

Custom settings for resolution, codec, etc.

B. Online-Convert.com

Offers file format presets

Useful for quick edits

⚠️ Note: Online tools may limit file size or introduce watermarks in free versions.

3.3 Command-Line Tools

For advanced users who want maximum control.

A. FFmpeg

Powerful and flexible

Handles nearly any format or codec

Open-source and cross-platform

Chapter 4: How to Reformat a Video File – Step-by-Step

Let’s go over how to do this using various methods.

4.1 Reformatting with HandBrake

Step 1: Download & Install

Visit handbrake.fr and install the appropriate version.

Step 2: Launch the Application

Open HandBrake and click “File” to choose your video.

Step 3: Select Output Format

Choose MP4 or MKV as the container.

Step 4: Choose Presets

Use presets like “Fast 1080p30” or “Android 720p” depending on your target.

Step 5: Customize Settings (Optional)

Change codec (e.g., from H.264 to H.265)

Adjust resolution, frame rate, or bit rate

Step 6: Select Save Location

Click “Browse” to choose the destination folder.

Step 7: Start Encoding

Click “Start Encode.” The progress bar will indicate completion.

4.2 Reformatting with FFmpeg

If you’re comfortable with command-line tools:

bash

CopyEdit

ffmpeg -i input.avi -c:v libx264 -preset fast -crf 23 -c:a aac output.mp4

Explanation:

-i input.avi: Input file

-c:v libx264: Convert video to H.264

-crf 23: Constant Rate Factor (lower is better quality)

-c:a aac: Convert audio to AAC

output.mp4: Output file

To convert to MKV:

bash

CopyEdit

ffmpeg -i input.mov -c copy output.mkv

4.3 Reformatting Using Online Tools (CloudConvert)

Step 1: Go to cloudconvert.com

Step 2: Upload Your File

Step 3: Choose Target Format (e.g., MOV to MP4)

Step 4: Adjust Optional Settings (resolution, codec, etc.)

Step 5: Click Convert

Step 6: Download Result

Chapter 5: Best Format for Specific Use Cases

5.1 For Social Media (Instagram, TikTok, YouTube)

Format: MP4

Codec: H.264

Audio: AAC

Resolution: 1080p or 720p

5.2 For Editing (Premiere Pro, Final Cut)

Format: MOV or ProRes

Codec: Apple ProRes (for macOS) or DNxHD (for Windows)

Audio: PCM or AAC

5.3 For Archiving

Format: MKV

Codec: H.264 or H.265

Audio: FLAC for lossless

5.4 For Playback on TV/Consoles

Format: MP4 or MKV

Codec: H.264

Resolution: Match the TV (e.g., 1080p)

Chapter 6: Tips to Optimize Your Video Conversion

6.1 Maintain Quality While Reducing Size

Use CRF 18–23 in HandBrake or FFmpeg for balance.

Avoid re-encoding audio unless needed.

6.2 Convert in Batches

Most tools support batch conversion. Save time by loading multiple files.

6.3 Watch File Size

1 minute of 1080p H.264 video = ~50MB at 5 Mbps

Reduce bit rate or resolution if you need smaller files

6.4 Use Hardware Acceleration

Enable GPU encoding in apps like HandBrake or UniConverter if supported.

Chapter 7: Troubleshooting Common Issues

Problem 1: Audio Sync Issues

Use constant frame rate settings (CFR) instead of variable (VFR).

FFmpeg: -r 30 -vsync 1

Problem 2: Output File is Too Large

Lower bit rate or resolution.

Use H.265 instead of H.264.

Problem 3: Converted File Won’t Play

Try a universal media player like VLC.

Check codec support on the target device.

Problem 4: Choppy Playback

Reduce resolution or re-encode with a more compatible codec.

Chapter 8: Advanced Features and Batch Automation

8.1 Add Subtitles

Use HandBrake’s “Subtitles” tab to add SRT files.

8.2 Merge Multiple Videos

FFmpeg: ffmpeg -f concat -i list.txt -c copy output.mp4

8.3 Extract Audio Only

ffmpeg -i input.mp4 -q:a 0 -map a output.mp3