MP4 to AVI Converter

What is MP4 to AVI Conversion?

MP4 to AVI conversion is the process of transforming a video file from a modern universal format into a classic container developed by Microsoft. This involves repackaging the video and audio streams into an AVI file structure, with preservation or modification of the codecs used depending on compatibility requirements.

MP4 (MPEG-4 Part 14) is the most widely used video format today, supporting advanced compression codecs such as H.264, H.265/HEVC, and AV1. The format delivers excellent quality at moderate file sizes and plays on all modern devices - from smartphones to Smart TVs.

AVI (Audio Video Interleave) was introduced by Microsoft in 1992 as part of Video for Windows technology. Despite its age, the format remains popular due to its extensive compatibility with various hardware: DVD players, media centers, car stereos, older generation gaming consoles, and industrial surveillance systems.

During MP4 to AVI conversion, the container structure changes and, if necessary, the stream encoding method is modified. Depending on conversion settings, the video may be re-encoded to a codec more compatible with target devices, or simply repackaged into a new container without changing the compression.

Technical Differences Between MP4 and AVI Formats

Container Architecture

MP4 is built on the Apple QuickTime format and uses an atomic data structure. The file is divided into blocks (atoms), each containing a specific type of information: metadata, video stream, audio tracks, subtitles. This structure provides flexibility and streaming capability but requires full header reading to determine the content.

AVI uses the RIFF (Resource Interchange File Format) structure, where data is organized as nested chunks. Video and audio are interleaved to ensure synchronized playback without buffering. This simple architecture ensures reliable playback on low-powered devices.

Codec and Feature Support

MP4's key advantage is support for modern codecs with high compression ratios. AVI works better with classic codecs and ensures compatibility with equipment released before 2010.

File Size Comparison

When using the same video codec, file sizes are virtually identical - the container adds minimal overhead:

The increase in AVI file size with Xvid codec is explained by less efficient compression compared to H.264, but such files are more compatible with older DVD players.

When MP4 to AVI Conversion is Necessary

Compatibility with Older DVD Players

Many DVD players released between 2000-2010 don't support MP4 format but play AVI files perfectly:

• DVD players without DivX HD support - classic models from Sony, Philips, LG, Samsung recognize AVI with DivX or Xvid codec
• Portable DVD players - compact devices for cars and travel
• DVD/VHS combo units - hybrid players for different media types
• Budget Chinese players - inexpensive devices with limited format support

For these devices, converting to AVI with Xvid or DivX codec is the only way to play modern video recordings.

Car Media Systems

Factory and aftermarket car stereos often have limited video format support:

• Factory head units - especially in cars from 2005-2015
• 2-DIN Android radios - budget models with limited codec sets
• Headrest monitors - entertainment systems for rear passengers
• Overhead monitors - flip-down screens in minivans and SUVs

AVI files with compatible parameters are guaranteed to play on most car systems.

Industrial and Specialized Equipment

AVI format remains the standard for many professional systems:

• Video surveillance systems - DVR/NVR recorders often only record and play AVI
• Medical equipment - endoscopes, ultrasound machines, surgical systems
• Industrial cameras - quality control systems, microscopes
• Laboratory equipment - high-speed cameras, analytical instruments
• Digital signage - advertising screens with built-in media players

These systems often operate for decades without updates, and AVI remains their primary format.

Older Generation Gaming Consoles

Some gaming consoles only support video playback in AVI format:

• PlayStation 2 - with installed media player
• Original Xbox - through XBMC or alternative firmware
• PlayStation Portable (PSP) - using third-party players
• Nintendo Wii - through Homebrew applications

For retro console owners, AVI conversion is a way to use them as media centers.

Conversion Process: What Happens to the File

Conversion Options

When converting MP4 to AVI, two scenarios are possible:

Remuxing - if the source video is encoded with a compatible codec (e.g., MPEG-4 Part 2), streams can simply be transferred to an AVI container without re-encoding. This is a fast process with no quality loss.

Transcoding - if the source codec is incompatible with the target device (e.g., H.265), the video is re-encoded to a compatible format (Xvid, DivX). This takes more time and may slightly reduce quality.

Transformation Steps

1. Input file analysis - determining video and audio codecs, resolution, frame rate, bitrate, subtitles and metadata presence

2. Conversion mode selection - deciding on remuxing or transcoding based on codec compatibility

3. Video stream processing - decoding source video (during transcoding), applying quality settings, encoding to target format

4. Audio stream processing - converting audio to compatible format (usually MP3 or AC3), adjusting bitrate and channels

5. Multiplexing - combining video and audio into AVI structure with proper data interleaving for synchronized playback

6. Metadata writing - adding basic file information (title, author, date)

What is Preserved During Conversion

• Video content - all frames from the source video are transferred to the result
• Main audio track - sound is preserved, possibly with re-encoding
• Duration - video length doesn't change
• Aspect ratio - frame proportions are preserved

What May Be Lost

• Additional audio tracks - AVI poorly supports multiple sound tracks
• Embedded subtitles - transferred to external SRT files
• Chapters and sections - AVI doesn't support chapter navigation
• Extended metadata - tags, covers, comments may not be preserved
• HDR information - the format doesn't support high dynamic range

Quality Settings During Conversion

Video Codec Selection

The codec determines compatibility with target devices:

For guaranteed compatibility with older equipment, choose Xvid or MPEG-4.

Video Resolution

Target resolution depends on playback device capabilities:

• 1920x1080 (Full HD) - for modern media players with high resolution support
• 1280x720 (HD) - optimal balance of quality and compatibility
• 720x480 (DVD NTSC) - standard for North American DVD players
• 720x576 (DVD PAL) - standard for European DVD players
• 640x480 (VGA) - for older devices with limited support

When converting for DVD players, using DVD-standard resolution (720x480 or 720x576) is recommended.

Bitrate and Quality

Compression parameters affect image quality and file size:

• High bitrate (5000-8000 Kbps) - minimal compression artifacts, larger file size
• Medium bitrate (2000-4000 Kbps) - optimal balance for most cases
• Low bitrate (1000-2000 Kbps) - noticeable compression, compact file

Audio Settings

Audio parameters for maximum compatibility:

• Codec - MP3 (universal compatibility) or AC3 (for multichannel audio systems)
• Bitrate - 128-320 Kbps for MP3, 384-640 Kbps for AC3
• Channels - stereo (2 channels) for most devices
• Sample rate - 44100 or 48000 Hz

Advantages of AVI Format

Universal Compatibility

AVI format plays on the widest range of devices:

• Virtually all DVD players with USB support
• Car stereos and media centers
• TVs with built-in media players
• Projectors with USB input
• Digital photo frames with video function
• Any computer without additional software installation

Simple Structure

AVI's simple architecture provides:

• Reliable playback - fewer decoding errors likely
• Fast seeking - fast-forward works on any device
• Low resource requirements - playback on low-powered processors
• Easy editing - many video editors work with AVI directly

Quality Audio Support

AVI allows uncompressed PCM audio:

• Ideal for archiving music video recordings
• No audio compression artifacts
• Suitable for further editing

AVI Format Limitations

Outdated Technologies

The format has several technical limitations:

• No native H.264/H.265 support - modern codecs work through third-party solutions
• File size limitation - standard AVI is limited to 2 GB (OpenDML extends to 256 GB)
• VBR audio issues - variable bitrate can cause desynchronization
• No HDR support - cannot preserve high dynamic range

Lack of Modern Features

AVI doesn't support:

• Formatted embedded subtitles
• Multiple audio tracks (technically possible but poorly supported)
• Chapter navigation
• Internet streaming playback
• Album cover metadata

When NOT to Convert to AVI

• For modern Smart TVs - they support MP4 and more efficient formats
• For smartphones and tablets - MP4 plays natively
• For archival storage - better to use MKV or source format
• For online publishing - web services prefer MP4 or WebM

Alternative Formats for Compatibility

If AVI doesn't suit your needs, consider alternatives:

MKV (Matroska)

• Modern open container
• Support for all codecs
• Multiple tracks and subtitles
• Growing device compatibility

WMV (Windows Media Video)

• Good compatibility with Windows devices
• Efficient compression
• DRM support (if needed)

MPEG-2 (VOB)

• DVD-Video standard
• Ideal for burning DVD discs
• Maximum compatibility with DVD players

Tips for Optimal Conversion

For DVD Players

• Use Xvid or DivX codec
• Resolution no higher than 720x576 (PAL) or 720x480 (NTSC)
• Video bitrate 1500-2500 Kbps
• Audio MP3 stereo 128-192 Kbps
• Frame rate 25 fps (PAL) or 29.97 fps (NTSC)

For Car Systems

• Check your radio specifications in the manual
• Usually supports up to 720p resolution
• MPEG-4 or Xvid codec preferred
• Bitrate no higher than 4000 Kbps

For Maximum Quality

• Use H.264 codec (if supported)
• Preserve original resolution
• High bitrate (5000+ Kbps)
• Audio AC3 or PCM