File Formats

File Formats

Comprehensive reference for all supported input and output formats in DeepTalk. This guide covers audio/video input formats, export options, and optimization recommendations.

Supported Input Formats

Audio Formats

Primary Audio Formats:

  • MP3 (.mp3)
    • Compatibility: Universal support across all platforms
    • Quality: Good compression with acceptable quality loss
    • Recommended for: General-purpose audio files, podcasts, meetings
    • File size: Efficient compression, typically 1MB per minute
    • Notes: Most widely supported format
  • WAV (.wav)
    • Compatibility: Universal uncompressed format
    • Quality: Lossless, highest quality
    • Recommended for: High-quality recordings, professional audio
    • File size: Large files, typically 10MB per minute
    • Notes: Best quality for transcription accuracy
  • M4A (.m4a)
    • Compatibility: Apple format, widely supported
    • Quality: Good compression with high quality
    • Recommended for: Apple device recordings, AAC encoded content
    • File size: Efficient compression, similar to MP3
    • Notes: Default format for Apple devices

Additional Audio Formats:

  • FLAC (.flac)
    • Quality: Lossless compression
    • File size: Smaller than WAV, larger than MP3
    • Use case: Archival quality with compression
  • OGG (.ogg, .oga)
    • Quality: Open source, good compression
    • File size: Similar to MP3
    • Use case: Open source projects, Linux environments
  • AAC (.aac)
    • Quality: Advanced Audio Coding, efficient compression
    • File size: Smaller than MP3 with similar quality
    • Use case: Streaming, mobile applications
  • WMA (.wma)
    • Quality: Windows Media Audio format
    • File size: Variable compression
    • Use case: Windows-specific audio files

Video Formats

Primary Video Formats:

  • MP4 (.mp4)
    • Compatibility: Universal video format
    • Audio extraction: Automatic audio track extraction
    • Recommended for: Video meetings, presentations, interviews
    • File size: Efficient compression for video content
    • Notes: Most common video format, excellent support
  • MOV (.mov)
    • Compatibility: Apple QuickTime format, widely supported
    • Audio extraction: High-quality audio extraction
    • Recommended for: Apple device recordings, professional video
    • File size: Variable based on compression settings
    • Notes: Common for Apple device recordings

Additional Video Formats:

  • AVI (.avi)
    • Compatibility: Windows video format, widely supported
    • Audio extraction: Multiple audio track support
    • Use case: Windows-based video files
  • MKV (.mkv)
    • Compatibility: Matroska format, open source
    • Audio extraction: Supports multiple audio tracks and languages
    • Use case: High-quality video with multiple audio options
  • WebM (.webm)
    • Compatibility: Web-optimized format
    • Audio extraction: Web-standard audio extraction
    • Use case: Web-based video recordings
  • FLV (.flv)
    • Compatibility: Flash video format
    • Audio extraction: Legacy format support
    • Use case: Older web video content

File Size and Duration Limits

Recommended Limits:

  • Maximum file size: 2GB per file
  • Optimal file size: Under 500MB for best performance
  • Maximum duration: No specific limit, but longer files take more time
  • Optimal duration: 2-3 hours for interactive processing

Performance Considerations:

File Size    Processing Time    Memory Usage    Recommendation
─────────    ───────────────    ────────────    ──────────────
< 50MB       1-3 minutes        < 1GB RAM      Optimal
50-200MB     3-10 minutes       1-2GB RAM      Good
200-500MB    10-30 minutes      2-4GB RAM      Acceptable
500MB-1GB    30-60 minutes      4-6GB RAM      Slow but manageable
> 1GB        60+ minutes        6+ GB RAM      Consider splitting

File Splitting Recommendations:

  • Large files: Split files over 1GB into smaller segments
  • Long recordings: Break recordings longer than 3 hours into parts
  • Multiple topics: Split by topic or speaker changes for better organization
  • Processing efficiency: Smaller files process faster and use less memory

Export Formats

Document Formats

PDF Export:

  • Extension: .pdf
  • Use case: Professional reports, sharing, archival
  • Features:
    • Formatted layout with headers and footers
    • Table of contents for long documents
    • Searchable text content
    • Print-optimized formatting
  • Customization: Custom templates, branding, layout options
  • Best for: Executive summaries, meeting minutes, formal reports

Microsoft Word (.docx):

  • Extension: .docx
  • Use case: Collaborative editing, further customization
  • Features:
    • Fully editable document format
    • Style preservation and formatting
    • Comment and revision tracking support
    • Template-based generation
  • Customization: Custom styles, corporate templates
  • Best for: Documents requiring further editing or collaboration

Rich Text Format (.rtf):

  • Extension: .rtf
  • Use case: Cross-platform document sharing
  • Features:
    • Universal word processor compatibility
    • Basic formatting preservation
    • Smaller file size than Word format
    • Cross-platform compatibility
  • Best for: Simple formatted documents, legacy system compatibility

Text Formats

Plain Text (.txt):

  • Extension: .txt
  • Use case: Simple text sharing, data processing
  • Features:
    • No formatting, pure text content
    • Universal compatibility
    • Smallest file size
    • Easy to process programmatically
  • Best for: Raw transcription text, data analysis, simple sharing

Markdown (.md):

  • Extension: .md
  • Use case: Documentation, web publishing
  • Features:
    • Structured text with simple markup
    • Version control friendly
    • Easy conversion to HTML and other formats
    • Widely supported by documentation platforms
  • Best for: Technical documentation, GitHub integration, web publishing

HTML Export:

  • Extension: .html
  • Use case: Web publishing, email sharing
  • Features:
    • Web-ready format with styling
    • Interactive elements and links
    • Custom CSS styling support
    • Accessible web format
  • Best for: Web publishing, email newsletters, accessible sharing

Data Formats

JSON Export:

  • Extension: .json
  • Use case: API integration, data analysis
  • Features:
    • Machine-readable structured data
    • Complete metadata preservation
    • Hierarchical data organization
    • Programming language friendly
  • Structure: 
    {
  "transcript": {
    "id": "unique-identifier",
    "title": "Meeting Title",
    "duration": 3600,
    "speakers": [...],
    "segments": [...],
    "analysis": {...}
  }
}
  • Best for: Custom integrations, data processing, backup

CSV Export:

  • Extension: .csv
  • Use case: Spreadsheet analysis, database import
  • Features:
    • Tabular data format
    • Spreadsheet application compatible
    • Database import ready
    • Simple data analysis
  • Structure: 
    timestamp,speaker,text,confidence
00:00:00,Speaker 1,"Welcome to the meeting",0.95
00:00:05,Speaker 2,"Thank you for having me",0.92
  • Best for: Data analysis, spreadsheet import, reporting

XML Export:

  • Extension: .xml
  • Use case: Enterprise integration, structured data exchange
  • Features:
    • Structured markup format
    • Schema validation support
    • Enterprise system compatibility
    • Hierarchical data representation
  • Best for: Enterprise integration, data transformation, validation

Specialized Formats

Subtitle Formats:

  • SRT (.srt): Standard subtitle format
  • VTT (.vtt): Web Video Text Tracks format
  • ASS/SSA (.ass/.ssa): Advanced subtitle formats
  • Use case: Video captioning, accessibility, media production

Audio Export:

  • Extract audio segments: Export specific portions as audio files
  • Speaker isolation: Export individual speaker audio tracks
  • Time-coded audio: Audio with embedded timestamp information
  • Use case: Audio analysis, speaker training, quality review

Custom Templates:

  • Template-based export: Use custom document templates
  • Branded formats: Corporate branding and styling
  • Specialized layouts: Industry-specific document formats
  • Use case: Corporate compliance, standardized reporting

Format Selection Guidelines

Choosing Input Formats

For Best Transcription Quality:

  1. WAV or FLAC: Lossless formats for highest accuracy
  2. High bitrate MP3: 320kbps or higher for good quality
  3. Uncompressed audio: When file size is not a concern
  4. Clear recording: Quality matters more than format

For Processing Efficiency:

  1. MP3 or M4A: Good balance of quality and file size
  2. Moderate compression: Avoid over-compressed files
  3. Consistent format: Use same format across project
  4. Optimized recording: Record at appropriate levels

For Compatibility:

  1. MP3: Universal compatibility across all systems
  2. MP4: For video content with audio extraction
  3. Standard bitrates: Use common compression settings
  4. Verified formats: Test format compatibility before large uploads

Choosing Export Formats

For Professional Sharing:

  • PDF: Executive reports, formal documentation
  • Word: Collaborative documents, editable reports
  • HTML: Web sharing, accessible documentation

For Technical Use:

  • JSON: API integration, data processing
  • CSV: Data analysis, spreadsheet import
  • XML: Enterprise systems, structured data

For Simple Distribution:

  • Text: Raw content, simple sharing
  • Markdown: Technical documentation, version control
  • RTF: Cross-platform compatibility

Quality Optimization

Input Quality Guidelines

Audio Recording Best Practices:

  • Sample rate: 44.1kHz or higher
  • Bit depth: 16-bit minimum, 24-bit preferred
  • Format: Uncompressed or lossless when possible
  • Recording levels: Avoid clipping, maintain consistent levels
  • Environment: Minimize background noise and echo

File Preparation:

  • Normalization: Consistent audio levels
  • Noise reduction: Remove background noise if possible
  • Format conversion: Convert to optimal format before upload
  • File naming: Use descriptive, consistent naming conventions

Quality Indicators:

  • File size: Larger files often indicate better quality
  • Duration vs. size: Check if compression is appropriate
  • Audio clarity: Test playback quality before upload
  • Metadata: Include relevant information for processing

Export Quality Settings

Document Export Quality:

  • PDF resolution: 300 DPI for print, 150 DPI for screen
  • Image compression: Balance quality and file size
  • Font embedding: Ensure consistent appearance
  • Layout optimization: Optimize for intended use

Data Export Quality:

  • Character encoding: UTF-8 for international character support
  • Data validation: Verify data integrity after export
  • Format compliance: Ensure standards compliance
  • Metadata preservation: Include relevant metadata

Troubleshooting Format Issues

Common Format Problems

Unsupported Format Errors:

Error: Unsupported file format

Solutions:

  • Verify format is in supported list above
  • Convert file to supported format
  • Check file extension matches actual format
  • Test with sample file of known format

Corrupted File Errors:

Error: Unable to read file

Solutions:

  • Test file in media player first
  • Re-export from original source
  • Use file repair tools if available
  • Try different compression settings

Large File Issues:

Error: File too large to process

Solutions:

  • Split file into smaller segments
  • Compress file to reduce size
  • Use cloud processing if available
  • Upgrade system resources

Format Conversion Tools

Free Conversion Tools:

  • FFmpeg: Command-line tool for audio/video conversion
  • Audacity: Free audio editing and conversion
  • VLC Media Player: Simple format conversion
  • Online converters: Web-based conversion services

FFmpeg Conversion Examples:

# Convert various formats to MP3
ffmpeg -i input.wav output.mp3
ffmpeg -i input.m4a output.mp3
ffmpeg -i input.flac output.mp3

# Extract audio from video
ffmpeg -i input.mp4 -vn -acodec mp3 output.mp3
ffmpeg -i input.mov -vn -acodec wav output.wav

# Compress large files
ffmpeg -i input.wav -ab 128k output.mp3
ffmpeg -i input.wav -ar 44100 -ab 192k output.mp3

Quality vs. Size Optimization:

# High quality (larger files)
ffmpeg -i input.wav -ab 320k output.mp3

# Balanced quality (medium files)
ffmpeg -i input.wav -ab 192k output.mp3

# Small size (lower quality)
ffmpeg -i input.wav -ab 128k output.mp3

Platform-Specific Considerations

Windows:

  • Media Foundation: Built-in support for common formats
  • DirectShow: Legacy support for additional formats
  • Windows Media Player: Test compatibility
  • File associations: Verify correct program associations

macOS:

  • Core Audio: Native audio format support
  • QuickTime: Video and audio format support
  • iTunes/Music: Audio format compatibility testing
  • File type associations: Check default applications

Linux:

  • GStreamer: Multimedia framework for format support
  • FFmpeg: Primary tool for format conversion
  • Package management: Install codec packages as needed
  • Audio server: Ensure proper audio system configuration

Format Standards and Specifications

Audio Format Specifications

MP3 (MPEG-1/2 Audio Layer 3):

  • Standard: ISO/IEC 11172-3, ISO/IEC 13818-3
  • Compression: Lossy compression
  • Bitrates: 32-320 kbps
  • Sample rates: 16, 22.05, 24, 32, 44.1, 48 kHz
  • Channels: Mono, stereo

WAV (Waveform Audio File Format):

  • Standard: Microsoft/IBM specification
  • Compression: Uncompressed PCM
  • Bit depth: 8, 16, 24, 32 bit
  • Sample rates: 8-192 kHz
  • Channels: Mono to multi-channel

AAC (Advanced Audio Coding):

  • Standard: ISO/IEC 13818-7, ISO/IEC 14496-3
  • Compression: Lossy compression
  • Bitrates: 8-529 kbps
  • Sample rates: 8-96 kHz
  • Channels: Mono to 48 channels

Export Format Standards

PDF Standards:

  • PDF/A: Archival format for long-term preservation
  • PDF/UA: Universal accessibility standard
  • PDF 1.4-2.0: Version compatibility
  • Searchability: Text layer preservation

Document Standards:

  • DOCX: Office Open XML format
  • RTF: Rich Text Format specification
  • HTML5: Modern web standard
  • Markdown: CommonMark specification

Data Format Standards:

  • JSON: RFC 7159 specification
  • CSV: RFC 4180 specification
  • XML: W3C XML 1.0 specification
  • UTF-8: Unicode character encoding

Quick format check: If you’re unsure about a file format, try uploading a small sample first, or use the file command on Linux/macOS to identify the format: file yourfile.ext