Advanced Options

Frame provides advanced features for power users including stream copy/remux mode, video cropping, trimming, GIF optimization, and hardware encoder-specific options. This guide covers all advanced configuration options.

Stream Copy / Remux Mode

Processing Mode: processingMode: "copy" Stream copy mode copies the video and audio streams directly without re-encoding, changing only the container format.

How Stream Copy Works

Instead of decoding and re-encoding video/audio:

Reads the encoded streams from the source
Copies them directly to the new container
Extremely fast (limited only by disk I/O)
Zero quality loss (bit-for-bit identical)

Benefits

Lightning fast - 10-100x faster than re-encoding
Zero quality loss - Perfect copy of original
Low CPU usage - No encoding overhead
Batch processing - Convert many files quickly

Limitations

Stream copy has many limitations. Frame validates compatibility and will show an error if the operation is not possible.

Cannot be used with:

Changing video codec or audio codec
Changing resolution or frame rate
Applying filters (crop, rotate, flip, scale)
Burn-in subtitles
Audio normalization or volume adjustment
Hardware decode acceleration
GIF output (GIF is a video-only container)

Can be used with:

Changing container format (remuxing)
Trimming video (start/end time)
Selecting specific audio/subtitle tracks
Metadata changes (preserve/clean/replace)

Codec Compatibility

The source video/audio codecs must be compatible with the target container. Example - Valid Stream Copy:

Source: video.mkv (H.264 video, AAC audio)
Target: video.mp4 (MP4 container)
✓ H.264 is compatible with MP4
✓ AAC is compatible with MP4
Result: Fast remux succeeds

Example - Invalid Stream Copy:

Source: video.mkv (VP9 video, Opus audio)
Target: video.mp4 (MP4 container)
✗ VP9 is not compatible with MP4
✗ Opus is not compatible with MP4
Result: Frame shows error, use re-encode mode

Stream Copy Configuration

{
  "processingMode": "copy",
  "container": "mp4"
}

Use Cases

Container Remuxing

Changing Container Format

Convert MKV to MP4 without re-encoding:

{
  "processingMode": "copy",
  "container": "mp4"
}

Speed: Seconds instead of minutes/hoursUse when:

Need MP4 for device compatibility
MKV to MP4 for streaming
Changing format without quality loss

Extract Audio Track

Audio Extraction

Extract audio from video without re-encoding:

{
  "processingMode": "copy",
  "container": "m4a",
  "selectedAudioTracks": [0]
}

Speed: Very fast audio extractionUse when:

Extracting music from music videos
Getting audio for editing
Creating audio-only files

Cut/Trim Without Re-encoding

Fast Trimming

Cut video segment without quality loss:

{
  "processingMode": "copy",
  "container": "mp4",
  "startTime": "00:01:30",
  "endTime": "00:05:00"
}

Note: Cuts may not be frame-accurate due to keyframe limitations.Use when:

Quick rough cuts
Removing intro/outro
Extracting segments

FFmpeg Implementation

-c copy

Frame automatically validates stream compatibility before attempting copy mode.

Video Cropping

Crop video to a specific region, removing unwanted areas.

Crop Configuration

interface CropSettings {
  enabled: boolean;
  x: number;          // Left edge position
  y: number;          // Top edge position
  width: number;      // Crop width
  height: number;     // Crop height
  sourceWidth?: number;
  sourceHeight?: number;
  aspectRatio?: string | null;
}

How Cropping Works

Define a rectangle within the source video
Only that rectangle is kept in the output
Applied before scaling/resolution changes
Can maintain aspect ratio constraints

Example Configuration

Crop to center 1920x1080 from 4K source:

{
  "crop": {
    "enabled": true,
    "x": 960,
    "y": 540,
    "width": 1920,
    "height": 1080
  }
}

FFmpeg Implementation

crop=1920:1080:960:540

Format: crop=width:height:x:y

Use Cases

Remove Black Bars

Removing Letterboxing

Remove black bars from 16:9 content in 4:3 frame:Source: 1440x1080 (4:3 frame with 16:9 content)Crop to 16:9:

{
  "crop": {
    "enabled": true,
    "x": 0,
    "y": 135,
    "width": 1440,
    "height": 810
  }
}

Social Media Aspect Ratios

Crop to Platform Requirements

TikTok/Reels (9:16 portrait) from 16:9 landscape:Source: 1920x1080 (16:9)Crop to 9:16 centered:

{
  "crop": {
    "enabled": true,
    "x": 420,
    "y": 0,
    "width": 1080,
    "height": 1920
  }
}

Instagram Square (1:1) from 16:9:

{
  "crop": {
    "enabled": true,
    "x": 420,
    "y": 0,
    "width": 1080,
    "height": 1080
  }
}

Remove Watermarks/Logos

Cropping Out Overlays

Remove logo from bottom-right corner:Source: 1920x1080 with logo at bottom-rightCrop to remove:

{
  "crop": {
    "enabled": true,
    "x": 0,
    "y": 0,
    "width": 1800,
    "height": 1000
  }
}

Then scale back to 1920x1080 if needed.

Cropping is applied before scaling. The cropped dimensions become the input for any resolution changes.

Trim / Cut Video

Extract a specific time range from video.

Time Range Configuration

{
  "startTime": "00:01:30",
  "endTime": "00:05:00"
}

Time Format

Frame supports multiple time formats:

HH:MM:SS - "00:01:30" (1 minute 30 seconds)
MM:SS - "01:30" (1 minute 30 seconds)
Seconds - "90" (90 seconds)
Fractional - "90.5" (90.5 seconds)

How Trimming Works

With startTime only:

Start encoding from specified time
Continue to end of video

With endTime only:

Start from beginning
End at specified time

With both:

Extract segment between start and end
Duration = endTime - startTime

FFmpeg Implementation

Start time (before input):

-ss 00:01:30 -i input.mp4

End time (duration calculation):

-t 00:03:30  # Duration from start

-to 00:05:00  # Absolute end time

Frame’s Implementation

From source code (args.rs:148-178):

if let Some(start) = &config.start_time {
    args.push("-ss".to_string());
    args.push(start.clone());
}

args.push("-i".to_string());
args.push(input.to_string());

if let Some(end_str) = &config.end_time {
    if let Some(start_str) = &config.start_time {
        // Calculate duration if both start and end specified
        let duration = end_t - start_t;
        args.push("-t".to_string());
        args.push(format!("{:.3}", duration));
    } else {
        args.push("-to".to_string());
        args.push(end_str.clone());
    }
}

Use Cases

Remove Intro/Outro

Removing Unwanted Sections

Remove first 10 seconds:

{
  "startTime": "00:00:10"
}

Remove last 5 seconds (from 10-minute video):

{
  "endTime": "00:09:55"
}

Extract Highlights

Extracting Specific Segments

Extract 30-second clip starting at 2:15:

{
  "startTime": "00:02:15",
  "endTime": "00:02:45"
}

Extract middle section (1min to 5min):

{
  "startTime": "00:01:00",
  "endTime": "00:05:00"
}

Trimming works in both re-encode and stream copy modes. In stream copy mode, cuts may not be frame-accurate due to keyframe positions.

GIF-Specific Options

When outputting to GIF container, Frame exposes advanced GIF optimization options.

GIF Configuration

{
  "container": "gif",
  "gifColors": 256,
  "gifDither": "sierra2_4a",
  "gifLoop": 0
}

GIF Color Palette

Setting: gifColors Range: 2-256 colors Default: 256

How It Works

GIF uses an indexed color palette. Fewer colors = smaller file size but lower quality. Color Count Guidelines:

256 colors - Maximum quality (default)
128 colors - Good quality, smaller files (Frame’s “GIF Web Small” preset)
64 colors - Acceptable for simple graphics
32 colors - Low quality, very small files
16 colors - Very limited, dithering artifacts
2-8 colors - Only for very simple graphics

Configuration

{
  "gifColors": 128
}

File Size Impact

Reducing colors can reduce file size by 20-50% depending on content complexity.

GIF Dithering

Setting: gifDither Options: "none", "bayer", "floyd_steinberg", "sierra2_4a" Default: "sierra2_4a"

Dithering Algorithms

None
Bayer
Floyd-Steinberg
Sierra2_4a

No Dithering

Value: "none"

Characteristics

No dithering applied
Posterization in gradients
Smallest file size
Clean, sharp edges

Use Cases

Simple graphics with solid colors
Pixel art
Logos and icons
When file size is critical

Example

{
  "gifDither": "none",
  "gifColors": 64
}

Bayer Dithering

Value: "bayer"

Characteristics

Ordered dithering pattern
Visible grid pattern
Fast processing
Moderate file size

Use Cases

Retro/vintage aesthetics
Artistic effects
Fast processing needed

Example

{
  "gifDither": "bayer",
  "gifColors": 128
}

Floyd-Steinberg Dithering

Value: "floyd_steinberg"

Characteristics

Error diffusion algorithm
Natural-looking dithering
Good for photographs
Larger file size than Bayer

Use Cases

Photographic GIFs
High-quality appearance
Natural color transitions

Example

{
  "gifDither": "floyd_steinberg",
  "gifColors": 256
}

Frame’s “GIF High Quality” preset uses Floyd-Steinberg with 256 colors for best photographic quality.

Sierra2_4a Dithering

Value: "sierra2_4a"

Characteristics

Error diffusion variant
Balanced quality and file size
Less visible patterns than Bayer
Slightly smaller than Floyd-Steinberg

Use Cases

Default choice - good balance
Web GIFs
General-purpose animations
Most video content

Example

{
  "gifDither": "sierra2_4a",
  "gifColors": 128
}

This is Frame’s default dithering algorithm, used in all GIF presets except “GIF High Quality”.

GIF Loop Count

Setting: gifLoop Range: 0-65535 Default: 0 (infinite loop)

Loop Options

0 - Loop forever (default, recommended)
1 - Play once, no loop
2+ - Loop specific number of times

Configuration

Infinite loop:

{
  "gifLoop": 0
}

Play once:

{
  "gifLoop": 1
}

Loop 5 times:

{
  "gifLoop": 5
}

Most platforms and viewers expect GIFs to loop infinitely. Use gifLoop: 0 for standard behavior.

GIF Optimization Examples

High Quality GIF

Maximum Quality

Frame’s “GIF High Quality” preset:

{
  "container": "gif",
  "gifColors": 256,
  "gifDither": "floyd_steinberg",
  "gifLoop": 0,
  "resolution": "720p",
  "fps": "15"
}

Best for:

Photographic content
High-quality requirements
Portfolio work

Small Web GIF

Optimized for File Size

Frame’s “GIF Web Small” preset:

{
  "container": "gif",
  "gifColors": 128,
  "gifDither": "sierra2_4a",
  "gifLoop": 0,
  "customWidth": "640",
  "customHeight": "360",
  "fps": "12"
}

Best for:

Web embedding
Fast loading
Social media
Reduced bandwidth

Pixel Art GIF

Sharp, Clean Pixel Art

{
  "container": "gif",
  "gifColors": 64,
  "gifDither": "none",
  "gifLoop": 0,
  "scalingAlgorithm": "nearest"
}

Best for:

Pixel art animations
Retro games
Simple graphics

FFmpeg GIF Filter Implementation

From source code (args.rs:326-343):

fn build_gif_filter_complex(config: &ConversionConfig) -> String {
    let colors = config.gif_colors.clamp(2, 256);
    let dither = normalize_gif_dither(&config.gif_dither);
    
    format!(
        "[0:v:0]{chain};[gif_palette_src]palettegen=max_colors={colors}:stats_mode=single[gif_palette];[gif_src][gif_palette]paletteuse=dither={dither}:new=1[gif_out]"
    )
}

Frame uses FFmpeg’s two-pass palette generation for optimal GIF quality.

Hardware Encoder Advanced Options

Frame exposes hardware-specific options for fine-tuning encoding.

NVENC Adaptive Quantization

See Hardware Acceleration - NVENC Advanced Options for details: Spatial AQ:

{
  "nvencSpatialAq": true
}

Temporal AQ:

{
  "nvencTemporalAq": true
}

VideoToolbox Software Fallback

See Hardware Acceleration - VideoToolbox Advanced Options for details: Allow software fallback:

{
  "videotoolboxAllowSw": true
}

Get Started

Features

Guides

Development

​Advanced Options

​Stream Copy / Remux Mode

​How Stream Copy Works

​Benefits

​Limitations

​Codec Compatibility

​Stream Copy Configuration

​Use Cases

​Changing Container Format

​Audio Extraction

​Fast Trimming

​FFmpeg Implementation

​Video Cropping

​Crop Configuration

​How Cropping Works

​Example Configuration

​FFmpeg Implementation

​Use Cases

​Removing Letterboxing

​Crop to Platform Requirements

​Cropping Out Overlays

​Trim / Cut Video

​Time Range Configuration

​Time Format

​How Trimming Works

​FFmpeg Implementation

​Frame’s Implementation

​Use Cases

​Removing Unwanted Sections

​Extracting Specific Segments

​GIF-Specific Options

​GIF Configuration

​GIF Color Palette

​How It Works

​Configuration

​File Size Impact

​GIF Dithering

​Dithering Algorithms

​No Dithering

​Characteristics

​Use Cases

​Example

​Bayer Dithering

​Characteristics

​Use Cases

​Example

​Floyd-Steinberg Dithering

​Characteristics

​Use Cases

​Example

​Sierra2_4a Dithering

​Characteristics

​Use Cases

​Example

​GIF Loop Count

​Loop Options

​Configuration

​GIF Optimization Examples

​Maximum Quality

​Optimized for File Size

​Sharp, Clean Pixel Art

​FFmpeg GIF Filter Implementation

​Hardware Encoder Advanced Options

​NVENC Adaptive Quantization

​VideoToolbox Software Fallback

​See Also

Build docs developers (and LLMs) love

Advanced Options

Stream Copy / Remux Mode

How Stream Copy Works

Benefits

Limitations

Codec Compatibility

Stream Copy Configuration

Use Cases

Changing Container Format

Audio Extraction

Fast Trimming

FFmpeg Implementation

Video Cropping

Crop Configuration

How Cropping Works

Example Configuration

FFmpeg Implementation

Use Cases

Removing Letterboxing

Crop to Platform Requirements

Cropping Out Overlays

Trim / Cut Video

Time Range Configuration

Time Format

How Trimming Works

FFmpeg Implementation

Frame’s Implementation

Use Cases

Removing Unwanted Sections

Extracting Specific Segments

GIF-Specific Options

GIF Configuration

GIF Color Palette

How It Works

Configuration

File Size Impact

GIF Dithering

Dithering Algorithms

No Dithering

Characteristics

Use Cases

Example

Bayer Dithering

Characteristics

Use Cases

Example

Floyd-Steinberg Dithering

Characteristics

Use Cases

Example

Sierra2_4a Dithering

Characteristics

Use Cases

Example

GIF Loop Count

Loop Options

Configuration

GIF Optimization Examples

Maximum Quality

Optimized for File Size

Sharp, Clean Pixel Art

FFmpeg GIF Filter Implementation

Hardware Encoder Advanced Options

NVENC Adaptive Quantization

VideoToolbox Software Fallback

See Also