Support Afilmory RSS EXIF Spec in Folo

Problem Description

Implement support for the Afilmory RSS EXIF Spec (v1.1) in Folo to parse photography EXIF data in RSS 2.0 feeds. The extension defines a standard for including detailed photographic metadata, enabling RSS readers to access camera settings, lens information, image attributes, location data, and technical parameters.

Specification Overview

Protocol: Afilmory RSS EXIF Extension
Version: 1.1
Identifier: afilmory-rss-exif
Purpose: Standardizes EXIF data in RSS 2.0 feeds for photo gallery websites.
Namespace: exif

Protocol Metadata

• <exif:version>

  • Description: Protocol version number
  • Location: <channel> element
  • Format: Semantic version (e.g., <exif:version>1.1</exif:version>)
  • Required: Yes

• <exif:protocol>

  • Description: Protocol identifier
  • Location: <channel> element
  • Format: String (e.g., <exif:protocol>afilmory-rss-exif</exif:protocol>)
  • Required: Yes

EXIF Tags

Camera Settings (basic)

• <exif:aperture>: Aperture value (e.g., f/1.4)
  • Maps to EXIF FNumber
• <exif:shutterSpeed>: Shutter speed (e.g., 1/250s, 2s)
  • Maps to EXIF ExposureTime
• <exif:iso>: ISO sensitivity (e.g., 1000)
  • Maps to EXIF ISOSpeedRatings
• <exif:exposureCompensation>: Exposure compensation (e.g., +0.7 EV, -1.3 EV)
  • Maps to EXIF ExposureBiasValue

Lens Parameters (lens)

• <exif:focalLength>: Actual focal length (e.g., 50mm)
  • Maps to EXIF FocalLength
• <exif:focalLength35mm>: 35mm equivalent focal length (e.g., 75mm)
  • Maps to EXIF FocalLengthIn35mmFilm
• <exif:lens>: Lens model (e.g., <![CDATA[BS-Optics FX 50mm F1.4]]>)
  • Maps to EXIF LensModel
• <exif:maxAperture>: Maximum lens aperture (e.g., f/1.4)
  • Maps to EXIF MaxApertureValue

Device Information (basic)

• <exif:camera>: Camera make and model (e.g., <![CDATA[FUJIFILM X-T5]]>)
  • Maps to EXIF Make + Model

Image Attributes (basic)

• <exif:imageWidth>: Image width in pixels (e.g., 7728)
  • Maps to actual image width
• <exif:imageHeight>: Image height in pixels (e.g., 5152)
  • Maps to actual image height
• <exif:dateTaken>: Capture timestamp in ISO 8601 (e.g., 2025-06-05T16:12:43.000Z)
  • Maps to EXIF DateTimeOriginal
• <exif:orientation>: Image orientation (1-8) (e.g., 1)
  • Maps to EXIF Orientation

Location Information (location)

• <exif:gpsLatitude>: GPS latitude in decimal degrees (e.g., 39.9042)
  • Maps to EXIF GPSLatitude
• <exif:gpsLongitude>: GPS longitude in decimal degrees (e.g., 116.4074)
  • Maps to EXIF GPSLongitude
• <exif:altitude>: Altitude in meters (e.g., 1200m)
  • Maps to EXIF GPSAltitude
• <exif:location>: Location name (e.g., <![CDATA[Beijing Tiananmen Square]]>)
  • Maps to geocoding or user annotation

Technical Parameters (technical)

• <exif:whiteBalance>: White balance (e.g., Auto)
  • Values: Auto, Daylight, Cloudy, Tungsten, Fluorescent, Flash, Manual
  • Maps to EXIF WhiteBalance
• <exif:meteringMode>: Metering mode (e.g., Matrix)
  • Values: Matrix, Center-weighted, Spot, Multi-spot, Pattern
  • Maps to EXIF MeteringMode
• <exif:flashMode>: Flash mode (e.g., Off)
  • Values: Off, On, Auto, Red-eye, Fill, Slow-sync
  • Maps to EXIF Flash
• <exif:colorSpace>: Color space (e.g., sRGB)
  • Values: sRGB, Adobe RGB, ProPhoto RGB, DCI-P3
  • Maps to EXIF ColorSpace

Advanced Parameters (advanced)

• <exif:exposureProgram>: Exposure program (e.g., Aperture Priority)
  • Values: Manual, Program, Aperture Priority, Shutter Priority, Creative, Action, Portrait, Landscape
  • Maps to EXIF ExposureProgram
• <exif:sceneMode>: Scene mode (e.g., <![CDATA[Portrait]]>)
  • Maps to EXIF SceneCaptureType
• <exif:contrast>: Contrast setting (e.g., Normal)
  • Values: Low, Normal, High
  • Maps to EXIF Contrast
• <exif:saturation>: Saturation setting (e.g., Normal)
  • Values: Low, Normal, High
  • Maps to EXIF Saturation
• <exif:sharpness>: Sharpness setting (e.g., Normal)
  • Values: Soft, Normal, Hard
  • Maps to EXIF Sharpness

Implementation Requirements

• Core Support: Parse <exif:version> and <exif:protocol> in <channel>.
• Basic Fieldset: Prioritize support for basic fields (aperture, shutter speed, ISO, etc.).
• Optional Fieldsets: Support location and advanced fields where applicable.
• Validation: Strictly validate enum values and skip invalid/missing data silently.
• Compatibility: Ensure standard RSS 2.0 readers ignore unrecognized <exif> tags.
• Performance: Preprocess EXIF data to avoid runtime extraction overhead.

Example RSS Feed

https://afilmory.innei.in/feed.xml

Compatibility and Implementation Notes

• Backward Compatibility: Standard RSS 2.0 readers ignore unrecognized <exif> tags.
• Optional Fields: All EXIF tags except <exif:version> and <exif:protocol> are optional. Omit unavailable data instead of using empty tags.
• Data Validation: Validate enum values and skip invalid data silently.
• Performance: Preprocess EXIF data to optimize feed generation.
• Fieldset Support: Implement basic fields first; add location and advanced as needed.

Proposed Implementation

• Add parsing for <exif> namespace in Folo's RSS parser.
• Handle required metadata (<exif:version>, <exif:protocol>).
• Support basic fieldset for core EXIF data.
• Optionally implement location and advanced fieldsets based on use case.
• Validate enum fields against specified values.
• Ensure graceful handling of missing or invalid EXIF data.

Suggested solution

N/A

Alternative

No response

Additional context

No response

Validations

• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.
• This issue is valid

No implementation files or tests are named. Start by locating Folo's RSS parser and inspecting the example feed at https://afilmory.innei.in/feed.xml, then compare its handling with the requested exif namespace. Done means required metadata and prioritized basic fields are parsed, invalid optional values are skipped silently, and RSS 2.0 compatibility is preserved.