Convert Image-Based Subtitles to SRT within Plex Server to avoid transcoding

Feature Suggestions
1

Convert Image-Based Subtitles to SRT within Plex Server

“Implement the ability to convert image-based subtitle formats such as VobSub, IDX/SUB-files, and PGS to SRT within the Plex server, eliminating the need for transcoding and ‘burning in’ the subtitles onto the video stream.”

Description:

When importing media from DVDs and Blu-rays, subtitles are often in image formats such as VobSub. However, these formats are not widely supported, posing challenges for seamless subtitle integration.

Advantages:

  1. Enhanced server performance: By eliminating the need for transcoding, this feature reduces the strain on the Plex server, especially when handling UHD content. The server can focus its resources on efficient media streaming rather than video processing.
  2. Maintains media quality: Unlike transcoding, which may result in quality loss, converting image-based subtitles to SRT preserves the original video and audio quality, ensuring an optimal viewing experience for users.
  3. Preserves HDR and Dolby Vision metadata: Transcoding due to unsupported subtitle formats can inadvertently strip luminosity information and metadata associated with HDR and Dolby Vision content. By converting image-based subtitles to SRT, the media retains its original dynamic range, preventing any unintended alterations.
  4. Direct streaming on diverse devices: Streaming devices such as Smart-TVs and UHD devices can seamlessly direct stream media with full quality when paired with SRT subtitles. This eliminates the need for server or device-level transcoding and ensures compatibility with a wider range of devices, including those that may not support certain image-based subtitle formats.

Feasibility:

There are open-source projects available, such as the VobSubOCR and Tesseract OCR engines, which could potentially be leveraged to implement this feature within the Plex server.

VobSubOCR on GitHub
Tesseract OCR on GitHub

By implementing this feature, an enable ‘Subtitle Conversion’ or ‘Subtitle Transcode’ if you will, Plex users can enjoy seamless subtitle integration without the need for transcoding the video, resulting in improved server performance, preserved media quality, and enhanced compatibility with diverse streaming devices.

There are very old threads similar to this but seem to be dead in the water… Hope this will get better traction.