Image MIME Reference
DVB-SUB
DVB Subtitle
image/vnd.dvb.subtitle
VS
Macromedia FreeHand Document
image/x-freehand
FreeHand
A complete technical comparison of DVB Subtitle and Macromedia FreeHand Document — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DVB-SUB | FreeHand |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | Yes |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | Yes |
DVB Subtitle
image/vnd.dvb.subtitle
Extension
.sub.sup.ts
Container
MPEG-2 Transport Stream (MPEG-TS) PES Packets
Compression
Lossless (Run-Length Encoding)
Algorithm
RLE (Run-Length Encoding)
Color Depth
2-bit (Indexed), 4-bit (Indexed), 8-bit (Indexed CLUT)
Developed by
DVB Project (ETSI)
Released
1997
Magic Bytes
20
Macromedia FreeHand Document
image/x-freehand
Extension
.fh.fh4.fh5.fh7.fh8.fh9.fh10.fh11.ft11
Container
Proprietary Binary (Aldus Graphic Document)
Compression
Uncompressed / Deflate (in later versions)
Algorithm
NoneDeflate (Optional in later versions)
Color Depth
Vector Data (RGB/CMYK)
Developed by
Altsys / Aldus / Macromedia
Released
1988
Magic Bytes
41 47 44 31 to 41 47 44 34
Browser Support Comparison
| Browser | DVB-SUB | FreeHand |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DVB-SUB
DVB-SUB Strengths
- Guarantees 100% accurate visual representation (fonts, colors, layouts) exactly as intended by the broadcaster
- Effortlessly supports complex character sets (e.g., Arabic, Asian languages) without relying on the client device possessing the necessary fonts
- Supports region-specific dynamic positioning to avoid obscuring important on-screen graphics or burned-in lower thirds
Limitations
- Requires significantly more bandwidth than text-based subtitles
- Inaccessible to screen readers and cannot be indexed by search engines
- Requires OCR (Optical Character Recognition) to translate back into standard text-based web formats
- Zero native support in HTML5 video elements
FreeHand
FreeHand Strengths
- Historically one of the most powerful and intuitive vector editors on the market, praised for multi-page support long before Adobe Illustrator implemented it
- Files are generally compact and self-contained
Limitations
- Completely abandoned proprietary format; Adobe actively blocked native import in modern versions of Illustrator
- No support in modern web browsers; must be converted to SVG
- Versioning fragmentation means parsers must account for wildly different binary structures depending on the specific .fhX extension used
When to choose which format
DVB-SUB
Use DVB-SUB when…
- Digital Television Broadcasts (DVB-T, DVB-S, DVB-C)
- IPTV and OTT Streaming
- Hardware Set-top Boxes
FreeHand
Use FreeHand when…
- Legacy Graphic Design Portfolios
- Historical Desktop Publishing Archival
- Old Corporate Logo Vectors