Martin mode
Martin HQ2
Martin HQ2 is a longer high-quality Martin-family reference mode with the same 320 x 256 raster as HQ1.
Reference onlyMode sample
BBC-style colour test card and app-generated audio
The image is generated locally for this mode's raster. For supported modes, the audio sample is encoded from that image with the SSTV Signal Desk transmitter code, then published as lossless FLAC for static playback.
No app-generated audio sample is published for this reference-only mode because no matching transmitter entry exists in the app code.
Mode spec
| Short name | HQ2 |
|---|---|
| Support status | Reference only |
| Spec status | Reference timing row from the OK2MNM SSTV mode-list PDF. |
| Duration | 112 s |
| Frame | 320 x 256 |
| Data lines | 256 |
| Public VIS | VIS 42 |
| Standard VIS code | 0x2A (42) |
| Extended/N-VIS | No |
| Color model | YCrCb |
| Component sequence | Y-RY-BY |
| Line rate | 137.35 lpm |
| Public timing profile | Mode-list row gives 112 s total duration, 256 scan lines, 320 columns, and 137.35 lpm; line-level porch timing is not part of this catalog row. |
Strengths
- HQ2 has a concrete catalogue row: 112 s, 320 x 256, YCrCb, VIS 42.
- HQ2's Y-RY-BY component order and 137.35 lpm line rate make it useful for comparing airtime, raster, and colour structure against related modes.
Tradeoffs
- HQ2 is not app-supported yet, so the 112 s / 320 x 256 row should be treated as reference data rather than a verified transmit preset.
- HQ2 still needs implementation-grade porch, sync, and pixel timing before an app-generated WAV/FLAC sample can be published with the same confidence as supported modes.
Source notes
OK2MNM SSTV Handbook chapter 5 lists HQ2 as YCrCb, VIS 42, 112 s, 256 lines, 320 columns, 137.35 lpm. Martin high-quality variant found in reference mode catalogs.
- SSTV Handbook Chapter 5: List of SSTV modesSSTV Handbook - accessed 2026-08-24Reference for analog SSTV mode names, VIS codes, durations, line counts, column counts, and line rates.