Tape format support

[oyvindln]

VHS

• [x] 525-line SP NTSC, PAL-M (Mostly okay - need fine-tuned sub-deemph for HQ)
• [x] 625-line SP PAL (Mostly okay - need fine-tuned sub-deemph for HQ)
• [x] 625-line (PAL) LP (lower speeds work-ish but use SP settings)
• [x] 625 EP/SLP (SP settings, needs some filter work - need separate sub-deemp setting)
• [x] 525-line (NTSC) LP (SP filters/settings - need separate sub-deemp setting)
• [x] 525 EP/SLP (SP filters/settings - need separate sub-deemp setting)
• [ ] 525 VP (super slow speed on certain panasonics, untested)

VHS - PAL-N

• [ ] 625-line SP/LP PAL-N (Not tested, may work-ish with PAL settings, may need a PAL-N setting in ld-chroma-decoder to give correct results)

VHS - SECAM/MESECAM

• [ ] 625-line SP/LP SECAM (Not implemented, luma works since it's the same as PAL, no secam decoder in ld-chroma-decoder)
• [ ] 625-line SP/LP MESECAM (chroma part partially implemented in vhs-decode but no secam decoder in ld-chroma-decoder, luma works since it's the same as PAL)

S-VHS

• [x] SVHS 525-line NTSC (Filtering needs a lot of work, sub-deemphasis filter is tricky)
• [x] SVHS-ET 525-line NTSC (Filtering needs a lot of work, sub-deemphasis filter is tricky)
• [x] SVHS 625-line PAL (Filtering needs a lot of work, sub-deemphasis filter is tricky)
• [x] SVHS-ET 625-line PAL (Filtering needs a lot of work, sub-deemphasis filter is tricky)

U-Matic

• [x] PAL "regular band" (Filtering needs improvement)
• [x] NTSC "regular band" (Filtering needs improvement)
• [ ] PAL hi-band
• [x] PAL SP (hi-band) (Filtering needs improvement, sub-deemphasis needs to be tuned)
• [x] NTSC SP (hi-band) (Filtering needs improvement, sub-deemphasis needs to be tuned)
• [ ] SECAM (SECAM chroma decoder missing, luma may work with PAL settings)

Betamax

• [x] 625-line (PAL) βI - (don't think there is more than one speed for PAL, sub-deemphasis is pretty close)
• [x] 525-line (NTSC) βII - (deemphasis and sub-deemphasis needs to be tuned)
• [ ] 525-line (NTSC) βI (untested, no samples)
• [ ] 525-line (NTSC) βIII (untested, no samples)
• [ ] 625-line (SECAM) βI (untested, no samples)
• [ ] Super Beta
• [ ] ED Beta

Video8, Hi8

• [x] 625-line PAL SP (needs filtering improvements - sub-deemphasis needs to be sorted, tricky to sort it properly)
• [x] 625-line PAL LP (see SP)
• [x] 525-line NTSC SP (needs filtering improvements - sub-deemphasis needs to be sorted, tricky to sort it properly)
• [x] 525-line NTSC LP (see SP)

Other Consumer (Colour-Under) Formats:

• [ ] Philips Video2000
• [x] Philips VCR N1500 (seems okay - could maybe use some fine tuning) (few samples)
• [ ] Philips VCR N1700

Broadcast & Open Reel Formats

• [ ] Shibaden (EIAJ/CCIR)
• [ ] CV
• [x] EIAJ (PAL only need NTSC samples _ works fine though seems specs tend be a bit loose) (few samples)
• [x] 1" Type-C (SMPTE Type-C) 525-line (needs fine-tuning, has "jailbar"-effect) (few samples)
• [x] 1" Type-C (SMPTE Type-C) 625-line ( needs fine-tuning, has "jailbar"-effect) (few samples)
• [ ] 1" Type-B (SMPTE Type-B) 525-line
• [x] 1" Type-B (SMPTE Type-B) 625-line (functions but needs work on head switching) (few samples)
• [ ] 2" Quadruplex (525 / 625 Line)
• [ ] 2" Quadruplex (655-line 48 Field)

Duel Channel Formats

• [ ] W-VHS
• [ ] BetaCam
• [ ] BetaCam SP (Need duel test point PAL/NTSC samples)
• [ ] MI
• [ ] MII

Existing Decoders

• [x] PLX2000 YouTube Video & Github

[etienne-ina]

Just a little comment: Yes, there is a SECAM U-matic, and a SECAM Betamax, and a SECAM VHS. Fortunately, no SECAM V8/Hi8.

Thanks for the outstanding work. Getting pretty good results with CXADC capture of PAL Umatic here (the drop-out compensator is impressive).

If useful, I could provide samples of CXADC captures from low-band U-matic (PAL and SECAM), high-band U-matic / BVU (PAL and SECAM), VHS (SECAM), Betacam (PAL) and maye even SECAM Betamax, Video2000, VCR, and why not 1/2 inch open-reel formats (pre-EIAJ and EIAJ).

[harrypm]

@etienne-ina feel free to add sample data to the community shared drive we have 5TB and growing just read the formatting doc and feel free to expand on it for new 1/2" formats not covered by the list.

[oyvindln]

Awesome. PAL (low-band) U-MATIC could probably use some filter tweaking still, seemed a bit off from what I remember but helpful with more samples.

And samples of all those formats would be awesome.

[etienne-ina]

OK nice, will do. Should I be concerned about the CXADC device being too limited for higher bandwidth formats (such as high-band U-Matic)?

[harrypm]

@etienne-ina 28msps 8-bit can cover most tape formats but you can upgrade it to a 40msps device with a crystal replacement there are lots of little things to improve the abilities of these cards.

[etienne-ina]

@harrypm Thanks. For now, high-band U-Matic through vhs-decode is giving a picture, it's completely off but it's something.

[oyvindln]

Neat, that would be expected as it uses higher frequency carriers for luma (and I think chroma too but don't remember) than "regular band" so need to add a setting for it. I have no idea if 28 msps cxadc will be sufficient to get the higher res variants in good quality but it should at least give something to work with.

[etienne-ina]

I added U-Matic samples to the GDrive, in two folders according to the VTR used for playback. There are:

• 4 PAL U-Matic samples (including one same tape played on 2 different machines)
• 3 PAL BVU samples
• 1 SECAM U-Matic sample

note : "BVU" (as in Broadcast Video U-Matic) is short for High-Band U-Matic.

Don't hesitate if you have prioritary requests for formats / standards you'd like to have more samples from. It will take a bit of time to do all the formats mentioned before (and probably a capture hardware upgrade).

[oyvindln]

We need a better table for this rather than just a checkmark, e.g many formats have a degree of support in the sense that they decode but don't really have correct filtering.

[harrypm]

Tell me how many fields need adding and I'll just mark down a table for it. @oyvindln

[oyvindln]

updated a bit, but could use a better way of presenting it