Software Support > GroovyMAME
Testing Composite Blending from PC – VideoAMP + Antonio Villena VGA → Composite/
Trnzaddict:
I have a question myself.
One of the reasons I lost interest in running CRTEmudriver on my CRT was because Component looked too sharp and many games relying on composite blending did not look right.
At the time a few years ago, I was told that Emudriver will only work through component via a VGA-Component transcoder. Will never work through composite.
With this other transcoder mentioned in this thread, can we get Emudriver to output all timings and resolutions through composite finally? This would open up so many more CRT's to running an Emudriver PC as finding SD sets with component input is becoming harder and harder to find. So many nice sets I find on FB marketplace but they lack component, but have Compsite.
Zebidee:
Hi, you raise a good question.
It is easy to confuse "composite sync" with "composite video". The latter includes sync + video (luma + chroma) signals, all on one cable.
GreenAntz transcoders do RGB (VGA or SCART) to component/YPbPr, not composite video. VideoAMP is not a transcoder.
However, there are some hardware options out there already.
Wakabavideo, who sells on ebay, makes a "RGB SCART to NTSC S-video and composite transcoder/encoder". You would also need to make or buy a VGA-SCART cable similar to mine. I think I've seen a VGA-NTSC version before, but can't find it online right now. Maybe you could ask him directly.
https://www.ebay.com.au/itm/174578156353
An alternative to VGA-SCART cable is an UMSA + standard SCART-SCART (male/male) cable.
Other than that, I could suggest a modded GBS-8200 (+ variants). These are on Aliexpress etc., and I see that some of them come pre-modded. More expensive but also more flexible. Interesting bit of tech, but I've never used one myself. From reports I've heard, it "does the job". That may be good enough.
Cheaper options? Consider adjusting the "sharp" settings of your TV. Models vary, but I find that this generally blurs RGB or component signals somewhat. I usually set it to zero, or close to zero, but perhaps you could try setting it to max for a composite video effect. You may need to access service mode.
If you are OK with a little soldering, component-modding TVs is often easier than RGB modding. I've already done some threads on this.
For all of the above, you would use CRT_emulator or similar (maybe VideoAMP!) first to get the right video modes. That is what they do :notworthy: Then you need the transcoder. The CRT_emulator setup is identical regardless of final colour signal format (as demonstrated by the video above).
I originally listed some things to AVOID, but this post is long enough already :)
--- Quote from: Trnzaddict on September 21, 2025, 10:48:29 am ---I have a question myself.
One of the reasons I lost interest in running CRTEmudriver on my CRT was because Component looked too sharp and many games relying on composite blending did not look right.
At the time a few years ago, I was told that Emudriver will only work through component via a VGA-Component transcoder. Will never work through composite.
With this other transcoder mentioned in this thread, can we get Emudriver to output all timings and resolutions through composite finally? This would open up so many more CRT's to running an Emudriver PC as finding SD sets with component input is becoming harder and harder to find. So many nice sets I find on FB marketplace but they lack component, but have Compsite.
--- End quote ---
Rion:
--- Quote from: Trnzaddict on September 21, 2025, 10:48:29 am ---I have a question myself.
One of the reasons I lost interest in running CRTEmudriver on my CRT was because Component looked too sharp and many games relying on composite blending did not look right.
At the time a few years ago, I was told that Emudriver will only work through component via a VGA-Component transcoder. Will never work through composite.
With this other transcoder mentioned in this thread, can we get Emudriver to output all timings and resolutions through composite finally? This would open up so many more CRT's to running an Emudriver PC as finding SD sets with component input is becoming harder and harder to find. So many nice sets I find on FB marketplace but they lack component, but have Compsite.
--- End quote ---
Short answer: yes - you can get CRT Emudriver timings out over composite or S-Video by adding an RGB→NTSC/PAL encoder (not just an RGB→YPbPr transcoder).
What to use:
1) A composite/S-Video encoder that accepts PC RGBHV
• Two proven options:
- Antonio Villena’s VGA → Composite/S-Video (with sync combiner) - made to take H+V from a PC and internally combine to c-sync.
- wakabavideo’s "RGB VGA → NTSC S-Video & Composite" transcoder/encoder - also accepts RGBHV and includes a sync combiner.
2) Real 15 kHz modes from the PC
• Use CRT Emudriver/Switchres to output 240p/480i (NTSC) or 288p/576i (PAL).
• You will get the classic composite blending artifacts those games expected (dot-crawl, cross-color), which is the goal.
3) SCART-route alternative
• wakabavideo’s SCART → S-Video/Composite encoder also works; feed it with a proper VGA→SCART, VideoAMP, UMSA or a good cable. Functionally the same end result.
4) What not to expect
• RGB→YPbPr component transcoders do not make composite or S-Video.
• Scalers or scan-converters (for example, GBS lines) can work but add processing and do not target native composite artifacts.
Bottom line: If you miss how composite looked (and blended), run 15 kHz from your PC and feed an encoder like Antonio’s or wakabavideo’s VGA unit. That opens up all those nice composite-only TVs you are finding.
Also worth noting for expectations: there is a quality difference between encoder chip families. See the AD723 vs CXA2075 notes in the linked write-up below. For VGA→composite/S-Video, the AD723-based approach often presents a cleaner, more stable result, while CXA2075 can behave a bit differently. Choose the one that suits the look you want.
AD723 vs. CXA2075 – Why the AD723 Can Look Better for VGA → Composite/S-Video
Edit:
Forgot the link to wakabavideo’s - RGB VGA to NTSC S-video and composite transcoder/encoder
It's out of stock right now.
Rion:
--- Quote from: Zebidee on September 21, 2025, 10:36:07 pm ---Hi, you raise a good question.
It is easy to confuse "composite sync" with "composite video". The latter includes sync + video (luma + chroma) signals, all on one cable.
GreenAntz transcoders do RGB (VGA or SCART) to component/YPbPr, not composite video. VideoAMP is not a transcoder.
However, there are some hardware options out there already.
Wakabavideo, who sells on ebay, makes a "RGB SCART to NTSC S-video and composite transcoder/encoder". You would also need to make or buy a VGA-SCART cable similar to mine. I think I've seen a VGA-NTSC version before, but can't find it online right now. Maybe you could ask him directly.
https://www.ebay.com.au/itm/174578156353
An alternative to VGA-SCART cable is an UMSA + standard SCART-SCART (male/male) cable.
Other than that, I could suggest a modded GBS-8200 (+ variants). These are on Aliexpress etc., and I see that some of them come pre-modded. More expensive but also more flexible. Interesting bit of tech, but I've never used one myself. From reports I've heard, it "does the job". That may be good enough.
Cheaper options? Consider adjusting the "sharp" settings of your TV. Models vary, but I find that this generally blurs RGB or component signals somewhat. I usually set it to zero, or close to zero, but perhaps you could try setting it to max for a composite video effect. You may need to access service mode.
If you are OK with a little soldering, component-modding TVs is often easier than RGB modding. I've already done some threads on this.
For all of the above, you would use CRT_emulator or similar (maybe VideoAMP!) first to get the right video modes. That is what they do :notworthy: Then you need the transcoder. The CRT_emulator setup is identical regardless of final colour signal format (as demonstrated by the video above).
I originally listed some things to AVOID, but this post is long enough already :)
--- Quote from: Trnzaddict on September 21, 2025, 10:48:29 am ---I have a question myself.
One of the reasons I lost interest in running CRTEmudriver on my CRT was because Component looked too sharp and many games relying on composite blending did not look right.
At the time a few years ago, I was told that Emudriver will only work through component via a VGA-Component transcoder. Will never work through composite.
With this other transcoder mentioned in this thread, can we get Emudriver to output all timings and resolutions through composite finally? This would open up so many more CRT's to running an Emudriver PC as finding SD sets with component input is becoming harder and harder to find. So many nice sets I find on FB marketplace but they lack component, but have Compsite.
--- End quote ---
--- End quote ---
I agree with your role breakdown - GreenAntz = RGB↔YPbPr transcoder and VideoAMP = amp or switch, not a composite encoder. One useful clarification for readers:
1) "Composite sync" is not "composite video."
C-sync is only the sync line. Composite video is luma + chroma + sync on a single conductor.
2) Two PC-friendly VGA encoders with built-in sync combiners
Both of these accept a regular PC RGBHV signal, combine H+V to c-sync internally, and output S-Video and Composite.
• Antonio Villena’s VGA → Composite/S-Video (sync-combiner variant)
• wakabavideo’s "RGB VGA → NTSC S-Video & Composite" transcoder/encoder
3) SCART-route option
If someone prefers SCART in the chain, wakabavideo’s SCART → S-Video/Composite encoder also works. Feed it with a proper VGA→SCART, VideoAMP, UMSA or a good cable.
4) Timings still matter
Regardless of the encoder, the PC must output true 15 kHz modes (240p/480i NTSC or 288p/576i PAL) via CRT Emudriver or via Linux with the 15khz Kernel patches.
5) Encoder families differ in look
There are quality and behavior differences between encoder chip families. See this write-up for context on AD723 vs CXA2075 and why AD723-type designs can be a better fit for VGA → composite/S-Video in many cases:
AD723 vs CXA2075 - Why the AD723 Can Look Better for VGA → Composite/S-Video
Zebidee:
Thanks Rion for clarifying and adding those links. Silly me forgot to mention Antonio's transcoder! Given it is the original thread topic and all.
Ahhh, Wakaba's NTSC transcoder is out-of-stock, must be why I couldn't find it when searching ebay before.
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