Video 8 capture issues ; Hauppauge, ffmpeg, S-Video and madness

yumyum8 · #1 06-22-2021, 09:08 PM

OS: Debian Linux 10
Capture Unit: Hauppauge WinTV-HVR-1800, Full-height version (Medford)
Capture In/Out: S-Video + Composite "RCA" L/R (red and white) ; separate cables
S-Video Cable: Belkin PureAV 6ft ; Model AV21100-06
Audio Cable: Random Composite "RCA" audio cables
-
ffmpeg: version N-56627-gea1e15fdc4-static https://johnvansickle.com/ffmpeg/
Command Line: ffmpeg -f v4l2 -thread_queue_size 2048 -video_size 720x480 -i /dev/video0 -f alsa -thread_queue_size 2048 -i hw:2 -c:v ffv1 -aspect 4:3 -c:a pcm_s16le Video8_"$(date +%s)".avi

Decyphered the command is:

video format video4linux2, video size is 720x480,
input is video0 (capture card)
-
audio format alsa, input is hardware device 2
video output is ffv1, lossless video codec, force set aspect ratio to 4:3
audio output is WAV 16-bit
Everything into an AVI file (just a container) with current UNIX Timestamp.

Issue 1

Video output seems to be forced progressive. There's like terrible lines and aliasing all over the video footage...

I tried setting -field_order bb, since that's the proper field order you get when doing a DV output for Video8 footage (which gives you 29.97i video, which you can use something like yadif in ffmpeg to turn into proper 59.97fps aka smooth 60fps).
This setting sets a video codec flag but doesn't fix the output video.

Here's an example, sourced from Video8: https://mega.nz/file/eXhi1BQA#1b3kRJ...vHSzmZT7VUP8lQ
I can't tell if the capture card is to blame, the S-Video cable, or the program used.
I should also note that this same terrible quality output was seen when outputting Betacam tapes. Weird aliasing and forced progressive video...

Issue 2

Audio output has some pops, kinda hard to hear but they are there.

Really no idea here. Not sure if it's the card, capture method, buffer, output format, or the cables...
Here's an example, sourced from Betacam: https://mega.nz/file/SWhyVRyQ#ufS1ob...RvkNoay9ojrsIc
I should also note that these pops are heard when outputting Video8 tapes.

---
I really prefer to use Linux, and this is a headless system. I can get a GUI'd linux machine together but it seems excessive for this.
I have no other capture card with S-Video in to test with unfortunately.
If really needed yes I will use Windows but I'd prefer not, I do not agree to their EULA.

Not sure what the heck is going on here but any help is appreciated.
Should I try ffmbc instead?

Thanks everybody, glad to be here!

hodgey · #2 06-23-2021, 05:53 AM

For the first issue, something is causing the fields to be swapped. With e.g swapfields() in avisynth it looks as expected. There is probably some way to do the same with ffmpeg too.

It could be a card setting or driver issue but I don't know. Never experienced that on linux with any capture card, though I have experienced it with a ATI VIVO capture card on a windows XP machine, while other cards on the same machine did not do this. Capturing with ffmpeg should normally work fine.

As for audio, I do know that wrong buffer settings can cause popping and similar effects if there are buffer under/overruns. It should be possible to check for that, I think alsa will log it somewhere if it happens. Does the same thing happen with built-in sound card if it has one?

Also seeing a fair bit of horizontal wiggling, sending the video through e.g a dvd-recorder like the Panasonic DMR-ES10 / ES15 or other device that can help correct for that.

yumyum8 · #3 06-23-2021, 06:56 AM

Quote:

Originally Posted by hodgey

For the first issue, something is causing the fields to be swapped. With e.g swapfields() in avisynth it looks as expected. There is probably some way to do the same with ffmpeg too.

It could be a card setting or driver issue but I don't know. Never experienced that on linux with any capture card, though I have experienced it with a ATI VIVO capture card on a windows XP machine, while other cards on the same machine did not do this. Capturing with ffmpeg should normally work fine.

This is good to know, that swapping the fields results in a proper output. I think honestly though that it's the capture card to be blamed, because it happened across two different video formats.

My only other test would be in a Windows machine but as mentioned I'm not keen on that... drivers for WIndows 7 are probably hard to come by, and I doubt there's any Windows 10 driver. Also not sure how to capture with ffmpeg as easily as on Linux...

The Linux driver is simply the cx23885 firmware for the HVR-1800.
https://www.linuxtv.org/wiki/index.p...-1800#Firmware
Now this firmware is 10 years old... thus maybe some oversight was made somewhere. The card works fine for all other features but only gives issues with video here. Will have to remove the card my linux system at some point and build a Windows testing machine.

Quote:

Originally Posted by hodgey

As for audio, I do know that wrong buffer settings can cause popping and similar effects if there are buffer under/overruns. It should be possible to check for that, I think alsa will log it somewhere if it happens. Does the same thing happen with built-in sound card if it has one?

I will try setting lower buffer values since I set them both to 2048. alsa didn't complain at all, neither codec did, when capturing... so not sure there.

Quote:

Originally Posted by hodgey

Also seeing a fair bit of horizontal wiggling, sending the video through e.g a dvd-recorder like the Panasonic DMR-ES10 / ES15 or other device that can help correct for that.

Is this related to TBC at all? I neglected to mention the unit I'm using, Sony GV-D800. It has a built in TBC that I have active. Otherwise not sure what the DMR model device will do?