Dropped frames, ES15, and audio sync?

[ThumperStrauss]

I ran the same 1 hour VHS video recording to my ATI 9600XT using six methods, to test how SVHS line TBC, ES-15, and DVK compare to one another when it comes to reducing dropped/inserted frames when capturing in VirtualDub 1.9.11. (I used the exact Timing settings in Sanlyn's guide, with the exception of the LS's suggestion to select Drop frames and Insert null frame.)

In short, with ES-15 and/or DVK in the workflow, dropped/inserted was 0/2 at the low end and 0/5 at the high end. So, basically an insignificant difference. The ES-15 and DVK both helped prevent dropped/inserted frame.

Without the ES-15 or DVK in the workflow, I got about 19/50 dropped/inserted with my JVC SVHS with Line TBC turned on, and in another test with the Line TBC turned off. In other words, in this test on this tape the Line TBC creating a more stable image didn't reduce the number of dropped frames, even a little bit.

1. For the videos with the 19/50 dropped/inserted, I was expecting to find the audio and video out of sync. But it was not out of sync, even at the end of the hour. That was a nice surprise, but unexpected.

2. For the videos where I used the ES-15 in the workflow, the audio was ahead, right from the first frame and all the way to the end of the video—even though there were almost no dropped framed. Then I figured it out. I didn't pass the audio through the ES-15. Instead, I sent it from the SVHS player directly to the Turtle Beach Santa Cruz TB400 sound card. So my guess is that because it didn't need to pass through the ES15, it got to the sound card faster. Is the best practice when using the ES-15 to pass the audio through it as well?

[Gary34]

https://www.digitalfaq.com/forum/vcr...-dmr-es10.html Did you get the timing settings for your card? There’re some hacks for the ATI cards in the guide. https://www.digitalfaq.com/forum/vid...der-hacks.html

[timtape]

Quote:

Originally Posted by ThumperStrauss

2. For the videos where I used the ES-15 in the workflow, the audio was ahead, right from the first frame and all the way to the end of the video—even though there were almost no dropped framed. Then I figured it out. I didn't pass the audio through the ES-15. Instead, I sent it from the SVHS player directly to the Turtle Beach Santa Cruz TB400 sound card. So my guess is that because it didn't need to pass through the ES15, it got to the sound card faster. Is the best practice when using the ES-15 to pass the audio through it as well?

Yes, or if you forget to, in the editing timeline delay the audio by the number of frames it became advanced. That can save having to reingest many tapes.

[mrmuy97]

Quote:

Originally Posted by ThumperStrauss

Without the ES-15 or DVK in the workflow, I got about 19/50 dropped/inserted with my JVC SVHS with Line TBC turned on, and in another test with the Line TBC turned off. In other words, in this test on this tape the Line TBC creating a more stable image didn't reduce the number of dropped frames, even a little bit.

In this test, did you expect the line TBC off/on to have an effect on frame synchronization for your capture device?

Quote:

Originally Posted by ThumperStrauss

1. For the videos with the 19/50 dropped/inserted, I was expecting to find the audio and video out of sync. But it was not out of sync, even at the end of the hour. That was a nice surprise, but unexpected.

With video and audio output from the deck feeding directly to your video and audio capture devices for realtime capture with no processing in between, why did you expect them to be out of sync?

Quote:

Originally Posted by ThumperStrauss

2. For the videos where I used the ES-15 in the workflow, the audio was ahead, right from the first frame and all the way to the end of the video—even though there were almost no dropped frames. Then I figured it out. I didn't pass the audio through the ES-15. Instead, I sent it from the SVHS player directly to the [...] sound card. So my guess is that because it didn't need to pass through the ES15, it got to the sound card faster.

Correct, in that test your video was being delayed for processing before getting to the capture device, while the audio was captured with no delay.

Quote:

Originally Posted by ThumperStrauss

Is the best practice when using the ES-15 to pass the audio through it as well?

Per timtape's reply, either pass the audio through, or bypass the ES15 and delay the audio to match the video. I'm not familiar with how the ES15 handles audio when passed through, whether it's transparent or processed at all to sync up with the video output. I imagine all the info is out there in the main ES10/15 passthrough threads like this one:

https://forum.videohelp.com/threads/...15-DMR-ES25%29

[lordsmurf]

Quote:

Originally Posted by ThumperStrauss

the Line TBC creating a more stable image didn't reduce the number of dropped frames, even a little bit.

As expected. "frame timing" is really "temporal timing", and line TBC has no temporal corrections.

Quote:

1. For the videos with the 19/50 dropped/inserted, I was expecting to find the audio and video out of sync. But it was not out of sync, even at the end of the hour. That was a nice surprise, but unexpected.

This may depends on settings. In general, drops cause audio desync.

Quote:

2. For the videos where I used the ES-15 in the workflow, the audio was ahead, right from the first frame and all the way to the end of the video—even though there were almost no dropped framed. Then I figured it out. I didn't pass the audio through the ES-15. Instead, I sent it from the SVHS player directly to the Turtle Beach Santa Cruz TB400 sound card. So my guess is that because it didn't need to pass through the ES15, it got to the sound card faster. Is the best practice when using the ES-15 to pass the audio through it as well?

Correct. The ES10/15 has a significant delay, likely due to all the harsh processing (as the NR is always on, and "off" is really just a low setting). Audio bypass will result in at least 200ms offset, more like 500ms (full half second).

Quote:

Originally Posted by mrmuy97

the main ES10/15 passthrough threads like this one:

Be aware that the VH thread has a lot of misinformation, due to the VH peanut gallery chiming in with BS. I probably need to create something more reliable here.

Quote:

Originally Posted by ThumperStrauss

...

Something not mentioned here, but should be, is that the combination of ES10/15 + modded DVK can create a 99%+ actual TBC, though with image artifacts and noise. Not ES10/15 alone, not DVK alone. The ES10/15 is strong line with non-TBC frame sync, and thus does pass bad timing and frames, thereby creating drops from capture cards. The DVK is a weak frame, and will balk at "bad" (essentially all VHS) incoming signals. The ES10/15 purifies enough to let the DVK lock, and the final signal is both line and frame timed. But again, with noise/artifacts of the ES10/15. And you definitely do not want an unmodded DVK, those spew noise (and often sound like damaged jet engines).