Quick question -- is there a way to speed up video responsiveness while seeking?

fetidus · 02-24-2018, 04:15 PM

Hi guys -- Quick question -- is there a way to speed up video engine responsiveness while seeking, selecting, and generally navigating around the project/timeline?

In other words, there is a little delay as I seek and select around the timeline as the video engine takes a brief hesitation to seek and display the correct frame. Once it gets going, it's perfectly in sync, but the initial lag seeking to a frame as I navigate around the timeline could be much better IMO. For scrubbing, for example, it's very laggy. Is there a way to improve this speed?

I've tested with different frame sizes, compression, and all files are located on SSD drives, and this is a very fast workstation. Comparatively on the same system, Pro Tools seeks almost instantly to the frame, allowing much smoother scrubbing, seeking, selecting, etc.

It's not a CPU-bound issue since there is tons of overhead available, and it's not a drive issue since this happens on low bandwidth video files on an SSD drive. Just some sort of little delay before Reaper decides to update with the appropriate frame. I'm assuming this is by design, to perhaps preserve CPU resources for the DAW audio engine, etc... but would be nice if I could reduce the delay.

Does this need to be a feature request?

Thanks for any thoughts on this!

JamesPeters · 02-24-2018, 07:26 PM

I'm using Windows 7 64-bit and I can jump around in video files seamlessly ("jumping" the cursor during playback to different spots), also scrub forwards seamlessly (backwards though sometimes it jumps a bit).

Did you check the following option:

"Disable high-resolution peaks for video items"

That helps the performance be faster when you zoom in (although the audio wave view for the item is simplified).

It's under preferences->media->video/rex/misc

Oh also: if you're combining videos of different resolutions/sample rates in a single Reaper project, it might not seek/scrub as smoothly (in the project itself) as if you'd used video items of all the same resolution/sample rate. Periodically when combining various different videos I'd notice the video window would blink at the start or end of a video item, and that was resolved by working with items of the same general specs.

I use VLC as the decoder for the video (for playback) and FFMPEG to encode (although that wouldn't have anything to do with the playback).

fetidus · 02-24-2018, 07:35 PM

Thank you! No luck though. It's still laggy sometimes, especially when I scrub quickly. As long as I move the cursor slowly, there's no issue for the most part, it's very smooth, but when I speed up, it starts lagging or jumping frames. It's worse when I'm zoomed out.

It's not a huge deal... I've seen other DAWs perform similarly, or worse. But it sure would be nice if it didn't lag/gap when I'm moving quickly.

bcslaam · 02-25-2018, 01:10 AM

What codec are you using?

I get laggy response with h264/265 because usually its not encoded as 1 key per frame ie its compressed in blocks of frames and reaper reads each block when seeking. I also have found this to give sub frame inaccuracy.

If I want more accuracy and better seek response I convert to a big mkv huffyuv or mjpeg

fetidus · 02-25-2018, 10:28 AM

I've tried several codecs but will have to double-check which ones. But I know I at least tried a few variants of H.264, including one with keyframes every frame, and I even tried an older DV codec. I want to stick with codecs that Premiere generates BTW, so I don't have to do another step. And unfortunately, Premiere has removed Motion-JPEG, which I used to get decent performance out of in most other DAWs.

In any case the lag really kicks in more when you're zoomed out, or seeking/selecting quickly, and any video file I've tried so far has that kind of performance issue. However, when very zoomed-in on the timeline, the seeking/selecting process is fairly smooth, with occasional lagginess.

It's just not up to the performance that it could be, especially compared to how smooth it is in PT.

JamesPeters · 02-25-2018, 12:52 PM

Weird. I just tried this again, and I'm noticing a delay in how long it takes to seek to a new play position. Whether I'm zoomed in or out, it doesn't matter.

LOL! I just figured out. I had changed seeking behavior to "smooth seeking". This setting doesn't seek immediately; it waits until the end of the measure (or whatever you specify) before seeking to the new position.

Check your options -> preferences -> audio -> seeking. "Do not change playback position immediately when seeking (smooth seek)"

With smooth seek disabled I can seek around a 30 min video file all over the place, zoomed in or out, with maybe 200ms latency. My system is nothing special either: Windows 7, i3 6300, 8GB RAM, Intel HD 530 (onboard video), older SSD.

fetidus · 02-25-2018, 04:33 PM

Hmmm, no luck with this feature either... I already had smooth seek disabled! (Default setting?) Anyway, it's probably a combination of things -- some sort of conservative resource management to prevent video from interrupting the audio engine, and probably a codec performance issue too. I'll continue to experiment and post if I find something new. Any other ideas are more than welcome!

EvilDragon · 02-26-2018, 12:14 AM

Try reducing the media buffer size in Preferences->Audio->Buffering from 1200 ms to a smaller value.

IXix · 02-26-2018, 06:39 AM

I'm certainly no expert but I was looking into video recently and I believe you should convert your video to an "editing" format.

As I understand it, "delivery" formats such as mp4 are very compressed, each frame being somewhat dependent on the surrounding frames, which makes rapid seeking a real pain in the CPU. In an editing format, each frame is a complete entity with no relationship to the surrounding frames, so displaying them quickly is easy.

IIRC, "MKV" is what you want but I could be wrong.

EvilDragon · 02-26-2018, 06:42 AM

MKV and MP4 are just containers... they can contain many different codecs - that's what is actually important.

fetidus · 02-26-2018, 07:04 AM

Quote:

Originally Posted by EvilDragon

Try reducing the media buffer size in Preferences->Audio->Buffering from 1200 ms to a smaller value.

Thanks for the suggestion! Just tried it, but no change in performance of the video lag issues!

IXix · 02-26-2018, 07:04 AM

Quote:

Originally Posted by EvilDragon

MKV and MP4 are just containers... they can contain many different codecs - that's what is actually important.

Quote:

Originally Posted by IXix

I'm certainly no expert

I still think the editing vs. delivery format thing is correct. IIRC I read it in the video sticky and in a linked article but I can't find the links.

edit: found the article - http://telestreamblog.telestream.net...hen-editing-2/

Bri1 · 02-26-2018, 07:10 AM

Ey- ya mkv is a better scrubber! lol-- also--in reaper i found the item fade handles will scrub quiker than cursor will.
I don't think reaper has enough cache (cash?) currently for vids.... =)

fetidus · 02-26-2018, 07:11 AM

Quote:

Originally Posted by IXix

I'm certainly no expert but I was looking into video recently and I believe you should convert your video to an "editing" format.

As I understand it, "delivery" formats such as mp4 are very compressed, each frame being somewhat dependent on the surrounding frames....

Correct, however, sometimes that's not possible in some workflows, and even so, I have indeed been testing various codecs, including 1-frame keyframes on H264 BTW (which solves the inter-frame dependency issues), and other more edit-friendly codecs and they all perform about the same in my case. I have not found a codec or configuration/setting where, on my system, performance is appreciably better than this in Reaper, and this is a very powerful workstation. However, on other DAWs, including Cubase and Pro Tools, for example, the video engines are less laggy. And in some cases, *extremely* smooth for seeking/selecting.

And if we just compare apples-to-apples on the very common consumer, non-edit-friendly H264 codec, Reaper's is among the most laggy engines when zoomed out.

There is clearly some lag/latency as to when Reaper decides to force the video playback window to display the current frame. It's NOT terrible, but it is definitely not as smooth as some other DAWs on the SAME workstation. In my case, I've tried lots of settings and codecs and it just doesn't "fly" like other DAWs with some other codecs. But it is still usable, especially when zoomed in. It just could be much better IMO.

IXix · 02-26-2018, 07:17 AM

Quote:

Originally Posted by fetidus

And if we just compare apples-to-apples on the very common consumer, non-edit-friendly H264 codec, Reaper's is among the most laggy engines when zoomed out.

There is clearly some lag/latency as to when Reaper decides to force the video playback window to display the current frame. It's NOT terrible, but it is definitely not as smooth as some other DAWs on the SAME workstation. In my case, I've tried lots of settings and codecs and it just doesn't "fly" like other DAWs with some other codecs. But it is still usable, especially when zoomed in. It just could be much better IMO.

Fair enough. If you find out how to get better performance, please do let us all know.

fetidus · 02-26-2018, 07:28 AM

Quote:

Originally Posted by IXix

Fair enough. If you find out how to get better performance, please do let us all know.

Definitely will. It's only really irritating when I zoom out, and it's probably just a function of acclimating myself to it. I just finished doing something in DNxHD on Pro Tools, and it's so smooth and seamless by comparison, it's a little jarring to come into Reaper, with ANY codec.

So I started testing the different DAWs with different codecs, and found some interesting surprises. Even Cubase 9.5, with its new, CPU-hogging video engine is LESS laggy with some codecs and file specs. Sometimes its MORE laggy too, lol, it's just not optimized. But Reaper's engine is overall more CPU-friendly, but seems as if there's some inherent design decision that Justin made that creates a little hesitancy before it goes and grabs the right frames. However, zoomed in, it does more or less okay. It feels as if Reaper's design is more zealously protecting CPU resources from spikes from the video engine. Of course I have no way of knowing that, but perhaps Justin made the video engine a little more conservative on the CPU side than the others.

Anyway, very interesting, and I will keep playing around. And I think eventually, if I stay out of Pro Tools and Cubase, it will become "normal" to me. And BTW, other DAWs perform about the same. Studio One's engine, for example, seems about on par with lagginess with Reaper's. And like I mentioned, Cubase's seems both less AND more laggy, depending on the situation. And Pro Tools, depending on the codec, can behave the smoothest of all.

fetidus · 06-02-2018, 09:34 AM

Update for cross-reference, here's another thread about it: https://forum.cockos.com/showthread.php?t=172741