how to edit with reasonable performance

rocket777

Member
I'm trying to edit an mp4 file but the performance is so slow it's impossible.

I recently recorded 5 shows from jeporady on my tivo. I transfered them to my computer, a win10 i7 with 24g ram and a 14 gig ramdisk.

I used vrd to edit out the ads, then converted them to smaller mp4 files using handbrake.

I t hen joined them in vrd into 1 file. But editing these are impossible, even with the file (2 gig .mp4) in a ramdisk. If I try to navigate, it is so slow that a few twirls on the mousewheel can take 20 seconds before it stops moving around. Is there something I can do so this file can be edited in vrd?
 

Danr

Administrator
Staff member
1. Which version are you running (Help>About)?

2. Open the source file, click on Tools>Show Program info and using the copy button in the lower left paste that info into a reply. This will give us more info about the file.

3. You can try running Tools>QuickStream fix and see if that (a) runs quickly, and (b) cleans up the internals of the file to see if makes editing quicker.

4. Have you tried the V6 beta to see if that improves things?
 

rocket777

Member
1. Which version are you running (Help>About)?

2. Open the source file, click on Tools>Show Program info and using the copy button in the lower left paste that info into a reply. This will give us more info about the file.

3. You can try running Tools>QuickStream fix and see if that (a) runs quickly, and (b) cleans up the internals of the file to see if makes editing quicker.

4. Have you tried the V6 beta to see if that improves things?
v 5.4.84.771

(Here's a smaller one, just 3 files, joined)

btw, I cannot load these together using combine, only join

File: Name : A:\files\Jeopardy - 04-09-20 (02) (02).mp4
Size : 0.708 GB
Duration : 00:58:28.41
Mux type : MP4
Video: Encoding : H.264
VideoStreamID : x201
Frame rate : 59.94 fps
Encoding size : 1280 x 720
Aspect ratio : 16:9
Header bit rate : 20.000 Mbps
VBV buffer : 456 KBytes
Profile : Main/4.0
Progressive : Progressive
Chroma : 4:2:0
Entropy mode : CABAC
Bit rate : 1.549 Mbps
Captioning : None found
Audio Stream: 1 (Primary) Codec : AAC
Format : RAW
Channels : 2.0
Language : und
PID : x202
PES Stream Id : xC0
Sampling rate : 48000







quickstream fix doesn't change the performance

no, I haven't tried the v6 beta, I only have a license for v5


Here are 2 individual files I cannot combine (but can join)


File: Name : C:\Users\core5\AppData\Roaming\VideoReDo-TVSuite5\Jeopardy - 04-05-20 (05).VLST
Size : 0.252 GB
Duration : 00:19:24.09
Mux type : MP4
Video: Encoding : H.264
VideoStreamID : x201
Frame rate : 59.94 fps
Encoding size : 1280 x 720
Aspect ratio : 16:9
Header bit rate : 20.000 Mbps
VBV buffer : 456 KBytes
Profile : Main/4.0
Progressive : Progressive
Chroma : 4:2:0
Entropy mode : CABAC
Bit rate : 1.661 Mbps
Captioning : None found
Audio Stream: 1 (Primary) Codec : AAC
Format : RAW
Channels : 2.0
Language : und
PID : x202
PES Stream Id : xC0
Sampling rate : 48000


File: Name : C:\Users\core5\AppData\Roaming\VideoReDo-TVSuite5\Jeopardy - 04-08-20.VLST
Size : 0.243 GB
Duration : 00:19:32.07
Mux type : MP4
Video: Encoding : H.264
VideoStreamID : x201
Frame rate : 59.94 fps
Encoding size : 1280 x 720
Aspect ratio : 16:9
Header bit rate : 20.000 Mbps
VBV buffer : 456 KBytes
Profile : Main/4.0
Progressive : Progressive
Chroma : 4:2:0
Entropy mode : CABAC
Bit rate : 1.594 Mbps
Captioning : None found
Audio Stream: 1 (Primary) Codec : AAC
Format : RAW
Channels : 2.0
Language : und
PID : x202
PES Stream Id : xC0
Sampling rate : 48000
 

Dan203

Senior Developer
Staff member
Go to Tools->Options->Navigation and set the "Force I frame seek" to 0. That should help speed up navigation.
 

rocket777

Member
Go to Tools->Options->Navigation and set the "Force I frame seek" to 0. That should help speed up navigation.
Force IFrame seek after(secs) was already at 0.

I've simplified the test case, I don't have to join any files. While I generally edit files in a ram disk, I get the same performance when the file is on my system ssd. My i7 is a 4790k running at 4 ghz on windows 10 64bit.

Just to be clear about my expectations. If I download from my tivo (I use kmttg) and get a .mpg file, navigation is instant. My mouse-wheel setting is 10 seconds.

If I twirl the mouse, say, 3 times quickly, then in the .mpg file version (before converting with handbrake) the movement is essentially instant, no lag.

If I do the same thing in the .mp4 version (output of handbrake) then it will do each 10 second movement in about 1 second (but jumpy, some a bit slower or quicker), so that there is a lag, and for the next 10-15 seconds I will see navigation of +10 seconds slow enough I can see the time indicator changing roughly once a second. So therefore nothing else can be done until it's complete as these movements are queued up.

I also have control-left/right set to 10 seconds. If I hold down control and tap on, say, right 10 times quickly, in the .mpg version there's no lag, but in the .mp4 version I see the same lag as I do with the scroll wheel.



If you like, upload the files to us and we can check them out. Info on uploading files is here: https://videoredo.net/msgBoard/index.php?resources/uploading-files-to-videoredo-support.1/

Don't forget to send the email to support as that triggers our reviewing your files.
I think I got the upload correct, and I'm sending an email. I uploaded (wheel of fortune, 4/16) where I also have this problem.
I hope this is thread 128579.
 

rocket777

Member
VRD support answered:


I believe the problem is that by default Handbrake creates really long GOPs, about 30+ seconds. Which means that if you need to seek to a frame it on average has to decode at least 15 seconds of content. This is NOT instant.

Change your Handbrake encoding to create an I-frame/GOP every 1 second. This will make navigation comparable to MPEG2.
I put keyint=30 into the handbrake video tab, extra options and re-coded my files. This works. It does make the video somewhat longer, but I can always re-code later without this option and not lose any noticeable quality. Navigation is back to what I have grown to expect.

Thanks.
 

Danr

Administrator
Staff member
I'm curious, how much larger does it make the video? You could probably easily get away with keyint=60, 90 or 120 and still maintain editing speed.
 

rocket777

Member
I'm curious, how much larger does it make the video? You could probably easily get away with keyint=60, 90 or 120 and still maintain editing speed.

Well, I did a few tests, including some comparisons with VLC media player

Code:
Here's my work flow:

I began with yesterday's jeopardy show, using kmttg, downloaded from my tivo,
it's 1.5 gb,

exporting the tivo's add skip data to a .VPrj file, VRD created
a 1 gb file (19:37 length).

Sending this file to handbrake, with the following parameters (using
copy from the extra options),
-----------------------
keyint=30:level=4.0:ref=1:8x8dct=0:weightp=1:subme=2:mixed-refs=0:trellis=0:vbv-bufsize=25000:vbv-maxrate=20000:rc-lookahead=10

file size 378 mb
-----------------------
keyint=90:level=4.0:ref=1:8x8dct=0:weightp=1:subme=2:mixed-refs=0:trellis=0:vbv-bufsize=25000:vbv-maxrate=20000:rc-lookahead=10

file size 282 mb

This has a bit of a lag, though fairly usable, holding down the right/left arrow key to skip around
not as nice as with keyint=30
-----------------------
level=4.0:ref=1:8x8dct=0:weightp=1:subme=2:mixed-refs=0:trellis=0:vbv-bufsize=25000:vbv-maxrate=20000:rc-lookahead=10
(no keyint entry used)

file size 242 mb
-----------------------
I also did a comparison of performance with VLC media player:

I have a program that can send commands to VLC to skip +/- 3 seconds on mousewheel events.
While I see roughly the same amount of cpu time (about 25% on a 4 core 8 thread 4790k)
between VRD and VLC while doing mouse twirls, VLC shows no lag. For the compare, I
set the mousewheel to 1 second in VRD, so it should be comparable.

In both VRD and VLC I can see roughly the same number and size of i/o, about 100
for read delta and 2000KB or so read bytes delta (1 second update rate in procexp)

This comparison was with the slow version (no keyint).

So, I'm a little bit surprised that VRD has these lags as they each seem to be doing
about the same amount of work.

Note that in all cases I'm running out of a ramdisk.

I understand that v6 can do more buffering and possibly eliminates the problem. I've
not tested that.

But for now, I have a workaround using the keyint parameter in handbrake, and I'm just
doing a little bit of editing.

Hope this helps.
 
Last edited:
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