Best bitrate for editing SD in Sony Vegas

[lonrot]

Hi,

Performance-wise, What are the correct bitrate settings for timeline editing mpeg2 proxies at 640x360p with Vega's Main Concept MPEG-2 plugin/encoder?

By the way, HC GUI renders videos with different duration, so I prefer Vega's built-in rendering.

[poisondeathray]

What do you mean "performance wise" ?

Did you mean scrubbing/timeline responsiveness?

It doesn't make much of a difference with bitrate, especially at SD resolution proxies if you have a decent computer. Lower bitrates might be very slightly better / more responsive. A more noticable difference would be using an I-frame intermediate vs. long GOP.

[lonrot]

What do you mean "performance wise" ?

Did you mean scrubbing/timeline responsiveness?

Yes, exactly timeline responsiveness. My editing usually consists of two video tracks at 720p: webcam and game footage and after 30 minutes of cuts it becomes extremely unresponsive, even with proxies, so now I want to go even lower with 360p proxies.

Can you tell if the settings below are correct?

[smrpix]

DV actually makes an excellent proxy -- i-frame editing, relatively clean image, etc. Low bitrate i-frame h.264 also works, but tends to be too blurry to judge focus.

edit: (Cross-posted.) i-frame (no GOPS) is more important than raster size or bitrate for responsive editing.

[poisondeathray]

I'm guessing from your other thread, that you're using vegas' internal smart proxy feature. I haven't used it

But in general, MPEG2 editing responsiveness will be noticibly better if you use I-frame only (ie. set I frames to 1, b-frames to zero)

Bitrate doesn't really affect responsiveness much, unless it's really high

smrpix raises a good point about quality - for proxy edits all you need is "good enough" for what you are doing. If you need to resolve fine details, maybe fine mask work - then obviously you can't use a low res/ low quality proxy for that .

[poisondeathray]

Yes, exactly timeline responsiveness. My editing usually consists of two video tracks at 720p: webcam and game footage and after 30 minutes of cuts it becomes extremely unresponsive, even with proxies, so now I want to go even lower with 360p proxies.

That "after 30 minutes" and "extremely unresponsive" makes me think it's not a proxy related or decoding issue . There is something else going on causing you to freeze. If decoding was an issue, it would be sluggish editing right at the beginning

Are you running 64bit ? What is the memory situation like? Open up taskmanager

[smrpix]

Longer long-GOP files tend to get sluggish with heavy cutting in all NLEs. Try breaking your files into shorter chunks or edit in sub-sequences of 10 minutes or less.

[poisondeathray]

"extremely unresponsive" suggests something several orders more severe than "sluggish" to me. Maybe he can clarify

2 SD streams , even MPEG2 long gop, should be a piece of cake even with hours of footage and hundreds of cuts . Something else is going on, memory, or computer is slow, or storage issues

[lonrot]

Yes, exactly timeline responsiveness. My editing usually consists of two video tracks at 720p: webcam and game footage and after 30 minutes of cuts it becomes extremely unresponsive, even with proxies, so now I want to go even lower with 360p proxies.

That "after 30 minutes" and "extremely unresponsive" makes me think it's not a proxy related or decoding issue . There is something else going on causing you to freeze. If decoding was an issue, it would be sluggish editing right at the beginning

Are you running 64bit ? What is the memory situation like? Open up taskmanager

Windows 8.1 Pro 64bit, it seems to be a memory bottleneck, once I make a lot of cuts (every 30 seconds or less), switching back and forth causes the preview window to respond very slowly, I often lay back for some minutes, drink some coffee and when I come back the preview windows is much faster. Oddly enough no other programs or background processes are slowed down, only Vega's preview window.

It would be nice to have a "Flush Memory" button like in After Effects.

Btw Dynamic RAM preview is disabled due to constant crashes.

Here's how the task manager looks like (prior memory bottleneck):

[poisondeathray]

Did you check taskmanager when you were in the middle of the project with the "extremely unresponsive" periods ?

If it is a memory issue, then adding system memory would help

Oddly enough no other programs or background processes are slowed down, only Vega's preview window.

But if other programs aren't slowed down at that time and you aren't maxed out with memory consumption, that suggests system memory isn't the problem

[lonrot]

Going back to settings:

Should I leave the "Advanced video" settings as it is?

I have only changed I-frames to 1 and B-franes to 0.

Use closed GOPS is unchecked.

Did you check taskmanager when you were in the middle of the project with the "extremely unresponsive" periods ?

Will do next time :P

[poisondeathray]

closed GOP is irrelevant with a GOP size of 1 (they are all closed) .

But closed GOP's can help with long GOP proxies

The other mpeg2 config settings won't matter for your purpose

I wonder if it has something to do with vegas's internal proxy implementation ? Maybe the dynamic switching ? Do you have preview set to a set quality level like "draft" (not "automatic")? Maybe old skool proxy method would be more stable ?

[lonrot]

closed GOP is irrelevant with a GOP size of 1 (they are all closed) .

But closed GOP's can help with long GOP proxies

I wonder if it has something to do with vegas's internal proxy implementation ? Maybe the dynamic switching ? Do you have preview set to a set quality level like "draft" (not "automatic")? Maybe old skool proxy method would be more stable ?

Yes, I'm doing it manually (replacing clips). Now that I remember I have only worked with one webcam proxy since the game footage contains two tracks. I just realized I can group the proxy with the two tracks. Now I will do proxies for both videos and see how it goes.

Sorry for the misinformation.

The gaming footage is 1280x720p MPEG-1 VBR so that's probably why the preview window gets stuck. And yes I often work with the draft preview window.

[lonrot]

GOP settings are somewhat confusing.

If I check closed GOPs a submenu asks for: None short, First short, All short.

None short is set by default.

[Cornucopia]

Agree with what the others have been telling you:
1. I-frame best, Short Closed GOP good, Long Open GOP worse
2. Rez and/or quality should be lower when doing proxy work - the point is to ease the CPU's burden
3. In keeping with that, less complex codecs are more responsive than more complex. So DV->MPG1->MPG2->MPG4->AVC is the main progression.

Also, it looks to me like you need to give your machine a break and stop running other processes when editing:
From that picture, Dropbox, WinSearchIndexer, DesktopWinMgr, Greenshot, AdobeReader, poss. 2nd instance of Explorer shouldn't be running concurrently. There may be others that aren't showing up, too. Think Lean, mean fighting machine!

Scott

[poisondeathray]

GOP settings are somewhat confusing.

If I check closed GOPs a submenu asks for: None short, First short, All short.

None short is set by default.

Again, it's irrelevant with I-frame only. (GOP size of 1). That setting only applies with long GOP, so you can leave it (it does nothing with I-frame only)

[lonrot]

Agree with what the others have been telling you:
1. I-frame best, Short Closed GOP good, Long Open GOP worse
2. Rez and/or quality should be lower when doing proxy work - the point is to ease the CPU's burden
3. In keeping with that, less complex codecs are more responsive than more complex. So DV->MPG1->MPG2->MPG4->AVC is the main progression.

Also, it looks to me like you need to give your machine a break and stop running other processes when editing:
From that picture, Dropbox, WinSearchIndexer, DesktopWinMgr, Greenshot, AdobeReader, poss. 2nd instance of Explorer shouldn't be running concurrently. There may be others that aren't showing up, too. Think Lean, mean fighting machine!

Scott

Thanks for the input Cornuccopia. So none short is short?

[lonrot]

Again, it's irrelevant with I-frame only. (GOP size of 1). That setting only applies with long GOP, so you can leave it (it does nothing with I-frame only)

Understood. Thanks a lot poison!

[Cornucopia]

Didn't you just read what pdr just said? It doesn't matter for I-frame-only GOPs.

IF you were NOT using I-frame-only GOPs, it would matter. And in that instance, what I believe that dropdown to mean is:
1. All short = Every GOP in the media & sequence renders is a short GOP from start to finish.
2. First short = Every GOP in each piece of media (and in each render of whatever sequence) STARTS with a short GOP and then defaults to "auto" or long after that.
3. None short = Every GOP in the media & renders defaults to "auto" or long THROUGHOUT the entirety of each piece.

But you're going to put that aside and listen to us, right?

Scott

(I get it, there's a delay in writing the responses...)

[lonrot]

But you're going to put that aside and listen to us, right?

Yeah now I get it, the concept of GOP is very novel to me. I barely grasped the concept hours ago.

[lonrot]

The proxy file seems to be unrecognizable by Vegas but can be opened by any video player and plays fine.

Vegas says:

*.m2t could not be opened. Make sure the file exists or you have access to the file/folder

General
ID                                       : 0 (0x0)
Complete name                            : C:\VIDEO\hotlineFootage68.m2t
Format                                   : MPEG-TS
File size                                : 6.63 GiB
Duration                                 : 1h 30mn
Overall bit rate mode                    : Constant
Overall bit rate                         : 10.6 Mbps

Video
ID                                       : 1001 (0x3E9)
Menu ID                                  : 1 (0x1)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings, BVOP                    : No
Format settings, Matrix                  : Default
Format settings, GOP                     : N=1
Codec ID                                 : 2
Duration                                 : 1h 29mn
Bit rate                                 : 9 643 Kbps
Maximum bit rate                         : 9 800 Kbps
Width                                    : 640 pixels
Height                                   : 360 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 29.970 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 1.396
Time code of first frame                 : 00:00:00:00
Time code source                         : Group of pictures header
Stream size                              : 6.06 GiB (91%)

Audio
ID                                       : 1002 (0x3EA)
Menu ID                                  : 1 (0x1)
Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 2
Codec ID                                 : 3
Duration                                 : 1h 29mn
Bit rate mode                            : Constant
Bit rate                                 : 384 Kbps
Channel(s)                               : 2 channels
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Stream size                              : 247 MiB (4%)

[lonrot]

Anyone?

[smrpix]

Try Mpeg2 version 2 for the audio. Other than that, no idea. A similar file loads fine in Vegas Movie Studio. Post a sample if you want others to take a look.

(Also, your bitrate is higher than necessary for that size image, and PCM audio is a good, lossless choice, allowing you to only replace video when you relink.)

[Cornucopia]

@smrpix, MpegLayer 2 for 384kbps, 48kHz, 2ch is going to be v1. v2 applies to (and kicks in on) low bitrate or low samplerate options only. Plus, v2 is backwards compatible to v1, so any app/device that supports v2 must support v1 as well.

Honestly, I don't know why you are compressing your audio instead of leaving it as LPCM. Just to keep it inside the TS? Well that's weird since AVCHD uses LPCM (or AC3, your choice) in MTS files. Stick with one of those.

Scott

[smrpix]

@Scott -- it was a shot in the dark. While that file may be less than optimal, I really can't see any reason it shouldn't work.

[poisondeathray]

isn't it a bit weird that vegas can't import it's own export ??

You can try re-wrapping it into a mpeg2-program stream (.mpg) e.g. with ffmpeg

[Cornucopia]

@smrpix, me neither.

@pdr, that happens all the time (you probably know that, though) - install includes encoder but not decoder, or vice-versa, usually for financial or legal reasons.

I thought the re-wrap might work also. Maybe the OP is trying to keep it MTS because they're doing a file-name-identical proxy replace?

Scott

[lonrot]

The audio wasn't the issue, even rendered with sound disabled.

Vegas doesn't like B-frame set to 0. I changed I-frame to 2 and b-frame to 1 and the clip was imported instantly.

Why?

[poisondeathray]

That's weird, because I-frame only MPEG2 intermediates are frequently used in vegas.

In fact, one of the most common workflows in the past , for proxy editing was ffmpeg batch encoding to MPEG2 I-frame intermediate

[Cornucopia]

Just did a bit of testing and I've found a really cool way to use PNG sequence (usually in MOV container) for proxies, using a reduced palette!

Example: 720p60 221frames (logo sweep)
Uncompressed24bit = 600MB
DNxHD8bit147=65MB
DV100=52MB
Cineform24bit=49MB
ProRes422std=41MB
PNG24bit=32MB
ProResProxyFull=20MB
PNG24bit-reducedPalette(03bitPosterization)=6MB

ProRes & Cineform overall had the best (least) CPU utilization in multicore (proxy was better than std, obviously by nature but also tested), DNxHD was a little worse, DV100 was much worse. PNG & PNGrp were weird: med-high on 1st core, but low on other core(s). Probably not coded well. Still, if you DON'T need to worry about color purity during your rough edit stage, it is SMALL! and runs pretty darn smooth.
Didn't try mpeg Intra or AVC Intra this time (wouldn't make sense for proxies trying to reduce CPU load).
Didn't try multiple layers or edits, though - some other time.

Note: rp doesn't work well within most "24bit-optimized" DCT-type compression products, in fact it often makes them larger than normal palette versions. Tried it.

Food for thought...

Scott

<edit>Probably not going to change my workflow using ProRes, Cineform, etc (because they clearly have been well-tuned), but it's nice to have an extra tool in your back pocket!</edit>