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funny_Cosmos5FD4
Participant
January 10, 2020
Question

very slow preview and no audio at ProRes LT

  • January 10, 2020
  • 1 reply
  • 684 views

Hi,

 

we are experimenting with a greenscreen composition where the footage is a ProRes LT 1080/50P Video.

 

We have basically two issues:

 

- There is no proper preview, even though preview resolution is already set to 1/3.

 

Hardware: (6-core CPU I74960X, with 16GB RAM, 250GB System SSD, 2TB Project SSD, Radeon R9 280X), 

 

In case we play at a timeline position which is already rendered (green line can be seen) the playback is very slow (around 50%). All the CPU cores are used at 30-40%. RAM is 95% used. RAM itself should be no problem. If the RAM is not enough the length of the green line (prerendered area) would be simply shorter. Realtime Playback should be no problem. CPU seems to be also OK. All the 12 vCores are below 50%. 

 

- We have no audio if played on the timeline (audio preview is activated)

 

If we use an mp3 file on the timeline, it can be heard. Project and composition seem to be OK.

If we use the ProRes recording of our Atomos Shogun, a waveform will be shown in the list, no waveform will however indicated of we use it on the timeline.

 

Is AE CC generally compatible with ProRes? Image is no Problem, it seems however a bit smoother on the timeline (also at full resolution) than in GV Edius. Is it possible to use Lanczos3 for image scaling? I have found bilinear and bicubic only ...

 

Thank you very much for your reply.

 

Best regards

 

I.

 

This topic has been closed for replies.

1 reply

Warren Heaton
Community Expert
Warren HeatonCommunity Expert
Community Expert
January 11, 2020

If you select the clip in the Project tab and look at the Poster Preview at the top, do you see audio information as well as picture information?

 

If you open the clip in Premiere Pro and view it in the Source tab, do you see an audio waveform?

 

As far as smooth playback is concerned in the Comp, there's just the time it takes to decompress the the source footage and the time it takes to read the file from your storage media which should be very fast for ProRes.  Once it's loaded into RAM, it's the same as any other source footage to After Effects.

 

Did you opt for RT for file size?  Green screen is usually shot at Apple ProRes4444.

 

 

 

 

F
funny_Cosmos5FD4Author
Participant
January 11, 2020

Thank you, Warren, for your feedback. 

 

#1 yes, if you add the video file to the project, audio will be recognized, there is however no waveform on the timeline. An MP3 generates waveform also on the timeline. 

 

 

#2 we use for system and projects two different Samsung SSD. I think they are fast enough. Yes, we have chosen ProRes LT because of file size. 140Mbits are generally good enough. We will however test with some uncompressed codecs. I estimate however that the current workstation won't be able to edit it in real time. 

 

For your interest, here is a shot recording with our camera (Panasonic AG AJ PX 271): 

https://nx8213.your-storageshare.de/s/EGYzGNj43rrtfr6

(This is a P2 News camera with an 1/3" Sensor.) 

The recording on the Atomos Shogun is not spotless. I see a grainy-noisy indoor footage, even though the scene was lit strong enough. Aperture was not fully opened. Also the edge of the person is pretty wide, causing troubles in AE.

Is this noisy-ness because of the small sensor or because of the low quality codec? Would you suggest a full sensor cam like Panasonic GH5 or anything like this? Or we need simply a 4K cam with a better resolution?

 

Thank you for your reply in advance. 

 

Best regards

 

I.

 

 

Warren Heaton
Community Expert
Warren HeatonCommunity Expert
Community Expert
January 14, 2020

Your source video has multi-channel audio and it's recorded in tracks 3, 4, 5 and 6.

 

 

Switch to recording to channel 1 and 2 in the future and you should be good to work with the files directly in AE and hear the audio.

 

For your current MOV files, you can export the audio as a stereo mixdown pretty quickly by importing the MOV into Premiere Pro, creating a new Sequence from the clip (Premiere should default to a Stereo Mixdown for the Sequence Audio Settings) and then do an Audio Only export.  Add the resulting audio file to your corresponding Comp in After Effects and you should be good.

 

I also tried Audition, but I was getting unexpected results when exporting a stereo mixdown.

 

I also tried using Replace with After Effects Composition in Premiere Pro.  While it looked like the audio channels went to an After Effects Comp as expected, the AE Layers with audio were all silent on the AE side.

 

I extracted the the audio from the file that you made available and posted a download link below.

 

 

-Warren

 

 

 

Filename: SHGINF_S001_S001_T039.AIF

https://drive.google.com/open?id=1TQ2bkLjUPH7rdYJggUtqCoTLT7akHMew

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