Audio drop-outs in rendered video-file.

GARPENHOLM wrote on 7/16/2018, 2:02 PM

I have a 4:15 min mp4 (4K AVC (3840x2160x32) 30 fps) and six extra audio tracks in FLAC format (24-bit 96 kHz stereo).

After redering I get random audio drop-outs in different audio part/tracks encoded into the final mp4 file.I have tried to render with AMD, nVidia and just CPU, but it's the same issue regardless of how I render.

Software:
I use Vegas Pro 365 Version 15.0 (build 361)
Windows 10 Pro 64-bit

Hardware:
I use a Lenovo D30 workstation with two six-core Intel Xeon E5 2630 v2 @ 2.60GHz
24,0GB Triple-Channel DDR3 @ 799MHz (11-11-11-28)
3071MB NVIDIA Quadro K4000 (NVIDIA)
4096MB ATI AMD FirePro W7000 (AMD)
ForceWare version: 397.93
465GB Samsung SSD 860 EVO 500GB (SATA (SSD))
 

 

 

Comments

rraud wrote on 7/16/2018, 4:00 PM

What is the result when you render a PCM (.wav) or an audio-only MP4?

If it's the same, try pre-rendering the FLAC files to PCM.

GARPENHOLM wrote on 7/16/2018, 4:41 PM

It still drops-out randomly. I've tried to render to MP3 320 kbps and to WAV 16-bit 44.1KHz just right now with the same random dropouts. When I preview (live) in Vegas I'm also able to see how different channels drops out randomly. (The VU-meters drops to zero). It seems to be worse near the end of the clip. But it's random. No issues or errors in the raw materals.

GARPENHOLM wrote on 7/16/2018, 5:01 PM

Is there an easy way to 'replace' an audio file in a Vegas Pro 15 track without losing any events?

rraud wrote on 7/17/2018, 11:19 AM

Is there an easy way to 'replace' an audio file in a Vegas Pro 15 track without losing any events?


A few ways

For an audio only event (for instance music BG) "View> Project media> Right click the desired media' and select 'Replace'.

You can also create a new 'Take' which will put a new event on top of the old (you can also toggle between the two if desired ).

For embedded audio, you could just add new audio tracks and mute the undesired, or select 'Ignore event grouping' (or un-group) and 'delete' the undesired audio event(s) from the project.

GARPENHOLM wrote on 7/18/2018, 2:09 PM

I can't find any "Project media" in the "View-menu", neither can I find any "Replace" when right-clicking on any of my tracks.

vkmast wrote on 7/18/2018, 2:53 PM

In Project Media tab, right-click on your clip and choose Replace.

See that View > Window > Project Media is checked.

GARPENHOLM wrote on 7/18/2018, 4:22 PM

OK, a nice to have feature would be to be able to right-click directly on the clip in the edit-window and "replace" a source-clip that way.

Anyway...

The clipping-/drop-out-issue disappeared when I use 16-bit 44.1kHz wav (PCM) instead of FLAC, so the main problem is solved in my project (but with a slightly worse audio quality).

BUT, why can't it play/render FLAC lossless? - When I 'render' a project it shouldn't be depending on real-time performance should it?!

rraud wrote on 7/19/2018, 10:23 AM

PCM has superior quality to FLAC or anything else for that matter. If you render a PCM from a FLAC, there would be negligible quality loss.

The FLAC codec probably is corrupted. Performance wise, the rendered file is usually not affected.

GARPENHOLM wrote on 7/19/2018, 3:23 PM

I encoded my FLAC directly from my DAW (Presonus Studio One 4), it's 96 kHz, 24-bit.

When I transcoded the FLAC into PCM I used SOUND FORGE Audio Studio 12.6 and could only transcode it in 16-bit. But it's good enugh for this video.

Thank you for your help and information!