Loudnorm causes rendering to fail on Voukoder Pro

Simply adding the audio filter causes immediate failure of Voukoder Pro to render. Vegas stops instantly with a "unable to start Voukoder Pro" error on render. Removing the filter restores normal operation. This is on all default settings.

First capture is without LOUDNORM, works perfectly. Although weirdly, when batch rendering regions in Vegas, it's losing about 20% speed each regions as it progresses through them .... e.g. 80fps, then 64fps, then 50fps, then 35fps, then 20fps, etc until it slows to a crawl. There's no visible memory leak detectable in Task Manager for either CPU or GPU.

voukoder1.txt

Second capture is with LOUDNORM, same profile, just inserted in between audio IN and render OUT. This immediately fails, and the rejected bitrate message is curious because the same bitrate works perfectly in the above profile without LOUDNESS. It also works as expected when used in ffmpeg from command line : -af loudnorm=I=-24:LRA=11:TP=-2

voukoder2.txt

And for whatever it's worth, these are the scene files from Vegas 22, I couldn't find Voukoder's storage location for its profiles.

voukoder pro.zip

Thank You!

This is still broken in Voukoder 2026 :

2026-01-02 11:42:02 (info) System information:

CPU(s):
Socket 0:
Vendor: GenuineIntel
Model: Intel(R) Core(TM) i7-14700K
Cores: 20/28

Memory:
Total: 65536 MB
Free: 27567 MB
Available: 27568 MB

GPU(s):
Card 0:
Vendor: Amyuni
Model: USB Mobile Monitor Virtual Display
Driver version: 2.0.0.1
Card 1:
Vendor: LuminonCore
Model: LuminonCore IDDCX Adapter
Driver version: 1.0.2018.1204
Card 2:
Vendor: NVIDIA
Model: NVIDIA GeForce RTX 4060 Ti
Driver version: 32.0.15.8097

Operating System:
Name: Microsoft Windows 10 Pro
Version: 19045
Architecture: 64 bit
.
2026-01-02 11:42:02 (info) Validating license ...
2026-01-02 11:42:02 (info) License is valid!
2026-01-02 11:42:02 (info) Counting seat usage ...
2026-01-02 11:42:03 (info) Active seats: 1 / 1 seats
2026-01-02 11:42:03 (debug) License responder started ...
2026-01-02 11:42:03 (info) ### PHASE: PRE-INIT
2026-01-02 11:42:03 (debug) Filter config: abuffer@491abb00bc9641cca9ebb07bf107b1b6=sample_rate=48000:sample_fmt=flt:channel_layout=stereo,loudnorm,aformat=sample_fmts=fltp,abuffersink@79de9b8b101d486e9ae1f061592c6d22
2026-01-02 11:42:03 (info) ### PHASE: INIT
2026-01-02 11:42:03 (debug) Dumping filter graphfor NLE Track #1:
+------------------------------------------+
| abuffer@491abb00bc9641cca9ebb07bf107b1b6 |default--[48000Hz flt:stereo]--auto_aresample_0:default
| (abuffer) |
+------------------------------------------+

+-------------------+
auto_aresample_0:default--[192000Hz dbl:stereo]--default| Parsed_loudnorm_1 |default--[192000Hz dbl:stereo]--auto_aresample_1:default
| (loudnorm) |
+-------------------+

+------------------+
auto_aresample_1:default--[192000Hz fltp:stereo]--default| Parsed_aformat_2 |default--[192000Hz fltp:stereo]--abuffersink@79de9b8b101d486e9ae1f061592c6d22:default
| (aformat) |
+------------------+

+----------------------------------------------+
Parsed_aformat_2:default--[192000Hz fltp:stereo]--default| abuffersink@79de9b8b101d486e9ae1f061592c6d22 |
| (abuffersink) |
+----------------------------------------------+

+------------------+
abuffer@491abb00bc9641cca9ebb07bf107b1b6:default--[48000Hz flt:stereo]--default| auto_aresample_0 |default--[192000Hz dbl:stereo]--Parsed_loudnorm_1:default
| (aresample) |
+------------------+

+------------------+
Parsed_loudnorm_1:default--[192000Hz dbl:stereo]--default| auto_aresample_1 |default--[192000Hz fltp:stereo]--Parsed_aformat_2:default
| (aresample) |
+------------------+
2026-01-02 11:42:03 (info) Initializing audio encoder: aac
2026-01-02 11:42:03 (info) Successfully initialized the output format.
2026-01-02 11:42:03 (info) ### PHASE: PRE-INIT
2026-01-02 11:42:03 (debug) Filter config: buffer@a539ecc215e24336a5406809b8429260=width=1920:height=1080:pix_fmt=yuv420p:time_base=1/30:pixel_aspect=1/1,format=pix_fmts=yuv420p,buffersink@e11b009cad9b4b4bb0c45eff2a427f79
2026-01-02 11:42:03 (info) ### PHASE: INIT
2026-01-02 11:42:03 (debug) Dumping filter graphfor NLE Track #0:
+-----------------------------------------+
| buffer@a539ecc215e24336a5406809b8429260 |default--[1920x1080 1:1 yuv420p]--Parsed_format_1:default
| (buffer) |
+-----------------------------------------+

+-----------------+
buffer@a539ecc215e24336a5406809b8429260:default--[1920x1080 1:1 yuv420p]--default| Parsed_format_1 |default--[1920x1080 1:1 yuv420p]--buffersink@e11b009cad9b4b4bb0c45eff2a427f79:default
| (format) |
+-----------------+

+---------------------------------------------+
Parsed_format_1:default--[1920x1080 1:1 yuv420p]--default| buffersink@e11b009cad9b4b4bb0c45eff2a427f79 |
| (buffersink) |
+---------------------------------------------+
2026-01-02 11:42:03 (info) Initializing video encoder: h264_nvenc
2026-01-02 11:42:03 (info) Initialization succeeded.
2026-01-02 11:42:03 (info) ### PHASE: PRE-OPEN
2026-01-02 11:42:03 (info) Registering 1 audio stream(s)
2026-01-02 11:42:03 (debug) Registered stream 79de9b8b-101d-486e-9ae1-f061592c6d22:0
2026-01-02 11:42:03 (info) Registering 1 video stream(s)
2026-01-02 11:42:03 (debug) Registered stream e11b009c-ad9b-4b4b-b0c4-5eff2a427f79:1
2026-01-02 11:42:03 (info) Pre-open phase succeeded.
2026-01-02 11:42:03 (info) ### PHASE: OPEN
2026-01-02 11:42:03 (info) Opening audio encoder plugin 'aac' with params '{"rc":"cbr","b":96000,"profile":"aac_low","cutoff":20000}'
2026-01-02 11:42:03 (error) Opening the encoder plugin failed with error code: -22
2026-01-02 11:42:03 (error) Open phase failed: -11
----
Exported 0 frames in 0 seconds.
This is a theoretical average export speed of 0 fps.
IMPORTANT! Real exports using an NLE might be slower due to the NLE overhead.