I would like to report on rendering surround sound from Vegas Pro. I think the concept can be applied to other setups using Voukoder. Just to recap, most video software packages no longer allow the export or rendering of 5.1 surround sound. This is due to issues with using Dolby. Up until recently Power Director could do Dolby output. Power Director still does 5.1 but not with Dolby.
What I am using
Vegas Pro 19
Voukoder: 7.0.115
Voukoder Connector for Vegas Pro 19: 1.6.0
Audacity
ZOOM H2n surround sound microphone
I am using Voukoder 7 because it works and has the ability to engage the use of the GPU for processing e.g., HEVC (NVIDIA NVENC. I think more versions will do this except the most recent as updates for the GPU is necessary and those are not available yet.)
ZOOM H2n gives four channels two stereo front facing and two stereo rear facing. Thus, you get a wav file with four channels. To line up the Zoom wave file I create a distinct noise that is recorded in the ZOOM and in the video recording. This way the spike noise can be lined up.
Audacity is used to process the four channels into 5.1 surround sound. Audacity will create the following channel order L, R, C, LFE, Ls, Rs. However, this is not the order that is out put from Voukoder. That output has the order L, C, R, Ls, Rs, LFE. So to make the rendering easy, I assign the audio tracks in the order.
The four tracks are brought into Audacity, the front two first and the rear to below. In the export to the was file, Left Front is linked to Channel 1, Left Front and Right Front are linked to Channel 2, Right Front is linked to Channel 3, Left Rear is linked to Channel 4, Right Rear is linked to Channel 5, and Left Rear and Right Rear are linked to Channel 6. One can experiment with assigning tracks to the Center (Channel 2) and the LFE (Channel 6). I just find this easy.
The video is brought into Vegas 19 and color graded. I use either HLG or no Picture Profile (I may or may not use a LUT here). For the HLG I set the Project Properties to 4K 32-bit floating point (full range) and the view transform to Rec. 2020 HLG 1000 nits. Both approaches are set to 5.1 audio. I then do further color grading as necessary.
I then bring in the 5.1 wav file into the video and line this up with the audio track on the video. Once that is done, I unlink the audio from the video and remove this audio track. The panner is then used to assign each track to the proper channel (L, C, R, Ls, Rs, LFE). This overrides the order from Audacity.
For rendering in Voukoder, for me the 4.2.0 8-bit or 10-bit Audio project defaults are used. The Video Encoder is set to HEVC (NVIDIA NVENC) and the Audio is set to AC3. Then it is rendered.
The HLG can give a nice-looking video. Obvious it can be used to create HDR-HLG videos. Unfortunately, Voukoder can not do HDR as of yet.
Hope this is helpful for some.