Mapping audio channels when using Full Decoding

[FranceBB]

Hi,
My workflows are based on an 8ch audio XDCAM50 output with a Full Decode and additional Avisynth filters (custom Avisynth Scripts) and they work pretty well.
The problem is that my output files need to be with 8 full audio channels.
Mapping audio channels using if conditionals with the following logic is pretty easy:

if %i_a_channels% <= 0 then -> next block
if %i_a_channels% = 1 then channel mapper 1->1, 1->2, 1->3, 1->4, 1->5, 1->6, 1->7, 1->8
if %i_a_channels% = 2 then channel mapper 1->1, 2->2, 1->3, 2->4, 1->5, 2->6, 1->7, 2->8
if %i_a_channels% = 3 then channel mapper 1->1, 2->2, 3->3, 1->4, 2->5, 3->6, 1->7, 2->8
if %i_a_channels% = 4 then channel mapper 1->1, 2->2, 3->3, 4->4, 1->5, 2->6, 3->7, 4->8
if %i_a_channels% = 5 then channel mapper 1->1, 2->2, 3->3, 4->4, 5->5, 1->6, 2->7, 3->8
if %i_a_channels% = 6 then channel mapper 1->1, 2->2, 3->3, 4->4, 5->5, 6->6, 1->7, 2->8
if %i_a_channels% = 7 then channel mapper 1->1, 2->2, 3->3, 4->4, 5->5, 6->6, 7->7, 1->8
if %i_a_channels% >= 8 then -> next block

The problem is that Full AV Media Decoder always creates 32 audio tracks, so I can't really know how many tracks my original file has, therefore I can't map audio channels.

Any thoughts?

Thank you in advance.

[admin]

Hi FranceBB,

You need to store the %i_a_channels% value in a user variable before it's changed by the "A/V Media" decoder. That is; add a "Populate variables"-node before decoding and set <your_variable> = %i_a_channels%. Then use <your_variable> to check for total number of channels.

Hope this helps.

-steinar

[FranceBB]

Right, got it. I've done it, it works.