DirectShow Capture Source and FFMPEG

I have an AJA Capture card. The drivers installed with the card include some DirectShow filter. If I pop the filter into GraphEdit I see this:

AJA Capture Filter in GraphEdit

and if I run the ffmpeg command

ffmpeg -f dshow -list_options true -i video="AJA Capture Source"

I see

[dshow @ 0034eec0] DirectShow video device options
[dshow @ 0034eec0]  Pin "Video"
[dshow @ 0034eec0]   pixel_format=yuyv422  min s=720x486 fps=27.2604 max s=1024x
486 fps=29.985
...
[dshow @ 0034eec0]  Pin "Audio 1-2"
[dshow @ 0034eec0]  Pin "Line21"
video=AJA Capture Source: Immediate exit requested

So I see the Video and Audio pins I need. But when I try to run an ffmpeg command to capture both, I can only figure out how to do the video part. How do I hook in to that audio pin? It seems all the examples and documentation point to using a separate audio device, and nothing about hooking into the pins. I'm running it out of a batch file for now like this and I use the ^ to break the line

ffmpeg.exe ^
-y ^
-rtbufsize 100M ^
-f dshow ^
-i video="AJA Capture Source" ^
-t 00:00:10 ^
-aspect 16:9 ^
-c:v libx264 ^
"C:\VCS_AUD_SAMPLE.mp4"

Again, the command above will get me some beautiful video, but I can't figure out the audio part. Is this even supported in ffmpeg or am I going to have to modify the ffmpeg dshow code?

Solution

So after tracing through source code of FFmpeg it was deemed that it could not hook up to multiple pins on a dshow source, so instead of modifying the FFmpeg source, we piped the AJA source pins through two virtual capture sources to achieve the desired result.