b5: Sony camera proxy workflow issue (FS5)

First of all: the new Proxy Media workflow is great functionality!

I use Sony cameras, the PXW-FS5 and PXW-X70. Mostly I generate camera proxy files when recording, and it would be great to use them directly in Resolve. The camera proxy files have S03 appended to the clip names, but a file renaming ulility should take care of that, renaming to the same name as the clips. Formats are .MXF for clips, .MP4 for proxies. Resolve can read both file types. Details from MediaInfo at the bottom of this post.

Using Resolve Studio 17.0 beta 5 in Windows 10 Pro v.1909, on MS Surface Pro 6, i7-8650U, 16 GB,
1 TB, GPU: Intel UHD Graphics 620, 8GB GPU memory. (I use that PC to test version 17 betas, my "production"-PC has more resources. Would love to be able to use the Surface for proxy workflow editing.)

Unfortunately I can't get it to work as I would like. The odd behaviour I experience is:

After dragging the clips to the project in the Media page, I select them and select Link Proxy Media... in the right click menu, and that goes well, it seems. Proxy resolution is 1280x720, and Proxy Media Path is correct. The strange behaviour is with the audio, though.

The MXF clips have 4 channels of mono audio, of which 1 and 2 are used in my cameras. (I use ch 1 for a lavalier, and 2 for room mic for audience questions.) Clip attributes show the 4 mono channels, routed to four audio tracks (normally I change this to 2 channels to 2 mono tracks, as the last two don't contain any audio). The weird thing is that the Meters in the Audio pane shows sound in only channel 1. On the Edit page timeline I get 4 mono tracks, with waveforms in the first two, as it should be. But the meter for track 2 shows no signal, and muting track 1 gives a total silence. Audio format is 48 kHz/24 bit PCM. The camera proxy files audio are AAC LC stereo (2 channels, channel layout: L R).

Unlinking all proxy files and deleting the clips from the Media Pool, dragging the clips in again and setting Clip attributes to Stero, Embedded ch 1 to track 1 L and embedded ch2 to track 1 R, and then linking to the camera proxies again gives the same result. Can't see a way to redefine audio for the camera proxy files.

Repeating with clip attributes 2 ch mono embedded to two mono tracks behaves the same.

Unlinking the proxy files "restores" the audio to the correct working in the media pool and on the timeline.

Importing a clip to a new bin, changing audio attributes to two mono tracks and generating a proxy from the clip (using auto resolution and DNxHR LB codec) works correctly in the media pool and on the timeline.

Is this a bug in 17 Studio beta 5, or is the problem with the camera proxy audio format? Any idea of how the Sony proxy files could be used without transcoding, possibly changing audio format parameters to 2 mono tracks (if at all possible in AAC LC) with some media management SW? ffmpeg?


Thanks. Again, this proxy workflow is a great feature.


Video Formats (from MediaInfo)

(X70)
Video: XAVC-L (long GOP) MXF, 3840x2160, 25p, var. bit rate 93.9 Mb/s, max 100, 4:2:0 8 bit (AVC, profile High@L5.1)
Audio: 4 channels mono, PCM, 48 kHz, 24 bits (frame rate 25.000 FPS (1920 SPF) ) (last 2 channels no sound)

(X70)
Camera Proxy
Video: MP4 file (format XAVC), 1280x720, 25p, var. bit rate 9 Mb/s, max 16, 4:2:0 8 bit (AVC, profile Main@L4)
Audio: 2 channels (stereo), AAC LC, 128 kb/s, 2 channels, channel layout: L R, 48 kHz frame rate 46.875 FPS (1024 SPF)

FS5 same audio formats, same behaviour.

(First post, I'll figure out the signature part later...)

Same problem in 17 beta 6 (on Win 10)

Same problem.