FLAC, MKV & FFV1 - Issues

Firstly I want to say to whoever dev wise pushed FFV1 with interlaced export into the last few updates. I bloody tip my hat , Resolve is now the first industry NLE to have complience with current SD archives and production with 3rd party tools.

But there is a few issues:

- FLAC audio within the context of using anything inside the MKV wrapper when dropped onto the timeline it just freases up, and we have to de-mux the file and add the audio track in seprately for it to be fluid.

- FLAC encode, where is it?

- PAR, it always sets as Custom and needs manual correction in clip attributes.

- The export page defaults to 8-bit 4:2:2 when source is 10-bit 4:2:2, slight niggle issue but it does trip people up for doing 10-bit in and 10-bit out to suddenly find there export is now 8-bit.

- No 720x512 NTSC and 720x608 PAL IMX options.

(Its not a big ask too add IMX50 as there is already a MPEG-2 encoder, but it would just would be nice to have the standard IMX resolution options for SD archives with VBI space present like those from the decode projects (vhs-decode etc) export tools and BBC archives rather then manually having to deal with it.)

- FLAC audio within the context of using anything inside the MKV wrapper when dropped onto the timeline it just freases up, and we have to de-mux the file and add the audio track in seprately for it to be fluid.

Which Resolve version and operating system?

If the host hangs please include a link to diagnostic logs.

Instructions to generate logs are provided in the FAQ: viewtopic.php?f=21&t=90190#16

FLAC encode, where is it?

On the Deliver page select the Audio Only preset. On the Audio Tab select FLAC as the Format and the Codec preference will also be set to FLAC.

For Video exports, select MKV as the Format on the Video tab. On the Audio Tab select FLAC as the Codec preference. FLAC is also available for the MP4 format with both h.264 and h.265 codec.

Hi,

I'm echoing harrypm's sentiment that it's a big step for a whole category of users to get MKV/FFV1 support in Resolve, and I'm grateful for that.

I've been trying out FFV1 files since it became available in v18 and happy with the results except for one thing: performance issues when loading up files.

For now, I'm working mainly with SD interlaced MKV/FFV1/PCM files (from digitized tapes).
Those files don't have a huge size or bitrate (typically around 70Mb/s).
However, when dropping one of those in Resolve's Media Pool, it can take minutes before it is imported (meanwhile, UI is frozen). Then when it's finally in, playback is very laggy for maybe 20 seconds and then it all becomes rather smooth.
Just tested in 19.0.1 build 6, loading a file from a network share. Resolve gave up after a 5-minute freeze and didn't load anything. Then I try again and it finally loads after a few minutes. It works a bit better on fast local storage but still quite slow. Logs (attached) don't seem detailed enough to explain what's going on. It only shows that it's giving up loading after 5 minutes.

Code: Select all

SendSync() timed out in 300010 ms

Then during playback there are a lot of

Code: Select all

Timeout waiting for interop lookahead (AVSyncCount = 31)

Had tested studio and non-studio v18 before, same results.
Mainly testing on Windows, but tried MacOS as well.

Loading up a the same video converted to ProRes (slightly smaller file), from the same storage location, is instant.

Since I don't see major performance issues once the file is loaded for good, there doesn't seem to be a ressource problem with FFV1 decoding.
The same source file opens and plays instantly in VLC, MPV or Shotcut.

Therefore, there seems to be something about opening / indexing MKV content, or excessive caching.

Has this been noticed/reported by others ? Is it only me?

I confirm the same issues with the latest 19.1.
I'd be interested in hearing feedback from other users, or explanations from BM people?

Same issue on v20 this is very depressing really I still have to export FFV1/PCM from tbc-video-export for use with resolve.

I think MKV and FFV are bad choices for workflow, period.

I don't have as many problems with FLAC per se (not in a container). But Resolve is made to use 48kHz / 24-bit uncompressed WAV files, and I find there's zero problems if you stick with that.

I agree that Resolve should support all the various IMX delivery formats.