Blackmagic Forum

Start a new project, and injest a media clip, ( I have tried .MTS and .MP4).
Drag the clip onto the timeline and in the Record Viewer, click on Show Timecode overlays.
Place the Playline on the clip and note the value for V1 and A1. On my system, the two timecode values shown are nearly always different. Note that as the Audio and Video are linked and there are no red boxes indicating that the two components are displaced, therefore the two time code values should be identical.

I get a difference between 1 and 20 frames depending where I click on the clip. Moving the playline gives me a new but apparently random difference.

If i move the playhead position in one frame steps using the right arrow key, the frame difference between the audio and video increases by frame for each step. When the difference gets to 25, it the difference resets to zero.
Has this something to do with the newly introduced interlacing setting, which I do not understand?
John

I have not seen this behavior myself in Studio 17 for Windows.

My timelines always match the frame of my media. I do not work with interlaced media at all. My media always has actual timecode (not always true for the formats you listed).

I did set my timeline to match the media, and also set it up in a second project without matching the media. The Timecode random error is not affected by these interlace settings.
One of the clips had a free running time of day time code and the other clip had a time code which started at zero for each clip.
Both clips show a similar problem.
i suspect this is a 'bug'.

Seems to be working here.

In my window V1 is showing the source clips' original timecode. V2 shows the original length of the Adjustment clip before I stretched it out. A1 is the non timecoded audio I added later, though why it starts at 09:58:00:00 I have no idea. The burnt in timecode shows the correct values for the source clip and the timeline playhead position..

Charles
Thanks for your feedback.
My problem is far less complicated.
You have replaced the audio and changed he speed.

To replicate my problem, could you place the original clip with audio and video, on the timeline. Don’t change it or adjust or replace the audio but show the timecode overlay for v1 and A1. I see different values for the two tracks. They are 20 frames different. This difference changes as I reposition the playhead.
John

Here we are. A timecoded 50fps h264 camera clip on the timeline. No change with the relationship of the vid and audio timecodes wherever I place the playhead.

I also did a test with non timecoded AVCHD footage and the result is the same.

Charles
Thanks again for producing the examples. - interesting subjects.
Why do I always hit problems that no one else can replicate?
John

Subject wise, I make videos of Heritage railways for my YouTube channel.
As to the timecode problem I can only guess at a possible cause. Is the original audio at 44.1k? As Resolve automatically changes the sample rate to 48k on the fly, it might have an affect on the timecode leading to the discrepancy.

Charles
Thanks for the thoughts about audio sample rate.
I have just checked the spec for the two cameras I have been using. There are both 48 kHz.
I will update the video driver but I would be very surprised if this is the cause.
If I find a solution I will let you know.
Best wishes for your heritage film work.
John