Latest post Tue, May 16 2017 10:53 AM by Wohlbefinden. 5 replies.
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  • Fri, May 5 2017 7:40 AM

    • Erik
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    • Joined on Thu, Oct 5 2006
    • Austin, TX
    • Posts 199
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    AMA linked file's timecode does not match source timecode.

    I'm using MC 8.8.2 on Win10.

    I'm AMA linking MP4 files that were recorded on a GoPro Hero Session in UHD. I edited a few of these AMA clips into a sequence and exported a AAF file. I imported the AAF into Resolve choosing options to work with the original source media and it balked that there was a mismatch in the timecodes between the starting and ending timecodes in the AAF and the source media, it shows the timecode that Avid put and the timecode of the source...and they were way off.

    First I thought I had screwed something up and double-checked everything, including the project settings (source is 29.97p and the project is 29.97), re-exported the AAF and the same thing occurred. I looked at the source file's metadata using the MediaInfo utility and it lists the starting timecode matching what Resolve was seeing. I imported the clip into Premiere Pro and the timecode also matches what Resolve sees.

    Looking in the Avid bin it is showing a starting timecode that is way off.

    For example, Premiere shows one clip having a starting and ending timecodes of:

    10:04:41:04 - 10:06:01:20

    While Avid shows it as:

    10:25:32:06 - 10:26:52:23

    A difference of 20:51:02

    To make matters worse, this difference in time isn't consistent from clip to clip.

    A second clip shows a timecode in Premiere as:

    10:45:02:04 - 10:46:33:14

    but in Avid as

    11:07:16:21 - 11:08:48:02

    A difference now of 22:14:17

     

    I can't see anywhere that Avid might be getting this incorrect timecode. 

    I can use the Modify Clip to change the start timecode to be correct, and then exported AAF links properly back to the source media, but this is time consuming. 

    What could be the problem with Avid properly reading the clip's timecode?

    MC 2018.4 Dell Precision 7710 mobile workstation, 64GB of memory, Xeon E3-1535M v5 @2.9Ghz, Nvidia Quadro M5000m. Running Win10 64bit. MC 2018.5 Asus... [view my complete system specs]
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  • Fri, May 5 2017 4:29 PM In reply to

    • Erik
    • Not Ranked
    • Joined on Thu, Oct 5 2006
    • Austin, TX
    • Posts 199
    • Points 2,340

    Re: AMA linked file's timecode does not match source timecode.

    Doing some more investigation. I opened a project containing MP4 files from a different source, these were video clips that were transcoded to h.264 and don't have embedded timecode. They are 29.97 1080p clips

    I attempted to do an AAf export of sequence with a couple of these clips. Importing the AAF into Resolve, it gave an error on one of the clips about the timecode, and showed that the clip in the AAF from Avid was one frame longer than the source.

    Sure enough several of the clips in Avid linked via AMA have durations that are slightly different from the source video. Premiere and Resolve show the correct duration.

    You can also see as the Source Browser parses the clips, that some of the durations are incorrect

    I attempted to import one of these clips rather than linking and Avid imported it and created the Avid media but still showed the incorrect duration.

    I went to a different system, one that is running MC 8.8.1 and Win7. Created a new project and AMA linked one of these clips and again it shows the incorrect duration.

    I then used Adobe Media encoder, which showed the correct clip duration, to transcode one of these clips (one that was showing the wrong duration in Avid) to DNxHD. Then AMA linked to that clip in Avid...it now shows the correct duration.

    As a further test I added this new clip to a sequence exported an AAF and opened it in resolve and linked it back to the original Mp4 without a problem.

    Using Adobe Media Encoder again, I transcoded one of the GoPro clips that Avid was showing with whacky timecodes, to DNxHR, then AMA linked it back into its project. Sure enough, Avid now shows the correct timecode values for that specific clip.

    So for whatever reason, Avid is not parsing h.264 files correctly that use the Quicktime importer. I have the latest Quicktime version installed 7.7.9 which is listed on the Media Composer compatiblity grid for MC 8.8.2.

    This is pretty frustrating as I can't trust Avid to read the correct timecode or duration when importing or linking h.264 clips that use the Quicktime importer. While a workaround seems to be to transcode clips using Adobe Media Encoder before importing or linking, it's not optimal and is time consuming. I could ignore it and transcode everything in Avid and then export an AFF to Resolve for color color and just work with the Avid media...but again, not optimal as I'm working from clips that have already had one round of encoding and will have another round of encoding coming out of Resolve.  

    MC 2018.4 Dell Precision 7710 mobile workstation, 64GB of memory, Xeon E3-1535M v5 @2.9Ghz, Nvidia Quadro M5000m. Running Win10 64bit. MC 2018.5 Asus... [view my complete system specs]
  • Fri, May 5 2017 5:28 PM In reply to

    Re: AMA linked file's timecode does not match source timecode.

    I ran into a problem with AMA giving the wrong duration for H.264 a while back, in MC 6 I believe.

    I found MC had too long a duration by some percentage of the clip's length. What I saw was that MC was appending duplicate frames to the begiing or end of the clip. I could clearly see the repeating identical frames.

    I would check to see if you see the same.

    Also know that MC uses duration and TC to relink clips. So if a future vesion of MC fixes this bug and you happen to have your media go offline (let's say from not having the source drive powered up and connected when opening MC) you will not be able to relink to your clips.

    Good luck!

    "When I spent 60k on a discreet edit digisuite system 10 years ago someone came up to me to offer fcp 2, I said it was a scam too." -Ric

  • Fri, May 5 2017 5:46 PM In reply to

    • Erik
    • Not Ranked
    • Joined on Thu, Oct 5 2006
    • Austin, TX
    • Posts 199
    • Points 2,340

    Re: AMA linked file's timecode does not match source timecode.

    Thanks. I'll check to see if there are extra frames, but it may still not explain why Avid seems to be pulling a completely different timecode for some clips.

    I did find an Avid KB article regarding Quicktime, specifically about Avid's need for Quicktime while everyone was uninstalling a while back it due to security concerns. They mentioned they are working towards not having dependencies on Quicktime anymore for import. And mentioned releasing an update later this year. Perhaps this will address this particular problem, whenever they actually release said update. I guess until then I'll just add extra time to my workflow by transcoding or use Premiere.

     

     

    MC 2018.4 Dell Precision 7710 mobile workstation, 64GB of memory, Xeon E3-1535M v5 @2.9Ghz, Nvidia Quadro M5000m. Running Win10 64bit. MC 2018.5 Asus... [view my complete system specs]
  • Sun, May 7 2017 12:19 PM In reply to

    Re: AMA linked file's timecode does not match source timecode.

    Also, I beleive we get one tech support call per month now. Maybe they can shed some light on this, or create a case to get it fixed.

    "When I spent 60k on a discreet edit digisuite system 10 years ago someone came up to me to offer fcp 2, I said it was a scam too." -Ric

  • Tue, May 16 2017 10:53 AM In reply to

    Re: AMA linked file's timecode does not match source timecode.

    I just had a similar problem on my Windows MC: inputting through Source Browser gave me linked clips all with the same source timecode of 00:00:00:00, making a timecode based autosync impossible. Using the Media Tool I had the same problem unless I imported copies in MXF OP1A format, but even that didn't work every time.

    The video files in question are DNxHD 1080p copies of 2k Apple prorez made by an Arri Alexa.

     

    The solution was to:

    Create new project

    let Avid make an Avid MediaFiles/MXF/1 folder by importing a .png into a bin

    copy video files into "1" folder

    delete the reference files (pmr, MOB)

    let Avid scan the disk again

    open the MediaTool and scan the disk in question with all projects selected

    drop files into a new bin

     

    and the original source timecode is there. Every other procedure led to the 00:00:00:00 timecode. Is this a ProRes/Windows issue? I got the files from a DIT and am not sure how he copied them, but he had no problems with TC on on his  Mac Avid MC 8.

     

    Specs: Avid MC 8.7 Windows 7 Pro, Quadro k2200, 32GB RAM

     

    Avid MC 8.4, Windows 7, Intel i7-3770 CPU@3.4 GHz, 64 Bit, Nvidia Quadro K2200 [view my complete system specs]
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