Latest post Tue, May 12 2020 1:01 PM by Zingara. 17 replies.
Page 1 of 2 (18 items) 1 2 Next >
Sort Posts: Previous Next
  • Sat, May 9 2020 1:01 AM

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    video conversion for broadcast, Mastering.

    I've inherited a project that was startd with no thought to delivery, and it will be delivered to a broadcaster.  Firstly I am in a PAL region so 25fps is the norm and I am delivering an DNxHD, MXF OP1a, 1080i, 8bit, 25fps, with 8 embedded audio channels.

    This project has many different framerates 23.98, 24, 30, 29.97, but most is in 25fps (70%). This is of course something that happens a lot on shoots and probably a lot more in the current climate.

    The conversion's where done in Adobe Encoder to 25fps, but I am concerned about it not passing tech check.  There are duplicate frames on all the lower to higher frame rate conversions and bluring on movement on the higher to 25. The broadcaster in their supportive information recommends PixelStrings for all converstions, to get the best results. 

    I would love some advice, if anyone has used PixelSrings, also about the best and most cost efficent way to handle this situation.  Also what is the best postpathway for future season of the show. if mixed frame rates continue. 

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sat, May 9 2020 6:48 AM In reply to

    Re: video conversion for broadcast, Mastering.

    Hi. 

    It's a shame the conversion has already been done. 

    It's unlikely you can easily relink back to the original sources so your bridges are burnt I suspect. 

    You can't convert the already converted files. 

     

    The workflow would be to retsin the fps and use those sources direct in Avid. It can convert in the timeline and you have various parameters you can manipulate to improve those conversions. 

    Any that still fail QC you can extract the used sources and convert externally and the replace in the timeline

     

    This is not an uncommon workflow for many years here in the UK. 

     

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  Avid Certified Instructor VET

     

    QC/QAR Training - Understanding Digital Media - Advanced Files * Compression - Avid Ingest - PSE fixing courses and more

    All bespoke and delivered onsite at yours. Or delivered via hostred Zoom session.

     

    T 07581 201248 | E pat@vet-training.co.uk | W www.vet-training.co.uk |

     

  • Sat, May 9 2020 7:59 AM In reply to

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    Re: video conversion for broadcast, Mastering.

    Thank you for replying Pat. I think I can get the raws on another drive, but it there would be a lot of manual work as there are duplicate names ect, not an easy relink.  If I can get to the raws what do you suggest the Pixelstrings conversion or is AVID good enough?

    Also I want to get this straight for next time around, wonder if youcould clarify a bit.  If I get different frame rates do I transcode but keep the original frame rate and let Avid do the converting on the timeline.  Won't this compromise my performance, there is in fact a lot of drone, DJI, ozmo footage as well as phone etc.  Wouldn't I be better off transcoding everything to 25fps then conformin at the end?  I assume I would have a way to get back to the raws quickly in Avid. 

    I'm interested in the parameters you mention, is there somewhere you could point me to read or watch a tutorial on this?

     

     

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sat, May 9 2020 2:14 PM In reply to

    • Bruno M
    • Top 150 Contributor
    • Joined on Thu, Feb 11 2010
    • London, UK
    • Posts 701
    • Points 8,775

    Re: video conversion for broadcast, Mastering.

    Zingara:
    If I get different frame rates do I transcode but keep the original frame rate and let Avid do the converting on the timeline.  Won't this compromise my performance, there is in fact a lot of drone

    If I could chip into this conversation...

    I would recommend doing as you suggest... Link to the material and transcode, keeping the original resolution and frame rate.

    This will give the most options to experiment and see what works best with the tools you have inside Avid.

    Frameflex will work it's magic, resizing the clip and converting the framerate for you. The framerate conversion will be a speed change depending on the original fps of the source material. You'll see a temporal adaptor indication on the timeline (T) which tells you a motion effect has been applied to your clip. In the case of (say) 24 to 25fps, this will be approximately 4%.

    If you open up the motion effect editor you'll see this in the settings. You'll also see the method it's used to smooth out this footage due to the (inevitable) dropping or adding of frames that will have occurred. By default I think this is Blended Interpolated, but you can change the type from simple dupliicated field, all the way to Blended VTR. 

    You can try these various options and see which one is least objectional for your footage. If you're unsure what all these modes are, have a read of the Avid effects manual. Remember to use full (green) quality mode when viewing, otherwise you will not see the true nature of the effect applied. If you're working in an interlaced project (which I suspect you might be for the broadcaster delivery specs) there's progressive or interlaced source/record options available as well.

    There's one other mode you can try with your footage, and that's fluidmotion. You'll see it's greyed out by default, but if you promote the Motion Adaptor effect (to Timewarp) these options will be available. Fluidmotion creates whole new frames, so it might fix your problem with stutters/blurring, but it doesn't always work with some types of motion - introducing it's own weird artifacts on upredictable motion. It's also not real-time, and rendering can be fairly slow on long clips.

    If all these settings still do not produce a satisfactory result, the only other option you have is to play the source frame-by-frame in the project. You can do this by going to the source settings for your master clip and going to the Playback Rates tab.  You then need to change the setting to 'Project's Framerate' instead of 'Clip's framerate'  (and apply). Remember to refresh the sequence if your clip is already on the timeline.

    This will mean there's no duplicated/dropped frames and no motion interpolation. The trade-off is that your source clips will run faster on slower - determined by the difference between your project and source frame-rates. In the 24/25 fps scenario your clips will run approx 4% fast or slow, which may be OK for the material your using. Also be aware that any clip audio will be re-pitched slightly as well - it's approx three-quarters of a semitone, so speech and music will still sound OK, even if it is in a different key. You can always re-pitch the sound later on if necessary. Note that this technique will not really work if you're going from 24/25 to 29.97fps as that represents a whopping 20% speed change, and that is definitely visible!

    That's about the extent of the techniques (I've found) that can be employed in Media Composer. If none of this is satisfactory, you might want to look at some specialist plugins like (for after Effects) Re:Vision FX Twixtor, which has superior optical flow technology to Avid's Fluidmotion.

    HP Z800, HP G3 Studio, SonnetFusion RAID, Mojo DX, Symphony 2018.9, JVC DTV1910 HD tube monitor, HP Dreamcolor, Avid Artist Color, Avid Transport [view my complete system specs]
  • Sat, May 9 2020 3:15 PM In reply to

    Re: video conversion for broadcast, Mastering.

    In a PAL world, I would speed up all 23.976 and 24.000 fps source to 25fps. 50/59.94/60 etc you can keep the existing framerate and if needed pull the used footage and run it through standards conversion.

    Media Composer Symphony | PT Ultimate | Win10 HPZ | OSX MBP | ISIS5000 [view my complete system specs]
  • Sun, May 10 2020 6:18 AM In reply to

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    Re: video conversion for broadcast, Mastering.

    Thank you Bruno for your detailed reply it is very helpful.  I've also been adviced that it is best to transcode in a spereate project which is defined by what ever framerate I am working with, and then bring those clips into my 1080i 25fps project.  Have you found this necessary?

    Thanks again

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sun, May 10 2020 6:18 AM In reply to

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    Re: video conversion for broadcast, Mastering.

    Thank you Bruno for your detailed reply it is very helpful.  I've also been adviced that it is best to transcode in a spereate project which is defined by what ever framerate I am working with, and then bring those clips into my 1080i 25fps project.  Have you found this necessary?

    Thanks again

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sun, May 10 2020 9:26 AM In reply to

    • Bruno M
    • Top 150 Contributor
    • Joined on Thu, Feb 11 2010
    • London, UK
    • Posts 701
    • Points 8,775

    Re: video conversion for broadcast, Mastering.

    This is a technique that has been used to make it easier if you needed to link your sequence back to the original media.

    It used to be that MC couldn't relink across frame rates, thus making the separate projects necessary. At some point they added an option for linking across framerates, but I've had mixed results with it. There was also those who said they could relink more successfully if they kept the original framerate when transcoding, thus making separate projects unnecessary. 

    I've found that relinking in Avid can be a bit of a 'black art' and there's never one technique that fits all situations. Unless you're intending to link back to the original rushes (or going for an external grade, where they intend to link back to the camera originals) I don't think there's any advantage for you in the separate projects workflow.

    In all these situations, I always recommend a quick test to check the workflow, as it's not unusual for something that worked before to suddenly break with a new version of software.

    I think from what you've said about your situation, the material is being transcoded to the final resolution required before making the deliverables, so you don't need to think about relinking. 

    I did have a look at PixelStrings, and they seem to have a free option, where you can upload/download one clip to try out their service. If your speed conversions don't achieve the results you want, you could try them out and see what they can achieve.

    One final thought... If you're delivering an interlaced project (which is usual for 25fps broadcasters) I would recommend an external monitor that properly shows interlaced footage on screen. I still have a professional CRT for this purpose as many budget LCD/LED monitors don't display interlaced correctly, thus hiding some artifacts that can be produced in the individual fields when you do things like framerate conversions. I've seen some terrible interlaced combing effects on some Sky channels, and even some budget adverts with reversed fields.

    HP Z800, HP G3 Studio, SonnetFusion RAID, Mojo DX, Symphony 2018.9, JVC DTV1910 HD tube monitor, HP Dreamcolor, Avid Artist Color, Avid Transport [view my complete system specs]
  • Sun, May 10 2020 4:51 PM In reply to

    • tpowell
    • Not Ranked
    • Joined on Wed, Dec 10 2014
    • Posts 50
    • Points 595

    Re: video conversion for broadcast, Mastering.

    For the drone shots, b-roll where audio sync is less important, artsy shots, etc., setting the source settings to play back at the project rate gives you footage with a speed change, but without the need for a converstion that leads to duplicated fields/frames or blurred frames. This works especially well for drone shots, as I find myself changing the speed quite often, and I can then work in even percentages for the speed changes. I am just finishing a 2-hour documentary with every flavor of frame rate imaginable, and I would say probably 60% of my footage has this speed "conversion" (by not converting), which is not noticeable in the cut. About 25% of the rest was shot with the "A" camera at the deliverable rate, leaving only a small percentage of footage that must be converted. As I edit with the transcoded material, if I notice that the action seems to be running fast or slow, or where dialogue or audio sync is important, that's when I would go back to the pre-transcoded shot for the conversion. It sounds harder than it is.

  • Sun, May 10 2020 9:30 PM In reply to

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    Re: video conversion for broadcast, Mastering.

    Thank you that is all great to know. I will definately try setting the source to playback at project rate, and work each clip as needed.  I think I have my head around how to treat all these different frame rates now, but I'm wondering about the transcoding.  I know I should be retaining the frame rate and the resolution, but am wondering about the codec.  Does this matter at all?  Do I just make everything at DnxHD, 36 or 120?  Should I transcode at a codec I grade at or do I re-link and upres/ conform?  As mentioned above relinking can be a nightmare, but as I can get so much footage I need to optimise for offline editing as well.  Is there a paper I can read about this issue?

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sun, May 10 2020 9:40 PM In reply to

    Re: video conversion for broadcast, Mastering.

    Once re-linked transcode at finishing codec quality. You don't want to have to relink again!

    Also you want to judge the quality of the frame rate conversions at finishing quality.

     

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  Avid Certified Instructor VET

     

    QC/QAR Training - Understanding Digital Media - Advanced Files * Compression - Avid Ingest - PSE fixing courses and more

    All bespoke and delivered onsite at yours. Or delivered via hostred Zoom session.

     

    T 07581 201248 | E pat@vet-training.co.uk | W www.vet-training.co.uk |

     

  • Sun, May 10 2020 10:22 PM In reply to

    • Zingara
    • Not Ranked
    • Joined on Thu, Oct 8 2009
    • Melbourne, Australia
    • Posts 47
    • Points 580

    Re: video conversion for broadcast, Mastering.

    Hi Pat, do you mean cut at finishing codec quality? Or just have the mixed frame rates at this quality, (your right won't be able to jusdge quality if it's at a lowres).  Worried about the impact on MC while cutting if it all at 120 or 185.

    Mac OS 10.15.5 Processor 3.2 GHz 16_Core Intel Xeon W Graphics AMD Radeon Pro Vegas II 32 GB [view my complete system specs]
  • Sun, May 10 2020 11:04 PM In reply to

    • tpowell
    • Not Ranked
    • Joined on Wed, Dec 10 2014
    • Posts 50
    • Points 595

    Re: video conversion for broadcast, Mastering.

    Depending on the type of project, for documentaries I cut at the finishing resolution. For the miles of interviews, I don't even transcode them, but use the linked file. When I cut them into the timeline, I just render the piece that is in the timeline. It might be only 5 or 6 seconds of a 20-minute (or more) interview that ends up on the video track in the timeline. If there is no effect to render, I just drop on a basic color grade effect that I keep in the bin. This allows me to pile graphics, etc. over it without AMA choking and saves a lot of time and diskspace. For shots where I might be stacking a lot of effects or manipulating them a lot, I usually transcode in full project resolution. For other clips, I might still use the AMA render trick. At HD, most shots render quickly and I hardly notice it. The diadvantage is that if you do anything else to the shot, or change a layer underneath it, you have to render it again, but my super long clips, usually interviews, are typically on V1. Not a workflow for everyone, but it has been working for me since AMA started to really be useful.

  • Mon, May 11 2020 10:10 AM In reply to

    Re: video conversion for broadcast, Mastering.

    Zingara:

    Hi Pat, do you mean cut at finishing codec quality? Or just have the mixed frame rates at this quality, (your right won't be able to jusdge quality if it's at a lowres).  Worried about the impact on MC while cutting if it all at 120 or 185.

    Yes HD broadcast (here in the UK) is typically DNx185x and any half decent system should be able to manage that.

    This is finishing/online. 

    Its normal to transcode all you content in the final sequence to the finishing codec at the start of the online as it resolves so many issues and exposes any problesm that its better to resolve then rather than at the export stage.

    Of course as a finishing system you also would expect an IO box and playout to a decent broadcast monitor so you can actually see the quality of the content you are finishing and that would include the frame rate adjustments.

     

     

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  Avid Certified Instructor VET

     

    QC/QAR Training - Understanding Digital Media - Advanced Files * Compression - Avid Ingest - PSE fixing courses and more

    All bespoke and delivered onsite at yours. Or delivered via hostred Zoom session.

     

    T 07581 201248 | E pat@vet-training.co.uk | W www.vet-training.co.uk |

     

  • Mon, May 11 2020 10:11 AM In reply to

    Re: video conversion for broadcast, Mastering.

    Zingara:

    Hi Pat, do you mean cut at finishing codec quality? Or just have the mixed frame rates at this quality, (your right won't be able to jusdge quality if it's at a lowres).  Worried about the impact on MC while cutting if it all at 120 or 185.

    Yes HD broadcast (here in the UK) is typically DNx185x and any half decent system should be able to manage that.

    This is finishing/online. 

    Its normal to transcode all you content in the final sequence to the finishing codec at the start of the online as it resolves so many issues and exposes any problesm that its better to resolve then rather than at the export stage.

    Of course as a finishing system you also would expect an IO box and playout to a decent broadcast monitor so you can actually see the quality of the content you are finishing and that would include the frame rate adjustments.

     

     

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  Avid Certified Instructor VET

     

    QC/QAR Training - Understanding Digital Media - Advanced Files * Compression - Avid Ingest - PSE fixing courses and more

    All bespoke and delivered onsite at yours. Or delivered via hostred Zoom session.

     

    T 07581 201248 | E pat@vet-training.co.uk | W www.vet-training.co.uk |

     

Page 1 of 2 (18 items) 1 2 Next >

© Copyright 2011 Avid Technology, Inc.  Terms of Use |  Privacy Policy |  Site Map |  Find a Reseller