Lee Wilson
Veteran
Seems ok to me.
EOS 5D MK II workaround: Converting 30p into 24p/25p
- Thread starter Bebel
- Start date
Seems ok to me.
My wife tends to find footage with a high shutter speed to be "fast", though it isn't. I can see the same happening with a low shutter, making it seem slow to some, though it isn't.
So, are there any tests showing the 5DM2 retimed (preferably to 24p) in situations where artifacts are likely (many similar items in frame or multiple moving items in different directions, or whatever)?
It looks like we are now planning to shoot our doc with a pair of D90s for main camera (swapping due to heat issues). It wouldn't cost me much more to go with the 5DM2, but I want 24p... test footage of a baby thats staying pretty still doesn't convince me I can successfully retime the overwhelming majority of my footage.
So, are there any tests showing the 5DM2 retimed (preferably to 24p) in situations where artifacts are likely (many similar items in frame or multiple moving items in different directions, or whatever)?
It looks like we are now planning to shoot our doc with a pair of D90s for main camera (swapping due to heat issues). It wouldn't cost me much more to go with the 5DM2, but I want 24p... test footage of a baby thats staying pretty still doesn't convince me I can successfully retime the overwhelming majority of my footage.
Lee Wilson
Veteran
I will tell him of your concerns, but I don't think he is going to be happy about it.
filmmaker's gang
Carbonite Member
doesn't retiming affect the footage?.. slowing the motion?
Gordon Prince
Well-known member
I didn't understand this system of retiming either. Isn't it the same as overcranking?
Lee Wilson
Veteran
No not at all, you are simply changing the frame rate.
10 seconds @ 30 fps = 10 seconds.
10 seconds @ 25 fps = 10 seconds.
10 seconds @ 1 fps = 10 seconds.
And so on . . . .
Gordon Prince
Well-known member
Okay, but what does retiming mean? 25 fps = less 5 frames. Any drop? Nope. What's up?
It's probably too simple for a few. But ask to everybody, I bet 4/5 don't follow what retiming is.
It's probably too simple for a few. But ask to everybody, I bet 4/5 don't follow what retiming is.
bjdowns
Member
I'm no expert, but I believe that retiming actually renders missing frames using interpolation algorithms in software suites. After Effects can do this, as well as the plug-in, Twixtor.
Lee Wilson
Veteran
The software generates 25 frames from the 30 frames by analysing the pixel information in each frame.
Lee Wilson
Veteran
No, nothing is being sped up or slowed down.
Maybe I should do a visual example to help explain . . . . .
Last edited:
Thanks for that Lee!
DL'd the footage and it looked quite good except for some horrific artifacts with people moving past each other in multiple directions at about 1 sec in 5D MkII 30p to 25p test 2. I could barely see the artifacts in the small vimeo clip but I could tell something was wrong without pausing to pixel peep with the hd upload. Ouch... truly bizarre if only for a few frames at a time.
I am not sure I can deal with that on my primary camera... but the rest of it definitely had higher image quality than the D90. I wonder if a different algorythm would fix those tiny bits. Or if some post technique might clean it up...
Hypothetically, what would the workflow be?
Retiming and saving in a decent editting codec for the entire footage shot for a feature length doc isn't my idea of a fun time!
Just edit and then retime the final project? Somehow save my edits and create a new project using them with the retimed footage? Maybe render and retime each clip on the timeline of a rough-cut and work from there?
Lee Wilson
Veteran
Yep, they are typical of the kind of artefact this technique can throw up.
But bear in mind of all the many many parameters (all adjustable over time) - I adjusted none, I just stuck it on the defaults, a better set up might yield much better results.
Also Twixtor is said to be a superior product to the After Effects implementation (which I used).
Work as normal, when finished retime the whole piece to 25/24 (or whatever) - go through and check for any weirdness or artefacts - and clean them up.
With which tools?
Lee Wilson
Veteran
That depends on the kinds of issues to be addressed, the subject matter, your expectation, your time constraints and so on.
Canon 5D Mark II, 30p to 24p Conversion Workflow
Canon 5D Mark II, 30p to 24p Conversion Workflow
Superb 30p to 24p Workflow
1. Create copy of clip so you'll have two clips, one to convert to 24p and one to preserve audio.
2. Open Cinema Tool (part of Final Cut Studio), File, "Open Clip", choose "Conform", specify "23.98" to conform to.
Explanation: This keeps the same number of frames in the clip, it only changes the timebase from 30fps to 24fps, essentially creates overcranked footage by 6 frames, (desirable on some shots). As a result this makes the clip longer and slows the audio down which is undesirable where audio is important. At this point you've already created a copy of the original clip therefore preserving the original audio which we'll relink later in Final Cut.
3. Now we'll convert the clip to a desirable format for the workflow and effectively speed the clip back up so you get desirable 24p realtime results. Using Compressor 3 convert the clip to any of the following settings:
* Apple Pro Res
* Apple Intermediate Codec
* DVCPRO
Important: Make sure that no matter which codec you use that it remains as a 23.98 fps timebase.
Now open the inspector window so we can do some tweaking. Under "Frame Controls" tab, click the button to the right of "Frame Controls:" to enable this feature. Once enabled, select "On" for "Frame Controls:" Underneath the "Retiming Control" section is where we'll make changes. For "Set Duration to:" click the radio button where it will allow us to put in a percentage. The magical number we'll want to put in here is 79.996%, then depending on how well you want the footage to look also taking into consideration the time it will require to compress it choose the desired quality under "Rate Conversion:". I choose, "Best (High quality motion compesnation)" to get superb results, however this increases the compression time.
Now, what have we done here? We've converted the unusable H.264 format into a format we can edit in and sped the footage back up to original duration using Apple's Optical Flow Technology.
4. Now take the treated clip into Final Cut insuring the timebase is 23.98, delete the audio track and add the audio from the copy of the clip we made. Now relink and presto!
I've extensively tested this and find it to be the best way to convert 30p to 24p for the time being, or atleast until and hopefully Canon comes up with a firmware to address the issue.
Additional Tips: If you have multiple clips to treat, in Cinema Tools, choose "Batch Conform" locate one file where all the files are located. Then setup batch conversions in compressor, if you have a quad core or 8 core configure Q master to take advantage of all cores otherwise it will take longer.
One final note, depending on the specific needs of your project you may need to treat many individual clips or take your finished project (of course h.264 has been converted to an editable format) and follow the steps above to get great results. I've tested a 9 minute clip and was able to complete the compression on an 8 core in one hour and a half.
Bests,
Denver Riddle
Canon 5D Mark II, 30p to 24p Conversion Workflow
Superb 30p to 24p Workflow
1. Create copy of clip so you'll have two clips, one to convert to 24p and one to preserve audio.
2. Open Cinema Tool (part of Final Cut Studio), File, "Open Clip", choose "Conform", specify "23.98" to conform to.
Explanation: This keeps the same number of frames in the clip, it only changes the timebase from 30fps to 24fps, essentially creates overcranked footage by 6 frames, (desirable on some shots). As a result this makes the clip longer and slows the audio down which is undesirable where audio is important. At this point you've already created a copy of the original clip therefore preserving the original audio which we'll relink later in Final Cut.
3. Now we'll convert the clip to a desirable format for the workflow and effectively speed the clip back up so you get desirable 24p realtime results. Using Compressor 3 convert the clip to any of the following settings:
* Apple Pro Res
* Apple Intermediate Codec
* DVCPRO
Important: Make sure that no matter which codec you use that it remains as a 23.98 fps timebase.
Now open the inspector window so we can do some tweaking. Under "Frame Controls" tab, click the button to the right of "Frame Controls:" to enable this feature. Once enabled, select "On" for "Frame Controls:" Underneath the "Retiming Control" section is where we'll make changes. For "Set Duration to:" click the radio button where it will allow us to put in a percentage. The magical number we'll want to put in here is 79.996%, then depending on how well you want the footage to look also taking into consideration the time it will require to compress it choose the desired quality under "Rate Conversion:". I choose, "Best (High quality motion compesnation)" to get superb results, however this increases the compression time.
Now, what have we done here? We've converted the unusable H.264 format into a format we can edit in and sped the footage back up to original duration using Apple's Optical Flow Technology.
4. Now take the treated clip into Final Cut insuring the timebase is 23.98, delete the audio track and add the audio from the copy of the clip we made. Now relink and presto!
I've extensively tested this and find it to be the best way to convert 30p to 24p for the time being, or atleast until and hopefully Canon comes up with a firmware to address the issue.
Additional Tips: If you have multiple clips to treat, in Cinema Tools, choose "Batch Conform" locate one file where all the files are located. Then setup batch conversions in compressor, if you have a quad core or 8 core configure Q master to take advantage of all cores otherwise it will take longer.
One final note, depending on the specific needs of your project you may need to treat many individual clips or take your finished project (of course h.264 has been converted to an editable format) and follow the steps above to get great results. I've tested a 9 minute clip and was able to complete the compression on an 8 core in one hour and a half.
Bests,
Denver Riddle
Small Correction
Small Correction
Just wanted to make a small correction to setting duration. I had indicated that 79.996% was the magic number when in fact depending on the length of the clip it can very slightly. So the safest way is to take the original audio into the final cut pro timeline, go the last frame and read the duration HH:MM:SS:FF (for example 01:08:01:06) then in your retiming control, click the middle "Set Duration to:" radio button and set the matching timecode duration.
Note: It's important when you're determining the length of the audio clip that the final cut pro timeline/sequence is set 23.98 timebase, if it's on anything else you won't be able to get the right reading.
Hope that helps, let me know if you've found this beneficial.
Bests,
Denver
Small Correction
Just wanted to make a small correction to setting duration. I had indicated that 79.996% was the magic number when in fact depending on the length of the clip it can very slightly. So the safest way is to take the original audio into the final cut pro timeline, go the last frame and read the duration HH:MM:SS:FF (for example 01:08:01:06) then in your retiming control, click the middle "Set Duration to:" radio button and set the matching timecode duration.
Note: It's important when you're determining the length of the audio clip that the final cut pro timeline/sequence is set 23.98 timebase, if it's on anything else you won't be able to get the right reading.
Hope that helps, let me know if you've found this beneficial.
Bests,
Denver
Elton
Veteran
Hey Denver,
Does this method avoid adding interpolated frames to the footage? It seem like its the reverse of doing a 30 to 24p conversion with the frame controls turned on and quality set to "high quality motion compensated", and duration set to 100%.
I get pretty good results this way, but you do get interpolated/blended frames that are sometimes noticeable in the footage.
Have you stepped through your footage to see if you get occasional interpolation frames?
Thanks for posting!
Does this method avoid adding interpolated frames to the footage? It seem like its the reverse of doing a 30 to 24p conversion with the frame controls turned on and quality set to "high quality motion compensated", and duration set to 100%.
I get pretty good results this way, but you do get interpolated/blended frames that are sometimes noticeable in the footage.
Have you stepped through your footage to see if you get occasional interpolation frames?
Thanks for posting!
Response
Response
You know that's a really good question, I don't know that I could provide a good answer for you other then I suppose the concept of speeding footage back up to a certain duration is better than converting from a higher frame rate to a lower frame rate using frame controls. Someone might have a better answer but what I can tell you is I'm achieving near perfect, if not perfect results. I stepped through the footage and there's only the slightest motion blur on moving shots/action but no more motion blur then what you expect to be there. Of course without shutter speed control you can't ensure the correct exposure timing per frame, my guess is 1/60 shutter speed should be about right, then convert to 24p should yield in essence 1/48 shutter speed, someone can correct me if I'm wrong on that, I've always understood double the shutter speed for frame rate or 180 degrees angle.
You should treat a clip of footage both ways and step through each frame, compare frame for frame and see which yields better results, I'd be very interested in your findings and I'm sure a lot of people would be as well. That way I'd know if the additional steps are necessary.
Bests,
Denver
Response
You know that's a really good question, I don't know that I could provide a good answer for you other then I suppose the concept of speeding footage back up to a certain duration is better than converting from a higher frame rate to a lower frame rate using frame controls. Someone might have a better answer but what I can tell you is I'm achieving near perfect, if not perfect results. I stepped through the footage and there's only the slightest motion blur on moving shots/action but no more motion blur then what you expect to be there. Of course without shutter speed control you can't ensure the correct exposure timing per frame, my guess is 1/60 shutter speed should be about right, then convert to 24p should yield in essence 1/48 shutter speed, someone can correct me if I'm wrong on that, I've always understood double the shutter speed for frame rate or 180 degrees angle.
You should treat a clip of footage both ways and step through each frame, compare frame for frame and see which yields better results, I'd be very interested in your findings and I'm sure a lot of people would be as well. That way I'd know if the additional steps are necessary.
Bests,
Denver