Save yourself frustration: Use “editing” formats when editing
We occasionally get support calls from people that are experiencing strange lagging, stuttering, or freezing of ScreenFlow when they are trying to edit their projects. One of the first questions we ask (after “did you spill a cold beverage on your keyboard?”) is:
Do you have imported video in your projects; and if so what format/codecs are those imported videos?
Editing formats vs. delivery formats:
In the world of digital video there are formats that are designed for editing, and then there are formats that are designed for delivery (or distribution).
If you use a “delivery” format in an editing program (such as ScreenFlow), it can behave distinctly BADLY, causing all sorts of problems that, if you don’t know what’s going on, can appear to be caused by your editing program.
When editing digital video, non-linear editing programs work by accessing and changing the individual frames of that digital file. So, ideally, all the data or information for each frame should be easily accessible to the editing program. This can result in large, uncompressed files with lots of video data.
Alternatively, when delivering a digital video, you want your file to be compressed and as easy as possible for your video player to access, read and display.
To handle these two scenarios, there are two distinct codec types: Intra-frame codecs (best for editing) and Inter-frame codecs (best for delivery).
Intra-frame codecs store all the video information for each frame on every individual frame. As the name suggests, you are basically encoding each separate frame as its own picture. Inter-frame codecs, on the other hand, rely on information in preceding and occasionally upcoming frames. Inter-frame codecs take advantage of redundant information on neighboring frames, and save space by storing the changes between frames.
Look at me getting technical:
To get a little technical, here’s how it works:
Inter-frame codecs use three different types of video frames: I-frames, P-frames, and B-frames.
I-frames, also known as keyframes, contain all the information for a frame on each individual frame. Intra-frame codecs use I-frames exclusively. Every frame is encoded and decoded individually. Inter-frame codecs, alternatively, use very few I-frames. The reason is that the more I-frames you have, the larger the file is, and the goal of delivery codecs like H.264 or WMV is to compress the video as much as possible.
P-frames, or delta frames, contain only the changes from the last frame, making them much smaller in size than I-frames because they are only storing a fraction of the data. However, in order to view a P-frame, the computer has to go back to the last I-frame, and decode every single frame up until that P-frame. Some highly compressed video formats can go 200 or more frames between I-frames. So, if you try to edit video with P-frames, your computer has to go back to the previous I-frame and decode all 200 frames just to view current P-frame, which is a lot of processing, and can result in stuttering or even crashing.
B-frames, or bi-directional frames, are like P-frames, but instead of just saving the changes from the previous frame, they also take information from the next frame. For editing programs not able to handle these types of frames, this can result in frames being displayed out of order.
Because of all the processing needed to decode previous and next frames, Inter-frame video can cause a lot of problems when imported into a non-linear editing program such as ScreenFlow, iMovie or even Final Cut Pro for editing.
You might see
- Slow searching for and decoding of frames
- Frame-accuracy problems
- Crashing or freezing
- Strange artifacts or blocking on your video
- Error messages or displaying black video
What formats should you use?
Here are some common video formats that you should not edit with (i.e. these use Inter-frame codecs and are better for final delivery):
- XviD, DivX, 3iVX
- MPEG-2
- MPEG-4 / H.264
- WMV
- RealVideo
- VP6, VP7, VP8
Here are some common Intra-frame formats that are good for editing:
- Uncompressed (file sizes can be very large, though)
- ProRes
- DV
- M-JPEG
- JPEG2000
- Animation
- x264 lossless mode
How to check the format of your video:
If you don’t know what format your video is, you can easily check it by opening it in QuickTime. Go to “Windows >> Show Movie Inspector” and then under the heading for “Format,” it will list the codec (DivX, H.264, DV, etc).
How to convert from a delivery to editing format:
If you have video in an Inter-frame codec that you would like to edit, then you should convert it to an Intra-frame codec first.
You could, of course, use Episode, which is professional-quality multiformat transcoding software also produced by Telestream.
Or if you have just one or two videos you need to convert, it might be more cost-effective to do a internet search for a software encoding product that will handle just the format you need to convert.
That’s basically it. So if you find yourself struggling to edit a video in ScreenFlow, check your imported videos, and make sure you’re using editing formats.
19 Responses to “Save yourself frustration: Use “editing” formats when editing”
April 10th, 2012 at: 6:52 pm
Wouldn’t it make sense for Screenflow to check at point of ingest the video format and throw a warning to make editors aware of this issues?
Whenever we face this problem, we typically run any inter-frame videos through Handbrake (at a very high bitrate, to be on the safe side) or Compressor to create h.264 files for editing. This is especially true for Flash (FLV) video, which has given us grief in Screenflow in the past.
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Lynn Elliott Reply:
April 23rd, 2012 at 4:35 pm
Thanks Veit,
YES, that *would* be a good feature to add to ScreenFlow. Though I’ll have to ask our engineers how easy/feasible that is…
Thanks for your input on how you handle this problem. What bitrate do you typically change it to? And do you touch/change the number of keyframes?
Thanks again, as always.
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Conny Reply:
July 5th, 2012 at 7:02 am
You really should do something about this. I´m quite technical but have never been into video (I record and produce music) and all these different files and bitrates and shit is making me confused. I just want to export my movie I´ve made with Screenflow and now I´ve been sitting here all fuckin´afternoon trying to understand why the program crashes every time I try to export the movie. FRUSTRATED!
Why can´t you guys just put the bloody converting program in Screenflow and save us the pain and trouble? At least you could have given me an alert about the .MOV files I´ve put in there. I´ve now downloaded 3 converters and none of them does the job. I don´t want to pay another 50 bucks (500 Sek, yes I live in Sweden) to do what Screenflow should have done in the first place.
This sucks!!
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April 14th, 2012 at: 4:11 am
I’m planning to use Canon 600D to shoot some video for my educational combocasting (special thanks for your combocasting course). This DSLR generates H.264 encoded video. So could you suggest then best practices for importing such video into ScreenFlow? What do you think of picture quality degradation while converting video back and forth?
Thank you!
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Lynn Elliott Reply:
April 23rd, 2012 at 4:34 pm
HI Egor,
Take a look at this article… It has some tips for converting your H.264 footage to an editable format: http://blog.vincentlaforet.com/2009/11/02/converting-that-h264-footage/
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April 25th, 2012 at: 3:14 am
Resonating on @Veit’s suggestion, why not also offer to convert ingested video into an editable format? There is no other reason to ingest video clips into ScreenFlow, correct? ScreenFlow would need to know what CODECs are available and then present a pop-up menu to choose the CODEC from.
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Lynn Elliott Reply:
April 25th, 2012 at 7:48 am
Yes, great idea Frank. Thanks.
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May 1st, 2012 at: 7:13 am
I’d also suggest Apple Intermediate Codec. While it’s not quite as good as Apple Pro Res, it comes with iMovie and therefore it’s on every Mac these days
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Conny Reply:
July 5th, 2012 at 7:08 am
Ok, but this is all Greek to me. I´ve tried to mix down the MOV-files from iMovie and ended up with m4v? But that´s mpeg? Am I right? And mpg can´t be used with Sceenflow… I´m about to give up…
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Lynn Elliott Reply:
July 5th, 2012 at 9:14 am
HI Conny,
I’m sorry you’re having so much trouble. Try exporting all keyframes. (from imovie, you can do this by selecting Share > Export from QuickTime then click Options and select Compression Type either h.264 or mpeg-4 video, and Key Frames = “All”. This will export every frame as a keyframe. The result will be a very large movie file, but each frame will contain all that frame’s information, so the editing software can edit without a lot of forward and backward processing.
Alternatively, (depending on how large your movie is), you can experiment by decreasing your frame rate. So change the Key Frames to “every 5 frames” or less. This will also make for a large file, but not as large as if Key Frames were every frame. You can also experiment with compression quality for each of these scenarios, to try to reduce the overall file size.
YOu might find that the difference between “Medium” quality and “High” quality is virtually undetectable, but it may reduce your file size tremendously.
If you’re still having problems, I recommend you contact our support department, and they might be able to diagnose what’s going on in more detail: http://bit.ly/AkwDac
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May 11th, 2012 at: 10:28 am
Using the ProRes format has completely removed any lag issues I’ve had. I can now import large .mov files without issue. Thanks for reminding me about this Lynn.
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Lynn Elliott Reply:
May 11th, 2012 at 11:47 am
Great to hear!
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May 22nd, 2012 at: 9:58 am
I just have to add that not using ProRes format in my projects, has proven to be the MAJOR issue when dealing with crashes while working on large .mov files that I imported into a project. This is probably worth an ALERT email to your subscriber base, because I still hear from others via social media about crashing.
I don’t know much about formats, but it seems the ProRes is only Apple, which for some of us can cause some grief because we record demos on our PC, then import into screenflow as a .mov. I looked for something, (including your handbrake suggestion) that would convert the file to ProRes, and I have yet to find software that does that. I even use iSkySoft which doesn’t mention ProRes either.
Given how valuable this conversion is to a smooth workflow, I think that Telestream should come up with a built in solution that offers users an easy way to convert all imported files into ProRes. Just my thoughts.
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Fernoperator Reply:
June 14th, 2012 at 1:50 pm
Forget apple pro res and try converting to h264 or photoJpeg movie files. These are the most universal formats around. Most people get the Apple Pro Res codec from installing FCP which everyone does not have anymore since the new FCP10 system is amature. DNxHD36 is another good codec that works well in Avid. Stream Clip is a good converter program. Plus it’s free!!
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August 13th, 2012 at: 7:27 pm
I just purchased a new IMac 2.GHz Intel Core i5 Quad-Core, 4GB ram
to replace my dead PPC G5,Tiger & FCP 6. I am considering a Sony HDR AX 2000 for my next camcorder but have some concerns with importing AVCHD and possible sluggish workflow in Final Cut Pro X which I have not purchased yet, any help, advise or recommendations would be greatly appreciated thanks.
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Lynn Elliott Reply:
August 14th, 2012 at 7:44 am
I don’t have any personal experience with AVCHD and Final Cut Pro X. My understanding is that it was possible to ingest it, and FCP would convert it to ProRes for editing. That tells me that AVCHD is not an editing format, so if you want to import it into ScreenFlow, you might do well to transcode it first to Apple Intermediate Codec or uncompressed. Here’s an article I mentioned above that might be of some value: http://blog.vincentlaforet.com/2009/11/02/converting-that-h264-footage/.
If anyone has any specific experience with this, please share.
Lynn
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December 21st, 2012 at: 4:53 pm
[...] cause any unexpected hiccups. Finally, and most importantly, we transcode our video content into a format that’s much more like the old DV standard, with individual frames stored as separate pictures. This all makes iDVD’s job of DVD [...]
December 22nd, 2012 at: 8:27 am
We record video interviews using skype and call recorder and then edit with screenflow. This works fine if there are not too many edits to do. The problem occurs when ther ar maybe a dozen edits in a 40 minute show. During exporting the screen can go blank except for the text box. Please advise.
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Lynn Elliott Reply:
December 24th, 2012 at 3:22 pm
HI Beryl,
For such problems, please contact our support department, and we can look into it further. http://bit.ly/AkwDac
Thank you,
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