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Video is Pulsing Every 2 Seconds
So here’s my dilemma. I was recently hired as a videographer and wanted to test out the Sony Z5U camera which I had access to. I shot some footage the other day to become more familiar with the equipment, and captured it in 1080i and in a scan mode of 24A. I then edited imported (via Sony Hard Drive – no tape exporting was involved), edited and exported the footage all in Adobe Premiere CS3. I’ve been out of the video production scene for some time now, so I have a few questions. Take a look at my video first, and then take a stab at my questions: https://www.youtube.com/watch?v=RVx7p7Wj9ss
1. Why is my video pulsing? It’s not very noticeable, but at 0:20-0:30, you can still the background pixilate in intervals.
2. I recorded in 24A, but should I have recorded in 24p or 24i?
3. If I record in 24A (or another format), which frame rate (or other settings) should I set the export file to? 23.976, 24, 29.970, 30, 69?
4. Am I missing anything here?Thanks in advance for the help. The experts on creative cow are by far the best out of any site out there. Let meknow if I can provide any additional information to be of further help.
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4 Replies
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Welcome to compression and keyframing.
Keyframes are actual “full” frame where the entire frame information is stored. So if you set your export to keyframe every 48 frames (2 seconds at 24p), everything in between will only contains changed pixels (averaged with some complex motion blurring). That means that at very low compressions, you will see what seems like a jump once you get to the actual keyframe. The solution would be to lower the keyframe interval and raise the bitrate. Note that the more static the video, the more you will notice that change, but it’s there in most videos if you pay close attention, even Hollywood DVDs.
For Youtube, export at the highest bitrate possible. You are allowed 2 Gb for 10 minutes so don’t be too worried about the bit rate. Try 3-4 Mb/s H.264
Vince Becquiot
Kaptis Studios
San Francisco – Bay Area -
Thanks for your explanation. It helps to wrap my brain around the whole frame rate thing.
I was doing some trial and error with your suggestions and found that using the H.264 Format was causing some of the problem. I tried exporting as a QuickTime format with a H.264 codec. The video seemed much smoother once I did this. The only problem now is that I don’t get as many vibrant colors… looks like I need to do a little more trial and error..
Thanks again for the help.
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Martin,
Washed out colors are a common issue with H.264
The best solution I can recommend is to get a copy of Quicktime Pro, export from Premiere as Quicktime Animation at 100 %, import into Quicktime Pro and do the export from there. A better compressor these days is Sorenson Squeeze if you can afford it.
There is another workaround here, although that could create jitter.
Vince Becquiot
Kaptis Studios
San Francisco – Bay Area -
Fast forward 4 years…. Go to “Sequence Settings” and change Editing Mode to “Custom”. I think the default is some odd camera brand – ARRI Cinema??. I called Adobe tech support. They immediately went right to that and it cleared it up instantly. Trust me on this…. He also suggested when exporting to use any one of the “HD” group of settings. Not sure if that matters, since it also works well using the “Vimeo” presets.
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