-
Quick Time Pro H.264 video problem
I am using a blackmagic decklink video card to capture uncompressed video with Media Express. I then use Quick Time Pro to convert to .mov files (using H.264 codec). After doing this my video has some strange “banding” in it. Any time there is motion on the screen or if the camera moves, there are horizontal bands on the screen, like it isn’t compressed correctly. It looks like each frame, some parts of the screen continue normally but other parts are “stuck” in the previous frames.
Is this caused by my Quick Time conversion from uncompressed to .mov using H.264? If so, how might I avoid it? Would Motion JPEG be a better codec to use?
-
6 Replies
-
Hi Jeff,
An h.264 conversion, if done properly, should look exactly the same as your source media. If you could post a sample clip of your media or at least some before and after screenshots, it would be easier to diagnose the problem.
Using h.264 or Motion JPEG is a big and varied decision, one which solely depends on the intended output of your media. Are your creating this for web distribution, a specific playback device, or for editing with other software. Creating an h.264 version should be the very last step in your workflow (if you’re creating a distribution version).
Troublshooting questions:
1. Are you capturing HD or SD?
2. Does your captured media have these same banding issues?
3. Are there an frame rate conversions happening?
4. What is your captured frame rate?
5. What settings are you using to create your h.264?—
Let us know when you’ve solved your issue. -
Please post a screen grab of the problem you are seeing, just so we know exactly what we are dealing with.
__________________________________________________________________
Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
The H.264 version is the last format in my workflow. It gets recorded to tape from there.
To answer your questions…
1. Are you capturing HD or SD?
SD only2. Does your captured media have these same banding issues?
The original betacam SP tapes that are used do not have this problem3. Are there an frame rate conversions happening?
To my knowledge, the offices that use this go with 29.97 for the uncompressed file and also 29.97 for the Quick Time conversion to H.2644. What is your captured frame rate?
29.97 frames per second, NTSC5. What settings are you using to create your h.264?
I believe it is simply 29.97 FPS and on the “Better” or “Best” option for quality.The uncompressed file is an AVI file and the H.264 codec conversion ends up making it Quick Time. Would this affect it? Perhaps Quick Time Pro does not handle AVI files very well?
-
Hi Daniel:
Unfortunately it is difficult to show the problem on a screen grab because it only occurs during motion on the screen. Also, it only shows up on actual television monitors, not on a computer screen. I will continue to look into it… thanks for offering to help though.
-
Ok, sounds like there’s a problem in the transcode, probably with the way the fields are being processed. My best advise to you is NOT to use Quicktime Pro to do the transcoding. Do you have access to any other transocding software? compressor, episode or squeeze for example?
What OS do you use?
__________________________________________________________________
Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004 -
Hi Daniel:
The OS is Windows XP
Reply to this Discussion! Login or Sign Up