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HD PVR 2 Pixelation issue after rendering
Okay, I’ve had this issue for quite some time and could really use the help. Whenever I preview my Hd pvr clip in Arcsoft Showbiz it looks absolutely fine, no issues. But then, I put it into Sony Vegas, edit, render it and the video comes out pretty bad. My clip is mp4, and after I render it, I get these weird pixelated boxes on the sides, sometimes it can be really bad. I’ve tried increasing bit rate, disabling resample, 2 pass variable bit rate, everything. What’s the problem? I would appreciate any feedback 🙂
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7 Replies
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What render template did you start with an how high did you make the bit-rate? Pixelation is usually caused by not having enough bits so you are doing the correct things. Maybe you didn’t go far enough?
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Thanks for the response! I use Main Concept AVC/AAC OR MP4. But I’ve tried using 14,000,000 bps, which is max HD pvr records. I found that I get the least pixelation when I record 10,000,000 bps in Arcsoft, and have a constant bit rate of 10,000,000 bps in Sony Vegas. With what I rendered today, the clips haven’t turned out bad using 10,000,000 as a bit rate. I haven’t seen any pixelation. But I’m still not sure what the problem was..
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The problem is with the content. Some scenes have too much detail for it all to be represented properly and when you run out of bits to represent the scene you get blockiness. I’m glad you found something that works.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Thanks! I’m just still curious why other people don’t have this problem?
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[Tristan Burns] “I’m just still curious why other people don’t have this problem?”
They do… lol… they come here all the time with the same question that you just had and we tell them to (1) Increase your bit-rate and (2) use Two-pass encoding.
You can also use a slight Gaussian Blur to the whole project and desaturate it slightly to make it easier for the encoder to do it’s work. Computer graphics are the hardest thing to encode into a video stream that uses interframe compression at low bit-rates like AVC/h.264.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
Okay thanks for the help! But also.. If I do variable bit rate (2 pass) what should the maximum & average bit rate be?
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[Tristan Burns] ” If I do variable bit rate (2 pass) what should the maximum & average bit rate be?”
You want the maximum to the enough to handle the most demanding scene in your video. So increase the maximum until you don’t see any more blockiness (maybe 14Mbps?). The average is what controls the file size so keep the average at 10Mbps if that’s working for you now, or you could lower it to 8Mbps and perhaps get a smaller file with the same quality because the maximum will take care of the difficult parts.
What two-pass does is make an initial pass to see how many bits it needs to encode each frame. Once it knows that, it does the second pass to actually encode it. This allows it to steal bits from frames that don’t need it and give them to the frames that do while still maintaining the average that you have set for the overall video. It takes twice as long but yields the highest quality with the smallest file size.
~jr
http://www.johnrofrano.com
http://www.vasst.com
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