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video on YouTube - shaky lines

   
5:29 pm on Apr 16, 2010 (gmt 0)

WebmasterWorld Senior Member 5+ Year Member



After I posted a video on YouTube, I found outer lines of moving objects (people in particular) being kind of shaky or like a snake.

The videos were converted from DVD format to MPEG version 2 as:

720x480
Data rate: 2600kbps
Total bitrate: 2728kbps
Frame rate: 29 frames/second

Would this be OK when about quality?

Thanks
3:02 am on Apr 17, 2010 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member



You're probably seeing the result of not deinterlacing your video and combination of something exacerbating it.

Standard video shot on regular camcorders is interlaced, each frame is actually two frames. Each line of resoltion alternates between the two frames. If you view a frame in your editor where fast movement is occurring you'll see comb lines. This is standard on a regular TV and the player takes care of it for progressive TV's. For playback on a computer monitor the software will deinterlace it on the fly.

Leave it interlaced EXCEPT when you're going to use it for something like youtube. Most editors or encoders will an option to deintelace. Keep in mind deinterlacing is a destructive process hence the reason you don't want to do it it unless necessary, basically half the resolution gets thrown out.

FYI DVD is MPEG2 witha few extras, assuming it is not a commercial DVD you can rip them fast with something like Vob2MPG

Also that bitrate is too small for that resolution, once you get into the 4000 range with 720X480 it goes downhill fast.
5:03 am on Apr 17, 2010 (gmt 0)

WebmasterWorld Senior Member 5+ Year Member



That sounds good - thanks. I'll go back and play with it again.

comb lines


Tyne comb lines were what I saw on the PC at some moments.

I saw the same video put onto youtube by another person, and it was perfect.

I used a free Any Video Converter.
2:30 am on May 22, 2010 (gmt 0)

WebmasterWorld Senior Member 5+ Year Member



I got a chance to play with this again today and it did not work. It's either with those comb outlines, or it's kind of "dirty" (like very low resolution.

The VOB files are fine. Both VOB and output files (after conversion) look fine on PC.

I even tried uploading VOB directly, and it turned "dirty".

VOB properties are:

720x480
Data rate: 10000kbps
Total bitrate: 10256kbps
Frame rate: 29 frames/second

The file size is 154 MB, and I was converting it to outputs anywhere from 64 to 185 MB.

Questions:

- If I was able to upload VOB directly, why convert?
- Why direct VOB upload turned into very low quality?

Many thanks.
6:57 pm on May 22, 2010 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member



If you play this DVD from a standalone DVD player on a SD TV check to see if you notice any ghosting during fast motion. It's kind of hard to explain, similar to if you used that stupid pointer trails feature on Windows. If there is not a lot of action or you don't know what you are looking for it may be hard to detect but if you see ghosting or trailing it was encoded with the wrong field order.


The VOB files are fine. Both VOB and output files (after conversion) look fine on PC.


Software players deinterlace on the fly, you'd see the comb lines if they didn't.

- If I was able to upload VOB directly, why convert?


For a variety of reasons, VOB is MPEG2 which is a proprietary codec for starters. MPEG2 is about 4 or 5 times the bitrate than what would b required for a newer codec. Lastly and most important Flash doesn't support playback of MPEG2.

- Why direct VOB upload turned into very low quality?


If you're still seeing comb lines after directly uploading the source video my guess is you have a problem with the source as I outlined above.

4:39 am on May 23, 2010 (gmt 0)

WebmasterWorld Senior Member 5+ Year Member



Thanks.

I switched from the free converter to Nero that I already had installed.

I played a bit and ended up with exporting the VOB into Nero Digital AVC at 9800 kbit/s, frame rate 30, interlaced. That gave a good result.

Interesting fact was that with the free converter, no matter to what I set the bit rate, the export version was around 1000 only.

I wish I know more about what was behind, but really don't have time for it.

For now, I'll use that Nero thing.
4:29 am on May 24, 2010 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member



Probably should have noted a VOB file is just a MPEG2 with some extra information for DVD, ideally you just want to rip the file from the disc without any conversion. You can use Vob2mpg for that. It will strip any extra data related to the DVD and output a MPEG2 file. There's no conversion which is what you want, this is really fast withno loss in quality. Any conversion of video will result in quality loss so it should be avoided during intermediate processing. You should only do one conversion.

Source >>>> Destination Format
5:39 pm on May 24, 2010 (gmt 0)

WebmasterWorld Senior Member 5+ Year Member



What really happens when I upload a file to YouTube? What kind of conversion?

I ask this because I was able to upload VOB directly and the result was very poor.
 

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