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Monday, July 26, 2010

2 pass encoding vs. constant quality encoding

2010.7.28 15.00
and why frame grabs are not always reliable when you want to compare quality.

I tried to grab exactly the same frame every time what proofed to be futile, so this is as close as its get.
Also I made lossless crops from the 1280x720 screen shot  in 640 x 640 pixel that you do not need to click on the picture to see the full size. This size is the maximum Blogger can display in the posting. They are re-compressed by Blogger, but I compared the posting images with my originals and they are comparable.
All grabs are done in GOM player.
Just hit F11 now to go full screen in your browser and it is very easy to just scroll up and down to fast compare the results. When you are finished hit F11 again and your browser is back to normal.

RF:25 190 MB  1100 Kbps

Sunday, July 25, 2010

Encoding cartoons in AVCHD

2010.7.25 1.38
How far can we compress a 21 min cartoon in 720p HD and keep a good quality.
Would you believe me that you can reach a file size from 75 MB and it still looks acceptable?

If you do not understand the RF:xx, read Shrink your video files first.

 RF:20, High Profile, 23.5 Mb first minute
Video: 3043 Kbps Audio: Dolby Pro Logic II 160 Kbps
this high encoding results in a ca 500+ MB large file



Monday, July 19, 2010

Shrink your video files

2010-7-19 15.11
Why would you want to re-compress you video files?
Well, I don´t know about you, but with the quality the Sony HX5 gives me in videos, I find myself using the video function more and more. And that shows on my disk. Where before a DVD was enough to archive several years of picture memories including some clips, now a DVD would be filled in a matter of weeks.
So I need a way of keeping the videos I want but if I could get them smaller without loss of visible quality that would be perfect.
After spending several days work to try all kinds of programs and fiddle with the settings to get exactly the results the way I wanted it it is time to share that information with you. In one sentence: You can save 50 to 75% of space and keep a good quality.
 
If you have lots of movement over most of the screen, then re-compression might not save you much. This 3 min clip "Fiesta del Carmen Gran Canaria 2010 - Sony HX5.MP4" in the original is 150 Mb re-compressed with RF:25 (see below) brought the file down to 132 Mb. In a case like this you already got the best compression / quality ratio in the original file.


If you have a mostly static scene like on this 32 second clip a small grasshopper drinking, you can archive a compression from the original 24 Mb to 3.3 Mb at setting RF:25 what is quite a lot for nearly the same quality.


Now, how is it possible to compress one file so much and another nearly not at all?
Coming from over 10 years of getting video clips to the computer starting with VHS-C, the Snappy to grab images out of the videos and the DAZZLE with a parallel port to encode to REAL Media with QVGA in the last Millenium we have come a long way and the two pass encoding in AVI is so yesterday.

Thursday, July 8, 2010

AVCHD - encoding the new way

2010-7-9
Video Compression - Size vs. Quality
All the tests are done with Handbrake.
For more info see the Shrink you video files post.
Let us see how we can get the smallest file size with the quality you want.

I did some testing with several blue ray disks.
RF 28 did show some slight problems with compression artifacts in dark areas RF 25 has less.

AVI - encoding the old way

My goal was to find an easy to use free software what converts the Canon SX1 monster files into a good quality format what works with low power hardware.
That is a 1,6 MHz notebook with a Centrino Duo 2 GB and a Nvidia GO 7300 XP SP2 and a 1,6 MHz notebook with an AMD Turion X2 1 GB with an ATI XPress 1100  XP SP2

I liked best so far SUPER it is free, simple and powerful.
Get it here.

WD TV - if your computer stutters with X264

So your puny computer has problems playing the clips from your camera.
Welcome to the club.

On my search for an affordable solution to play full HD files on the big screen I found an interesting gadget.
After learning the hard way that a media player with or without hard disk and a HDMI port does not necessary also plays  HD videos I needed to do some research on that topic.
In my case the media player enclosure did not even wanted to touch SVGA (800x600) or anything with a higher resolution. No way to ask for a down sampling or so. Just DVD resolution is the most these units want to play.