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-   -   FFMPEG video converting, VERY pixelated (http://www.linuxquestions.org/questions/linux-newbie-8/ffmpeg-video-converting-very-pixelated-857531/)

Helstedxd 01-20-2011 08:43 AM

FFMPEG video converting, VERY pixelated
 
Hi Everybody

I am trying to make my server convert my videos to FLV in a descent quality but i get very bad quality from the converting i have tried:

Here i tried to convert WINDOWS 7 standard movie Wildlife.wmv to FLV with its original specs

Code:

ffmpeg -i /var/videos/Wildlife.wmv -s 1280x720 -ar 44100 -r 29 -ac 2 /var/flv/Wildlife.flv
and here is the result:
http://www.myupload.dk/showfile/74484251994.flv/

//Helstedxd

N.B. Here is the source if you dont got it:
http://www.myupload.dk/showfile/744843be41e.wmv/

H_TeXMeX_H 01-20-2011 12:44 PM

If you want better quality use a '-b' bitrate option or '-qscale' option.

For example '-b 5000k' OR '-qscale 7', the lower the qscale the better the quality, the larger the file.

Just so you know, at that resolution, for good quality flv, you would need around 10000 kbps, which is a lot.

Possibilities:
Code:

Video:
    1)    -b <bitrate> (bps) [200k]
    2)    -sameq        =variable bitrate same quality
    3) -qscale <q> =fixed quantizer q = 1 (best) - 31 (worst)
        -maxrate <bitrate> (bps)
        -minrate <bitrate> (bps)

I much prefer using qscale (VBR) over bitrate, because it results in better overall quality, and more consistent quality across files (same resolution, same framerate, same codecs).

I would also use the '-async' option to prevent A/V desync, as well as proper FPS:

Code:

ffmpeg -i Wildlife.wmv -s 1280x720 -ar 44100 -async 44100 -r 29.970 -ac 2 -qscale 5 out2.flv

Helstedxd 01-20-2011 01:43 PM

Thanks H_TeXMeX_H it worked :D

H_TeXMeX_H 01-20-2011 01:45 PM

Yeah, but test it, make sure it works with reasonable CPU usage and flash player. It may not handle large bitrates well.

Helstedxd 01-20-2011 01:49 PM

i did and it worked perfectly ;)


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