XVID HD : quality problem when 60 fps

phkoech · Post by **phkoech** » Thu Jan 03, 2008 1:47 am

Hello,

I have made some test on converting 59.94 FPS 1080i video into XVID (see viewtopic.php?t=3064).

When my output format is 29.97 FPS + 8000 kbps, quality is quite nice, but when my output format is 59.94 FPS + 15000 kbps, quality is bad (like if bitrate is too low).
So my conclusion is that it is not possible to use mediacoder + XVID codec to encode into 59.94 FPS 1080i because maximum bitrate allowed by media coder is to slow (16 000 kbps).

Is this bitrate limitation due to mediacoder or XVID codec ?
Is there a solution to encode XVID 59.94 FPS 1080i ?
If not, is it a good solution to get FPS down from 59.94 to 29.97, so that to have a better quality ?

SirAuron · Post by **SirAuron** » Thu Jan 03, 2008 5:15 am

Having more than 29.97 FPS does not make the movie any smoother or improves the quality. The human eye is only able to see at 24-25 FPS. I think the reason why some hidef movies have higher frame rates is for features like slowmotion or similar (at least I can't imagine anything else).

I suggest you use either 29.97 or 23.97 to get relatively small filesizes at a good quality.

phkoech · Post by **phkoech** » Thu Jan 03, 2008 9:01 am

OK. Thanks for your advice

I will forget 59.94 FPS and convert my video into 29.97 FPS.

phkoech · Post by **phkoech** » Thu Jan 03, 2008 6:17 pm

Humm, one more question about 60 FPS video :
Is it possible to convert 1080i 60FPS video into 1080p 30 FPS video (using mediacoder>picture>effect>de-interlace filter) ?
Is there a significant gap of quality (on a 1080p TV of course) ?

B!ink · Post by **B!ink** » Thu Jan 03, 2008 7:42 pm

phkoech wrote:Is it possible to convert 1080i 60FPS video into 1080p 30 FPS video (using mediacoder>picture>effect>de-interlace filter) ?
Is there a significant gap of quality (on a 1080p TV of course) ?

It's possible. Try it out and see for yourself. If you plan on using de-interlace filter, start off with linear blend. Just out of curiosity phkoech, what brand HDTV do you have and how much did it cost you? 1080p HDTV are quite expensive.

phkoech · Post by **phkoech** » Fri Jan 04, 2008 12:18 am

So I will try encoding 1080p and make a report on this topic. in a few days.
My TVHD is Sharp 46XD1E. It is not so expensive in France : about 1500€ (2200 $). But it was twice this price one year ago !

V@no · Post by **V@no** » Mon Jan 07, 2008 8:49 am

SirAuron wrote:Having more than 29.97 FPS does not make the movie any smoother or improves the quality. The human eye is only able to see at 24-25 FPS.

This only correct if the source is not more then 29.97FPS. otherwise you will see the difference between 30fps and 60fps

Post by **stanley** » Tue Jan 08, 2008 3:45 am

Could you upload a 59.94fps clip to ftp://mediacoder.3322.org?

guest · Post by **guest** » Tue Jan 08, 2008 7:27 am

59.94 FPS is smooth if source is pure interlaced. (movie is progressive). everybody can detect this smoothness.

as I know, If you want 59.94 fps with mediacoder

1. Go to File - Settings - Overall - Decoding options - Override framerate
2. Enter 59.94 and apply (can't apply exact fps 60000/1001)
3. Go to Picture Tab - framerate - write down 59.94 (manually, or add fps preset first and select)
4. Select Effects - De-interlace - yadif mode 1 (or 3)

in advanced mode check command line if there is -fps 59.94 -ofps 59.94 (or 60000/1001)

5. encode

it is very inconvenience. especially specifing frame rate.
please make it more easy

phkoech · Post by **phkoech** » Mon Jan 14, 2008 6:31 pm

stanley wrote:Could you upload a 59.94fps clip to ftp://mediacoder.3322.org?

Sorry for the delay, I was out for the week.
I have uploaded my 1080i 59.94 FPS video file on the server (name = "sanyo 1080 complete.mp4").
I would like to convert it into a more standard video format that I can read with standard player (WMP, nero, powerdvd...), so I have tried h.264 29.97 FPS and xvid, but I'm not sure this is the best solution.
If you succeed in transforming it into readable file, please let me know the mediacoder settings