Converting HD Videos without significant quality loss

[kurian]

Hello friends,

I have got many HD films(H.264 & AAC) ranging from 3-6 GB but they are consuming all my disk space. I have seen compressed HD videos with small sizes and unnoticable quality loss .so i am assuming that i can convert my films without much quality loss.i want them to be re-encoded to 2 GB (1.5 GB video and .5 GB audio).searched on google about this but seems pretty much confusing since there are many software & encoding methods to do this .so i request the video experts to suggest which s\w ,encoding method should i use to yield the output which can save my time and quality.sorry if i have posted in the wrong thread.

Thanks in advance

[Baldrick]

Use a x264 frontend like handbrake. But encoding HD will take a LOT of time....I would buy more HDD instead.

[kurian]

Thanks baldrick. i also want to ask another question.hope u don't mind .i learned that there are many other tools which do x264 encoding like ripbot264,xvid4psp,alltoavi,supermeguiand many other.so which is the best s\w for x264 encoding considering quality and time consumed.

[davexnet]

I don't think there is any difference in the encoding time, since they're all x264.
The main differences seem to be which options are exposed in the GUI, but I doubt even that is not
that big of a deal - unless you're an x264 expert, in which case you'll probably be using the command line.

Try the popular ones and see what you likle. Handbrake, Staxrip, xvid4psp, etc,etc...

[guns1inger]

Unless your source is encoded with a very generous bitrate, there is no way you can reduce them by 65% and not take a quality hit.

[kurian]

Thanks guns1inger for Ur opinion.here is a sample of HD video i want to re-encode.can you explain 'generous bitrate' for this file(video stream alone 3 GB).so that i can encode them to 65% of source file without affecting quality as you said.

[leghorn]

Video bitrate is ~3200 kbps at 1280x544 px.I dont have much experience in downsizing HD videos, but I think you could down to ~2000 kbps. If you want to go even lower you should also consider resizing.

[zammil]

thanks leghorn for your concern.so i want my 3 GB video to convert to 1.5 GB so how many kbps should i use or should i prefer two pass encoding.

[jagabo]

thanks leghorn for your concern.so i want my 3 GB video to convert to 1.5 GB so how many kbps should i use

Half the bitrate of your source. Because:

file size = bitrate * running time

So for a given running time the bitrate determines the file size. (The sum of the audio and video bitrates, plus a little overhead for the container.)

Nobody will be able to tell what the resulting quality will be because every video requires a different bitrate to maintain quality. A slideshow with no transitions can be encoded with very low bitrates and look fine. A video with a lot of noise and action shots will require lots of bitrate.

or should i prefer two pass encoding.

You should always use two pass encoding if you want the best quality at a particular file size.

[kurian]

Thanks to everyone who has taken time to reply to my thread.I have also got the optimum settings for x264 conversion from the following guides.hope it will be helpful to others.


http://www.videoforums.co.uk/submit-your-own-guides-reviews/23573-h-264-encoding-x264-...round-far.html

http://mattgadient.com/2009/09/12/the-best-h-264-x264-settings-for-handbrake/

[pectin232]

Yes I have seen mp4s on some which are even around less than 700-900MB and quality for those mp4s are just incredible. I have reencode avatar extended gtom blu ray to mp4 but seems not to get below the 2gb mark using xmedia recode and it is terribly time consuming. Any other tools besides those mention and add subtitles as well? XVid4PSP does not work with Windows 7 64 bit somehow on mine anyway.