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Old 25th July 2019, 10:35   #1598  |  Link
donpoku
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Join Date: Jun 2019
Posts: 5
Quote:
Originally Posted by r0lZ View Post
Sorry again, for whatever reason, the forum do not send me the notifications for the new posts any more, hence my late replies.
When you re-encode a video file, there is always a loss in quality, except if you use specifically the lossless options. And re-encoding losslessly doesn't make much sense, as usually, the size of the final MKV file is greater than the original M2TS file ! So, the question is : what amount of loss of quality can I accept ? I can't reply for you, but usually, I consider that it's mainly a false problem. Of course, if you compress extremely, the quality loss will also be extreme, and therefore much visible, but most peoples cannot see the difference with the original BD (without using special tools) when the default option (CRF 23) is used. The decrease of the file size is NOT really an evidence of a visible quality loss, and it depends largely of the images of the original movie. Trust your eyes, and do not imagine that you can see a difference because you think that a small size means bad quality.

That being said, you can easily modify the quality (and the size) of the encoding. As noted by tebasuna51, the CRF mode is recommended, because it adapts itself so that you will always obtain more or less the same quality, but the file size may vary, especially for old films with much noise. The CRF parameter can be used to increase the quality and the file size. The default value for x264 (CRF 23) gives good results for a very small file size, but you can decrease it to, say, 20 or even 15 to obtain a much better quality, but take in mind that the file size of the video stream can be doubled when you decrease the CRF value by approximately 3.

BTW, to encode in lossless mode, use CRF 0, but buy a big hard disc, as you will obtain a huge file size !
Thank you for the response I'll give it a try. Bless.
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