![]() ![]() ![]() So for encoding speed, it's more a factor of resulting file size than actual vid quality? ie: medium- larger file, slow- smaller file, but relatively similar quality? I'll let it finish out, since I waited this long already, but may just go back to 1280x720 as the one I did earlier (on very slow) came out quite good and was ~780MB, I guess it's quite a jump to 1080p from there. I haven't done much crf encoding with this, or any other app, because I wanted control over the bitrate and/or filesize, but I may look into that, will make a clip from source, and do it that way, I thought I had a handle on it so went for full encode, but prob the one i'm doing now is fudged as well (4200kbps, on slow), blu-ray source too, so it's bitrate is 19,700kbps! for vid. Alternatively, I could also use a higher crf (like 23 or so) which will result in a loss of quality, but it shouldn't be too bad and will signifcantly reduce the file size further. Had I used slower or even very slow, the file size/bitrate would have been further reduced without quality loss. With crf=20 and the slow preset, while not resizing/cropping anything, I ended up with a file almost half as small (132MB vs 249MB) which used a bitrate of 5100kbit/sec and looks transparent to me. The encoding time was also around the same (took 10 minutes longer for a 1hour 50 minutes movie).Įdit: I did a 1080p test myself now, took the Avatar 1080p trailer which has 9720kbit/sec. To emphasisze how this all is a good idea: I recently backuped a DVD and first did a normal 2-pass mode encode (preset: medium) with a targeted filesize of ~1,2gb, then i used constant quality mode with crf 19 and slow preset, and the final filesize was something around 800mb with basically identical, if not even slightly better quality than the 400MB bigger 2-pass encode (it's a bit hard to tell which is better because the DVD source has some artifacts aswell). General rule: the more slow or bright scenes a movie has, the bigger the final size will be. Be aware however that every movie behaves a little different with constant quality, so two different 90 minutes movies can potentially have a huge size difference with exactly the same settings. ![]() Play around with this (I recommend using a movie trailer in 1080p for testing purposes) until you find a good mix between quality, file size and encoding time. In crf mode, this will not or only minimally affect quality, while greatly increasing the filesize since the encoder compensates the lower encoding complexity with MOAR bitrate. However you could also set the preset to fast or faster. If it's small enough for you so that you are willing to let it get bigger you can a) either decrease the crf further or b) increase the output resolution, both will result in a bigger filesize with the same settings (you won't probably be able to get a 1080p file 45mins under 2gb though even with the slowest preset, but maybe around 2,5-3gb, depends on the source). First try with Medium preset then and look how big the file gets (you cannot predict file size with constant quality). First set your rate factor to something between 20 (good quality) and 18 (very good quality) (the lower the number the better the quality, but everything below 17 becomes neglectible). You could also try to go for constant rate factor (constant quality). ![]()
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