1080p -> 720p encode question, file size

[Celeras]

Was shrinking down a 1080p BD rip for my Nexus as theres no reason to use that size on a 720p device. I've got encoding/compressing raws for the web down to a fine art, but not so much for mobile starting with somebody elses source. I used Format Factory and just chopped the original down with the 720p preset, H264 @ 2400 KB/s and kept the original FPS/container(mp4).

It looks mint but I was a little disappointed with the file size, original was 2.75gb and it only dropped down to 2.06gb. I guess I expected a bigger drop since I was going to 44% of the pixels(1080p>720p). Does that sound right, or is my thought process just mistaken.

[Tyche]

Just out of curiosity, why not just download the 720 matrovsky and pull the file straight from the container? I know 720p files seems to be a lot smaller than 1080s when packed in mkv containers.

[Celeras]

I could have I guess, but didn't want to have to seed my ratio back up. This was more of a knowledge question anyways. Would it have been better to just do the same thing I did except as an mkv? Cos I didnt think that made a difference.

[edit] and I checked, and theres a 720p version up on what I use but its only 600mb.. so you know that shits gonna suck anyway lol.

[SephYuyX]

720p MKV isnt really that bad.

If youre familiar with YIFY, he does BluRay to 720p quite well while keeping the size under 800MB and usually around 650MB.
One of the things he does to reduce size is taking away some of the audio quality, but just in the effect of having to need to turn the sound up higher when youre listening to it. The video is usually pretty good.

[Deadgye]

[edit] and I checked, and theres a 720p version up on what I use but its only 600mb.. so you know that shits gonna suck anyway lol.

What length and how much action are we talking about? Nowadays if it's 10bit you should be anywhere from 120-400mb per file for ~25 minute 720 episode.

If it's a movie.. yeah I probably wouldn't download a 600mb one either.

[DAKPluto]

2.75 seems small for a 1080p

[Celeras]

Definitely is, my Dark Knight copy is over 11GB. Something else was done to it I'm sure and I don't know/can't tell what, but it looks flawless. Anyway its an hour and 52 minutes, movie.

[hey]

Eh, depends how it's encoded. 2-3 gb, and 10 gb+ are both common for 1.5-2 hour 1080p movies. Personally i don't really see much difference from the slightly improved video, and flac audio, but it's not like it takes long to dl 10 gb, so why not? If you're trying to conserve space and/or bandwidth though, 2-3 gb for a movie is barely even going to be noticably different from a 10 gb+ encode.

[Celeras]

Well I have 32GB on my Nexus. So I'm not really worried about the 0.5GB I could be saving on this one video, but if there's a way to do so it would be worth knowing as that can add up. Like I said in the OP I just expected a bigger drop going from 1080->720p, but if the numbers sound right to people I guess it is what it is.

[DAKPluto]

For my HTPC I do mostly 720p since it honestly still looks amazing, and not too noticeable difference from 1080p. And most of my 720p average 2-3.8gb depending on quality, audio, etc. So it seems right. Just sounds to me like your original 1080p was ripped at a lower quality, hence the reason you saw little drop.

[Obiron]

Sorry to hijack the thread, but I have similar questions. I've recently finished ripping all of my DVDs and Blurays for my HTPC, but I haven't re-encoded any of them. For the most part, I'm sitting on ~5GB mkv files for my DVDs, and ~30GB m2ts files for my blurays. Space isn't an issue yet, but I've been starting to look at re-encoding before it does become an issue. Can I just use Handbrake to reduce their size, or are there better alternatives recommended? DVD is already fairly low quality by today's standards, but I wouldn't want to make it any worse, just reduce the files to an appropriate size for DVD quality. As for Blurays, I'd like to keep them at 1080p, since space isn't really an issue anyway. I don't see any reason to go down to 720p at this point. Any suggestions would be greatly appreciated, or if someone could point me towards some good reading to get started. For reference, to get the files I have now I used MakeMKV on my DVDs and ClownBD on my Blurays.

[hey]

There's absolutely no reason at all to leave them at those sizes. As long as your htpc isn't using a 20 year old cpu, you can reencode to hi10p. 10 bit compresses much better than 8 bit, and is also better quality. There's no hardware decoding for it yet though, so really shitty computers may not be able to handle it (my laptop running a 3 core phenom II at 2.2 ghz sometimes struggles with 1080p 5.1 flac and subtitles, but otherwise has no trouble).

[Obiron]

There's absolutely no reason at all to leave them at those sizes. As long as your htpc isn't using a 20 year old cpu, you can reencode to hi10p. 10 bit compresses much better than 8 bit, and is also better quality. There's no hardware decoding for it yet though, so really shitty computers may not be able to handle it (my laptop running a 3 core phenom II at 2.2 ghz sometimes struggles with 1080p 5.1 flac and subtitles, but otherwise has no trouble).

I built my HTPC around an Atom processor about a year ago (running XBMC). I haven't had any decoding issues yet, aside from an odd issue with some mkv files where I've had to pull the audio out, re-encode the mp3, then re-mux the mkv with the new audio file. I'll take a look at my exact processor and see if anything stands out as a decoding issue I would need to watch for, but flac and 1080p have both been great so far. Thanks for the tip.