Xvid and h264

[Mr Bland]

What exactly are they and what is the difference? Is one better than the other (ie quality or resolution?)

[Ledgem]

These are video codecs. You're probably familiar with JPEG, GIF, and PNG - the three of those are formats that pictures are compressed in. XviD, DivX, and H.264 are somewhat analogous to those formats but are used for video. Uncompressed video could easily take up a few gigabytes for a clip that is a mere 30 seconds long. The codecs are used to keep the file size low, at the expense of some quality loss.

The difference lies in the algorithm used to encode frames, among a number of complicated things that I don't know much about (frames are just the surface and are rather easy to understand, as one frame is essentially one picture). XviD is an older codec, whereas H.264 is newer. XviD's compression is a bit weaker than H.264. In general, if you wanted to get a video of the same quality encoded with XviD and another encoded with H.264, you could expect to find that the XviD-coded video has a larger filesize than the H.264-coded video. Put another way, if both files had the same file size, you would expect that the H.264-encoded video had less quality loss. H.264 uses a more intensive compression, which requires a more powerful computer to decode compared with XviD.

Resolution is not effected by the use of either. You can expect to lose less quality while keeping file sizes reasonable with H.264 when compared to XviD.

[emptyeighty]

Xvid and Divx are de-/encoders based on the MPEG-4 Part 2 (ASP) standard, while H.264 is the ITU-T name for the MPEG-4 Part 10 (AVC) standard. AVC is newer and more advanced than ASP, therefore giving better results at the cost of slower de-/encoding.

[neqael]

Agreeing with the posts above. To simplify things you can assume that something encoded using XviD and the same thing encoded using h.264 but taking up half the file-size of the first one will be roughly the same quality. That was the goal at least . So, generally, if your computer is capable enough to play it smoothly, you'll always want everything in h.264. Hope that helps.

[martino]

Originally Posted by neqael

To simplify things you can assume that something encoded using XviD and the same thing encoded using h.264 but taking up half the file-size of the first one will be roughly the same quality.

Sometimes even better.

[WanderingKnight]

Kinda hijacking the question here, but I wonder if we'll ever get to the point, in terms of storage space, when we won't need to compress video anymore.

I'm sure there will still be encoding options available to make up for the source's flaws, but still... makes me wonder.

[martino]

Storage probably wouldn't be a huge problem. Internet bandwidth yes.

[Sides]

Originally Posted by WanderingKnight

Kinda hijacking the question here, but I wonder if we'll ever get to the point, in terms of storage space, when we won't need to compress video anymore.

I'm sure there will still be encoding options available to make up for the source's flaws, but still... makes me wonder.

In what kind of context are you refering to?
I mean master recordings are stored either in raw formats or store in a lossless format. But for broadcasting bandwith is important, so you do want to use somekind of lossy compression to save as much bandwith you can.

[Eisdrache]

Not exactly the same question, but I often see when getting subs from several groups, that the h264 file is 50-100MB bigger then the avi one. After reading this thread, shouldnt it be the other way around for same quality, or at least the same file size for better quality in h264?

[AceD]

Originally Posted by Eisdrache

Not exactly the same question, but I often see when getting subs from several groups, that the h264 file is 50-100MB bigger then the avi one. After reading this thread, shouldnt it be the other way around for same quality, or at least the same file size for better quality in h264?

xvid codec in an avi container, will never be as good as H264 in a matroska, unless the size of the xvid is huge...talking gigabytes

also most h264's these days, are 720p high-def , i believe you cant do that with Xvid (again...unless the file size is stupid big, never seen a 720p in xvid actually...)

h264 requires a fast pc processor...dualcore normally

basically only watch xvid if you have small harddrives and are storing your anime, your PC is crap. your montior is tiny and cant reach the required res for 720p...


all in all, you gotta be a mug to be watching XVID, unless your PC simply cant handle H264...

[WanderingKnight]

h264 requires a fast pc processor...dualcore normally

Nope. I'm fairly capable of decoding 720p files smoothly on an old Athlon XP 1.5 GHz. Sometimes I need to disable the loop filter with some particularly pesky encodes but most of the times I can do pretty well without that workaround.

But then again, I use a sane operating system.

[martino]

Originally Posted by Voracious Hollow

basically only watch xvid if you have small harddrives and are storing your anime

Errr no? H.264 encodes will often be smaller at the same resolution.

[emptyeighty]

Originally Posted by Voracious Hollow

h264 requires a fast pc processor...dualcore normally

SD H.264 happily plays on my trusty old Athlon 750MHz, which dates back to 2000. 720p and above is another matter entirely of course.

[AceD]

Originally Posted by emptyeighty

SD H.264 happily plays on my trusty old Athlon 750MHz, which dates back to 2000. 720p and above is another matter entirely of course.

always paused alot on my old AMD2500 (which was overclocked to 3200 for gaming purposes), well thats my experience...

Originally Posted by martino

Errr no? H.264 encodes will often be smaller at the same resolution.

most h264 encodes are 1280x720 for 720p purposes...find me an anime thats in xvid and encoded at 1280x720? ive never seen one to compare

might be true if your downloading h264s at summin like 800x400 or whatever is it...but why would someone encode h264 at that

[martino]

Originally Posted by Voracious Hollow

most h264 encodes are 1280x720 for 720p purposes...find me an anime thats in xvid and encoded at 1280x720? ive never seen one to compare

Originally Posted by Voracious Hollow

might be true if your downloading h264s at summin like 800x400 or whatever is it...but why would someone encode h264 at that

You've not been watching fansubs for long enough. Go back a year or two and that was something that you'd have seen around (although at that time most of them were upscales and blahblahblah). And people still and always will encode H.264 videos at resolutions other than 1280x720. H.264 is not a format _only_ for HD encodes or w/e you wanna call them.

[Sides]

Originally Posted by Voracious Hollow

most h264 encodes are 1280x720 for 720p purposes...find me an anime thats in xvid and encoded at 1280x720? ive never seen one to compare

Fire up share, winny or perfect dark. Most 1280x720 files are encoded in divx, ok not xvid, but still mpeg4 (A)SP. Some people actually share both types, x264 and divx, so if you want you can get both types from the same provider and compare it.

[Sci-Fi]

Originally Posted by emptyeighty

SD H.264 happily plays on my trusty old Athlon 750MHz, which dates back to 2000. 720p and above is another matter entirely of course.

You could apply the same problems on older computers for 1280x720 xvid/divx files.

[Sci-Fi]

Originally Posted by martino

Errr no? H.264 encodes will often be smaller at the same resolution.

That's not necessarily true. There's one anime that everybody is using the 'exact' same ts source to make the HD version (720p/1280x720) and the xvid version is the smaller file size. Which one (the various mkv encodes, mp4, and xvid) is closest to the original source is a matter of opinion and people may like one encoder group over another.

[Craymel]

Originally Posted by Sci-Fi

That's not necessarily true. There's one anime that everybody is using the 'exact' same ts source to make the HD version (720p/1280x720) and the xvid version is the smaller file size. Which one (the various mkv encodes, mp4, and xvid) is closest to the original source is a matter of opinion and people may like one encoder group over another.

Actually, at the same resolution h.264 encodes can be higher quality with a smaller file size then xvid encodes. What size the files are however is always up to the encoder.

[martino]

Originally Posted by Sci-Fi

That's not necessarily true. There's one anime that everybody is using the 'exact' same ts source to make the HD version (720p/1280x720) and the xvid version is the smaller file size. Which one (the various mkv encodes, mp4, and xvid) is closest to the original source is a matter of opinion and people may like one encoder group over another.

You misunderstood my post.

Originally Posted by martino

Errr no? H.264 encodes will often be smaller at the same resolution.