I've a question about downloaded 720P files

CorkMan

I download a movie (legally) a couple of hours ago over the internet. The movie is American Gangster and it 2 hours 55 minutes long. The size of the file is 7.95GB.

Is this real 720p? I heard "real" 720P is 50GB a disk! I am not sure though.

me-skywalker

CorkMan wrote: »

I download a movie (legally) a couple of hours ago over the internet. The movie is American Gangster and it 2 hours 55 minutes long. The size of the file is 7.95GB.

Is this real 720p? I heard "real" 720P is 50GB a disk! I am not sure though.

Neither am I.

Diddler82

me-skywalker wrote: »

Neither am I.

Thanks for your pointless input.

Yes it is...when it is on DVD it is a different format which is larger.

Similar to DVD's being 3 or 4 GB but in an Avi file they are 700mb mainly.

shinfujiwara

CorkMan wrote: »

I download a movie (legally) a couple of hours ago over the internet. The movie is American Gangster and it 2 hours 55 minutes long. The size of the file is 7.95GB.

Is this real 720p? I heard "real" 720P is 50GB a disk! I am not sure though.

25gb to 50gb are 1920x1080p videos (Full HD) stored in a Blu-Ray. Downloadable content (legally or illegally) are usually much less than that to facilitate streaming/downloading time.

Where did you download this? You usually can see informations like codec name and resolution of the file. But don't forget, what really matters is if you are pleased by the image quality of the video. Are you?

bnt

720P refers to the number of lines (720) and the way lines are encoded (Progressive (top to bottom in one frame) as opposed to Interlaced (every other line per frame). There are different methods of encoding video for Blu-Ray, but the main point to remember here is that the person/company doing the encoding can decide how aggressively to encode the video.

The 50GB capacity on the Blu-Ray can include more than just the movie: extras, multiple soundtracks, etc, and even then the manufacturer doesn't have to fill it all the way. Conversely, if you're encoding a video for internet distribution, you can choose to be more aggressive in the encoding with e.g. H.264. It throws away more of the video than normal, using all kinds of tricks to determine what's more or less important. 8GB for a feature is more compressed than Blu-Ray, but not that heavily compressed, so I expect it will look just fine.

me-skywalker

Diddler82 wrote: »

Thanks for your pointless input.

Yes it is...when it is on DVD it is a different format which is larger.

Similar to DVD's being 3 or 4 GB but in an Avi file they are 700mb mainly.

Your welcome.

Richard Dower

me-skywalker wrote: »

Your welcome.

Little git!

krudler

me-skywalker wrote: »

Your welcome.

You're

jaykhunter

I'll throw in my two cents. First off, yes, the file you downloaded is HD and most likely 720p.

I'd consider anything above 480p (the resolution of a DVD) to be HD; although in general it's accepted that HD has to be at least 720p.

Why the small file size?
The video has been compressed/decompressed to save space wherever it can so the file is smaller. Programs that do these are called codecs. When you see a video file of 8GB vs a BluRay of 25GB, the video file has been compressed, all the unneccessary information has been stripped out. Much like an mp3 of an album, it takes up a lot less space for about 90% of the quality, depending on how good your senses and equipment is.

It's akin to why an album on a CD would take up 700MB but an mp3 of the same album would be 70MB. They're trying to save space wherever they can.

The most noticeable area where they try to save space with a video file and it's noticeable is when the scene is dark. Compressed files have a lot of trouble getting good shades of black.

Anyway, long story short, your video file is HD/720p, but it's not "lossless", it's compressed to save space, unlike a Blu-Ray, which is uncompressed data, and huge!

Ghost Train

jaykhunter wrote: »

I'd consider anything above 480p (the resolution of a DVD) to be HD; although in general it's accepted that HD has to be at least 720p.
...
Anyway, long story short, your video file is HD/720p, but it's not "lossless", it's compressed to save space, unlike a Blu-Ray, which is uncompressed data, and huge!

So you would consider Pal DVDs to be HD?

Blu-ray uses lossy compression for it video but does support lossless for audio

It makes sense to compress internet and downloadable content more to save on bandwidth

BopNiblets

I've downloaded some encoded 720p vids that are from 1.5GBs to 3.5GBs, and they look great with no noticeable picture loss that I can tell, they don't all have to be massive!

jaykhunter

Ghost Train wrote: »

So you would consider Pal DVDs to be HD?

Blu-ray uses lossy compression for it video but does support lossless for audio

Ugh. No. I honestly didn't know DVDs can output higher than 480p. I'll have to use "higher than DVD specs" as the proper nomenclature from now on. In general i'd consider anything from a DVD-source to be SD and anything with higher than 480p resolution and from a HD source to be HD.

I'll clarify as well as Blu-Ray has the highest commonly available quality of video so I'd call that "lossless" although technically everything's somewhat compressed unless it's the original master print, which nobody on this board (and practically no-one in the entire freakin' world!) has access to.

shinfujiwara

jaykhunter wrote: »

Anyway, long story short, your video file is HD/720p, but it's not "lossless", it's compressed to save space, unlike a Blu-Ray, which is uncompressed data, and huge!

The videos inside a Blu-Ray are compressed too. Usually H.264 or VC-1 with a much higher bitrate (quality) than the ones that we download.

As far as I know only audio can be lossless in a Blu-Ray disc.

Richard Dower

Blu-Rays are only as good as the mastering and source material...never forget that!

shinfujiwara

Richard Dower wrote: »

Blu-Rays are only as good as the mastering and source material...never forget that!

What do you mean? That the video quality of a Blu-Ray is as good as the source material? If you meant that, I doubt it.

A professional movie must be pretty different from the movies that we make. Hard to believe that a source material would be 100% equal to a lossy 50gb encode. I can be wrong, considering that I never had the opportunity to see any source before, it's just way unlikely to me.

I've seen lots of blocks in some (bad) original Blu-Ray movies, which by my understanding does not exist in the source, right?

Suspiria79

Watched Iron Man 2 lately through the PS3. It was a 700MB 720p MKV file which I converted to MP4.
The quality was great all the way through, would notice the step up in quality for sure.