Does 1080 produce higher web quality?

A

aaronriggs

New member
Has anyone ever noticed a relationship between web compression quality and starting resolution?
What I mean is, if I compress my footage for the web, does 1080 footage produce a cleaner image than 720... because there are more pixels/information to compress from? (Let's say my web resolution is 640x360)
Or is a good web compression dependent on other factors such as the codec the footage was shot in, bit rate on output, the web codec, ect?
Thanks
 
I can't say that it would produce higher quality when downscaled - but it would give you some assurance that your project will have some life in the future if you ever decide/need to release it via some other channel that might require higher resolution.

I'm curious why you would limit your web compression to 640x360 when sites like YouTube and Vimeo will display HD resolution?
 
All other things being equal, 1080 should produce a cleaner image when downscaled because any noise will be smaller in 1080 than it would be in 720.

But all other things are rarely equal.
 
Thanks for the responses.
Luis: The end product isn't intended for youtube or vimeo but rather a private website. But if I did shoot in 1080, you're right, it leaves the door open for output to youtube at it's highest quality.
Thanks
 
Keep in mind that if your bitrate isn't high enough 720P might look better because 1080 will have more detail and require more bitrate to keep the image about the same as the not compressed version.

If your bitrate is super obscenely high (like 15+ megabits) go for the higher resolution. But if you're around 3megabits, it might be benefical to scale down to 720P first then compress.
 
You also want to keep in mind that most cameras don't actually "resolve" to the full resolution that they record at. For example: any of the canon DSLR's may record to 1920x1080, but (according to some tests) don't actually resolve more than 700ish lines of resolution. This means that downscaling to 720p may not give any noticeable degradation to the image. In this case, at the same bitrate, the 720p is going to look better -- since the limited bandwidth is being used more efficiently on movement and not maintaining the higher pixel count.
 
tfg said:
You also want to keep in mind that most cameras don't actually "resolve" to the full resolution that they record at. For example: any of the canon DSLR's may record to 1920x1080, but (according to some tests) don't actually resolve more than 700ish lines of resolution. This means that downscaling to 720p may not give any noticeable degradation to the image. In this case, at the same bitrate, the 720p is going to look better -- since the limited bandwidth is being used more efficiently on movement and not maintaining the higher pixel count.
Click to expand...

You should still record at 1080P on those cameras since the pixel binning method does resolve more lines in 1080 mode than 720P mode.

I seem to remember that the Canon DSLRs could resolve about 800-850 lines of resolution, so the extra 1080P does give you a cleaner 720P image than recording just at 720P. I could be wrong.
 
Also the downscaling algorithm makes a difference.
Nearest neighbor. bilinear, bi-cubic or even with vector motion estimation (if you use Cuda acceleration and best quality in CS5).



Frank
 
How about 1080p vs 1080i?
I`m currently working with AVCHD 50i files with Vegas Movie Studio Platinum 10.
Now I`m wondering about buying/upgrading to Vegas Pro 10, because of the possibilities to work with 50p footage.
I`m gonna compress my footage for the web - for streaming and On-Demand Video.
Will there be a big difference in the images between 50p and 50i when you have compressed it? (I know there will be a difference, but is it big enough to buy the Pro version of Vegas?)

It may be a stupid question, but I`m a novice in HD production, coming from DV editing.
 
D'Amato said:
How about 1080p vs 1080i?
I`m currently working with AVCHD 50i files with Vegas Movie Studio Platinum 10.
Now I`m wondering about buying/upgrading to Vegas Pro 10, because of the possibilities to work with 50p footage.
I`m gonna compress my footage for the web - for streaming and On-Demand Video.
Will there be a big difference in the images between 50p and 50i when you have compressed it? (I know there will be a difference, but is it big enough to buy the Pro version of Vegas?)

It may be a stupid question, but I`m a novice in HD production, coming from DV editing.
Click to expand...


I think 1080p50 is supported in studio version , just not as a preset (you can enter custom values) - I remember someone asking about 1080p60, so it should work for 1080p50 too

Unless you do your own hosting, 30p is the max supported by sites like youtube, vimeo. So you would have to throw away 1/2 the data anyways for 1080p25

Also 1080p50 isn't a friendly streaming format - The bandwidth required for decent quality is too high, and flash playback can be choppy on many systems
 
D'Amato said:
How about 1080p vs 1080i?
I`m currently working with AVCHD 50i files with Vegas Movie Studio Platinum 10.
Now I`m wondering about buying/upgrading to Vegas Pro 10, because of the possibilities to work with 50p footage.
I`m gonna compress my footage for the web - for streaming and On-Demand Video.
Will there be a big difference in the images between 50p and 50i when you have compressed it? (I know there will be a difference, but is it big enough to buy the Pro version of Vegas?)

It may be a stupid question, but I`m a novice in HD production, coming from DV editing.
Click to expand...

if your footage originates at 50i footage, then buying Vegas Pro will not change anything. 50p is a different video format all together. You can convert your 50i footage into 50p by deinterlacing the footage during the compression stage. However, your resulted 50p footage will not look at good as footage that originated in 50p in the first place. It will still look better than keeping your footage in 50i format though, because computers monitors only display footage in progress (p) format properly.

Somewhat more in depth answer (but still trying to keep it basic):

Let's pretend you have a video that is shot at 1920x1080 50p. This literally means that there are 50 frames, at 1920x1080, per second.

Now let's pretend you have video that is shot at 1920x1080 50i. This actually means that you have "50 fields" - NOT frames, per second. What does that mean? Each "field" is actually half resolution (960x540). Field 1 is lines 1, 3, 5, etc, while Field 2 is lines 2, 4, 6, etc. These two fields alternate constantly, giving you the impression of watching 50 frames per second, but technically only being quick flickers of half-resolution at a time.

I'm not going to get more technical for now ... but so long as you grasp this basic concept: "progressive formats" 24p, 30p, 50p, 60p, etc, show full frames. "Interlaced formats" 50i, 60i (which are also called 25i or 29.97i at times) show 1 field at a time. You can de-interlace your "i" footage, effectively combining both fields into 1 full frame, but since those 2 fields actually originated from small different moments in time the result is going to add a fraction of blur. In essence, it will never be quite as crisp as something shot in progressive format in first place.

And just like the post above me said: 50p and 60p are not stream friendly formats anyway.
 
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