My video looks crappy on my computer... what's wrong?
Most video compression is lossy, i.e. it operates on the premise that much of the data present before compression is not necessary for achieving good perceptual quality. For example, DVDs use a video coding standard called MPEG-2 that can compress ~2 hours of video data by 15 to 30 times while still producing a picture quality that is generally considered high quality for standard-definition video. Video compression, like data compression, is a tradeoff between disk space, video quality and the cost of hardware required to decompress the video in a reasonable time. However, if the video is overcompressed in a lossy manner, visible (and sometimes distracting) compression artifacts can appear.
A compression artifact (or artefact) is the result of an aggressive data compression scheme applied to an image, audio, or video that discards some data which is determined by an algorithm to be of lesser importance to the overall content but which is nonetheless discernible and objectionable to the user. Artifacts in time-dependent data such as audio or video are often a result of the latent error in lossy data compression.
Technically speaking, a compression artifact is a particular class of data error that is usually the consequence of quantization in lossy data compression. Where transform coding is used, they typically assume the form of one of the basis functions of the coder's transform space.
Compression artifacts occur in many common media such as DVDs, common computer file formats such as JPEG, MP3, or MPEG files, and Sony's ATRAC compression algorithm. Uncompressed media (such as on Laserdiscs, Audio CDs, and WAV files) or losslessly compressed media (FLAC, PNG, etc.) do not suffer from compression artifacts unless they were encoded from a compressed source.
I wonder if this applies to Final Cut files saved on common media such as Maxell DVD-R's? I love wikipedia!
...and I'm bored...
15 comments:
Most definitely applies...
I've been compressing through trial and error and tons of research, and so far, the best explanation I've come across as to why the video looks like shit on YouTube is this:
The uncompressed QuickTime file that FCP is outputting is 500 mb or so. That's a lot of information for a 2 and a half minute video, which makes sense if you consider that the more motion and color there is, the more information there is to process.
A 2 and a half minute video of a person against a white wall who only moves their hand once won't be 500 mb - hell, it won't even be 200, most likely. The 0's and 1's that make up the information in our video are constantly changing, as opposed to the 0's and 1's of a person against a white wall - there's not as much variance.
As it stands, the Betacam transfer for TV is as we saw on Flip's comp (so I'm told), as it was intended to be, since that's what we shot it for. The DVD and Web versions are trickier because of what I've just said.
I explained to Poti that Youtube's automatic compressor is very indiscriminate as to how it compresses. Tenemos que darle algo ya masticado para que nada mas lo tire sin que tenga que hacer mucha compresión.
I'm still working at it. Wish it could be faster, but compression and uploads take time. I'm really sorry it wasn't something that we took into consideration before shooting, it never ocurred to us that it'd be this big or time consuming an issue. Please bear with us, nobody wants a crappy pixelated version of something we've all busted our balls over to be floating around the net.
In the meantime, there are a few alternatives to Youtube for web videos that I've also been exploring - more on that after I talk to P in a bit.
Again, my apologies for this bullshit...
-M
ze sharc- i believe you.
Aight. Tis up on my Facebook profile, looks much better than YT. Poti is uploading the same one into the Lemmi group on FB. Let the video load almost completely before you hit play so you don't get any lag.
Thankfully, the DVD is not an issue - Poti burned it again from the original file with Toast 8 (maybe that was the kicker), and it looks broadcast quality.
I also showed Poti a site that's like YouTube but for DivX quality files. If anyone here's ever downloaded a properly compressed film or TV show, then they know what I'm talking about. The trade off is that it takes longer to load, but it's widespread and most people have the DivX codec already (and if they don't, it's free). I'll be compressing for that shortly and let you know as soon as it's uploaded.
Still going to work on a YT compression, though.
Almost there, guys.
-M
At Rat's request, it's been taken down from Facebook.
1. Isabel, referring to the corrupted shots, skipping parts, and ghosting (specifically) said it looked 'unfinished.' She saw it as soon as it was posted. She told me this after I asked it be taken off.
I don't want that piece of shit compression to be the first impression people get of the video.
2. It should be uploaded by the band, on their profile page. Not on Marc's or mine, or anyone else's. At least not until everyone is bored of seeing it.
This is Lemmiwink's video.
To promote the band.
3. It looked like a shit sandwich. Like crap on a bad hair day. Like Anna Nicole Smith's liposuctioned blubber. Like the pendejos covering my balls. Like Steve Buscemi. Like The Tulivieja's picture. Like 2 girls 1 cup and goatze's bastard child.
etc.
etc.
etc.
Poti,
Tu me dijiste que hiciste el dvd de otro file que hizo Flip, y no del original que fue descrito en el punto 3 del cometario anterior.
Es correcto esto?
Still, Isabel said it was the best video ever, aside from the compression bullshit.
best video ever... that is unfinished. yes, u are correct. ta en un dvd and it looks good over here, even in my computer.
veremos que pasa mañana.
and i dont think its wise to make fun of anna nicole... she is dead now and she was a good person... with huge tits.
Rat, DVD of Flip's most recent compression looks great on all TV's I have tried in my house. Including the flat screen which is the same one you have, no pillar boxing. Broadcast quality all around. Expect a copy in the mail.
wanna see video. Put up on blog!
I want some stillnox!
cant believe my anna nicole joke is getting no laughs.
I laughed. On the inside.
me too
http://www.1030films.com
Good Quicktime version up there, let it load about 75% before before you hit play, it´s got a fairly high bitrate.
DivX coming soon. Love the responses we're getting. Kick ass.
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