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ExtremeTech Wages War of the Codecs
prostoalex writes "ExtremeTech tested Windows Media, DivX, QuickTime/Sorenson and QuickTime/MPEG4 codecs. They encoded clips from Matrix Reloaded, Monsters, Inc., X2 and Spider-Man. QuickTime/Sorenson won the encoding speed contest, for the quality tests read the entire review, as each movie sample was encoded with 500KB and 1MB bitrates. Video samples provided on the site as well, so see for yourself."
They expect to have their opinion valued on Slashdot when they don't review the open source video codec? (It generally wins in other tests.)
Seriously, there is a program on Apple's site that will show any quicktime movie on the terminal. It renders a movie as characters on the terminal. Though if the movie is large then it tends to look bad since it doesn't wrap correctly.
I wonder how much better the QT/Sorenson and QT/MPEG4 (and maybe divX, dunno if there's an encoder) testing would have been if they were done on a Mac and the Velocity Engine could have been utilized?
One big factor which is neglected in this article is compatibility. I don't do too much with video files but a decent amount with audio and sometimes there are formats with minor quality differences, but what ultimately decides which to use is how many players can handle it easily. It doesn't come into consideration quite as much for personal archiving and controlled environments, but even then you can't tell what the future will bring and a little flexibilty now saves time later.
I don't try to be right, I just try to make people think
You only need to look at the scene to know what codec is in this month. It's Xvid by a long margin, most TV-shows (Stargate, Enterprise, whatever), DVD-rips, Anime etc. are encoded with it. MP3 and AC3 are predictably dominating the sound codec, with many TV-shows now also making the transition to full AC3 (well, the DVD rips of them at least).
Ok. encoding speed is somewhat important to a few people and bitrate is pretty important to most people but, quality is the most important to almost everyone. From a quality standpoint DivX is the clear winner. But, it still isn't broadcast quality let alone DVD quality.
Count me in as surprised at how poorly Apple's MPEG-4 implementation did. However, as a very new codec I expect it will improve in time. Or Apple will simply license someone else's codec.
Regardless, Apple has been one of the biggest supporters of MPEG-4, and I thank them for that.
I don't know what kind of crack I was on, but I suspect it was decaf.
Okay, I just encoded some DVD-size video at 1mbit and 500kbit, 1/4 size, in QuickTime MPEG-4 and can barely see any artifacts in either. This dude seriously got some settings wrong in his MPEG-4 encodings, although I don't quite see how that's possible as settings are quality, framerate, keyframes, and data rate (and he said quality was set at best). I'll post some screenies later if I get a chance.
The article's not very great. First, they convert the MPEG-2 stream to INDEO, then from INDEO to whatever the target is. Fine, but the process isn't a transitive one. Some codecs will not produce as good an input for other codecs, thus biasing the results.
What's particularly suspicious is that Apple's MPEG-4 came out so poorly, though WMV9, and DivX are nothing more than early MPEG-4 codecs. Sorensen3 is the only substantially different algorithm used. And why use MPEG-4? It was originally designed for low-resolution low-bitrate applications (PDAs, cell-phones, etc.)
Why so slow? I do most of my video transcoding under Linux, but they aren't getting much better throughput than I do, and their machine's at least 4 times as fast as mine? I suppose it's got to do with using Indeo (my source is DV), so there's an extra decode step, but it's still quite slow.
I've distributed a number of my own videos in the MPEG-4 format, and don't see the sort of horrible results they demonstrated in their examples -- but then again, perhaps I do preprocessing (quantization, denoising, etc.) that they don't include in their process.
Regardless, my personal experience is that at high or low bitrates, most of the codecs are interchangable. Perhaps you need to fiddle with the encoding parameters, but you can almost always get results close enough to identical as not to matter. It becomes more difficult with mid-range bitrates (2-3Mbps@720x480x29.97) that some codecs show strengths over the others. In that department, I almost always go with MPEG-2 with custom quantization matrices...
I mean MPEG-4, despite being open, is NOT a free format. You are required to pay licenses for encoders and decoders. Has XviD payed this? If not, it's technically not legal. That could keep it out of being a serious contender for pro use. I mean I'm betting the MPEG-4 group isn't going to care if some hobbiests are using an unlicensed encoder, but they'll care if pros are.
Does it tell you which codec is best? Maybe but only for recompressing MPEG-2 footage. They *should* have tested against DV output as the standard consumer format, and uncompressed video. Plus looking at snapshots of compressed movies is of limited value, there is a big difference between what detail we can determine through a still image and a moving one. If you were to freeze a tv picture (or look at a captured frame) which includes something moving you would see a combing effect of the interlaced video. It doesn't look like that when you view it though.
Apple's MPEG-4 has both a mediocre encoder and decoder. 3ivx is a much better choice, it both decodes MPEG4 (and Divx/XviD) with better postfilters (the best, argurably), even scaled to how much CPU time it can grab. Its encoder is extremely nice, and very userfriendly, and it's extremely high quality. (And before you point Doom9's tests, Doom9 has NOT been configuring 3ivx correctly, so he's shooting himself in the foot). It has a 'trial' codec free (no real restrictions, but only for 'trial use') available for both Windows, Mac, and even BeOS (older versions are available for Linux and other platforms).
Referring about Sorenson, keep in mind this is the FREE codec that comes with Quicktime Pro. Professionals use a several hundred dollar 'Developers Edition' with Cleaner (two pass VBR encoding, which makes Sorenson rock). I know this is a for-user comparison, but in the professional scene, Sorenson can be even better then third/second place in quality.
I have tried using DiVX and Apple's MPEG4 to encode a short video and there are just far too many options to play with. It's virtually impossible for the average person to use any of these and get great results. We need something that will produce excellent results at the click of a button. Until then I'll stick to showing my digital videos saved back to the camera, plugged into a TV, where quality is fantastic.
--- What?
He pondered that the testing might have been better on the Mac because of the Velocity Engine available on G4 & G5 processors which would make it much faster. He never said the video quality would be better, jackass.
I have a website. It's about Macs.