So youtube offer four video formats: 3GP, FLV, MP4, and WebM, with range of resolutions between 144p - 720p.
For example, this youtube link will gave these selection download links in keepvid.com:
» Download 3GP « - 144p - 4.0 MB
» Download 3GP « - 240p - 11.2 MB
» Download FLV « - 240p - 16.9 MB
» Download FLV « - 360p - 25.3 MB
» Download FLV « - 480p - 38.3 MB
» Download MP4 « - (Max 480p) - 22.9 MB => (Note: after downloaded, I found out it's actually 360p)
» Download MP4 « - 720p - 68.1 MB
» Download WebM « - 360p - 33.8 MB
» Download WebM « - 480p - 53.3 MB
» Download WebM « - 720p - 82.9 MB
The question is very simple, what should I pick from above selections to get the best quality video?
Of course, 3GP are opted out immediately because they have too low resolutions.
People might suggest to take the 720p with the logic "highest resolution=highest quality", but after I downloaded them, I found out the 720p video looked more ugly than the lower resolution videos (I don't know the term for this, but the 720p video showed the artifact or jagging line more clearly). It seems 360p has the best looking video display. Probably the original uploaded video resolution is around 360p, so that's why it looks bad in higher resolution.
How about 480p video? Well, it turned out there are only two options: FLV (480p) and WebM (480p). Since WebM is not good (I had explained before), so there is only one option: the FLV. When I compared FLV (480p) with FLV (360p) and MP4 (360p), it seems 360p videos are better, although in some frames, FLV (480p) can look better. Currently, I choose to opt out FLV (480p) for sake of convenience. I want to focus on 360p first.
Now, I'm confused to choose between FLV (360p), MP4 (360p), or WebM (360p). I compared them by playing and stopping the video in same frame and looking at each of them (I'm using MPC-HC from K-Lite Mega Codec Pack for the video player). I found out WebM is kinda jagged although it has the biggest filesize among three. So I decided to opt out WebM.
Now, it's between FLV (360p) and MP4 (360p). When I'm seeing both of them carefully, they seems equal in sense of numbers of artifact shown but in different frames. So, for example the FLV has artifacts in frame 300-400. But in same frame range, the MP4 showed smoother frames, however in different frame like 600-800, the MP4 shown artifacts and FLV is smoother. Of course, there is no way I would check and compare the video frames one-by-one. So, I'm thinking there must be the other way.
Here are the MediaInfo from both videos (note: I trimmed the Audio info because it's unnecessary):
1. FLV (360p)
2. MP4 (360p)Code:Format : Flash Video File size : 25.3 MiB Duration : 6mn 47s Overall bit rate : 521 Kbps httphostheader : o-o---preferred---sn-4pgnuhxqp5-jb3e---v19---lscache2.c.youtube.com Video Format : AVC Format/Info : Advanced Video Codec Format profile : Main@L2.2 Format settings, CABAC : Yes Format settings, ReFrames : 3 frames Codec ID : 7 Duration : 6mn 47s Bit rate : 386 Kbps Width : 640 pixels Height : 360 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 14.970 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.112 Stream size : 18.7 MiB (74%)
From above informations, it seems FLV has slightly higher video bitrate than the MP4 (386 Kbps vs 374 Kbps), however MP4 has Variable Frame Rate Mode. I'm not expert in multimedia, but I want to know, does higher bitrate from above two videos prove it has better quality? Does Variable Frame Rate Mode might produces better quality display? Any advices?Code:Format : MPEG-4 Format profile : Base Media / Version 2 Codec ID : mp42 File size : 22.9 MiB Duration : 6mn 47s Overall bit rate mode : Variable Overall bit rate : 472 Kbps Encoded date : UTC 2012-03-01 07:07:34 Tagged date : UTC 2012-03-01 07:07:34 gsst : 0 gstd : 407463 gssd : B6F5EF804HH1348909191457421 gshh : o-o---preferred---sn-4pgnuhxqp5-jb3e---v7---lscache8.c.youtube.com Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : Baseline@L2.2 Format settings, CABAC : No Format settings, ReFrames : 1 frame Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 6mn 47s Bit rate : 374 Kbps Maximum bit rate : 976 Kbps Width : 640 pixels Height : 360 pixels Display aspect ratio : 16:9 Frame rate mode : Variable Frame rate : 14.971 fps Minimum frame rate : 10.000 fps Maximum frame rate : 15.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.108 Stream size : 18.2 MiB (79%)
So basically, anyone can help me to choose the best quality video from the above download selections? Also, anyone can share how to compare quality between different resolution videos, such as: 360p and 480p?
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Last edited by ohboy888; 30th Sep 2012 at 09:15.
You cannot tell the quality of any video before seeing it. But generally:
At the same bitrate, MPEG 4 part 10 (h.264, AVC) can be better than MPEG 4 part 2 (Xvid, Divx) can be better than MPEG 2.
VFR can be better than CFR at the same bitrate.
Within a particular codec higher bitrates deliver better quality. But the particular settings used during encoding can make a big difference.
Different videos may do better with some settings than others.
Last edited by jagabo; 29th Sep 2012 at 10:59.
From what I have seen, unless a 1080p option is available, the 720p is likely to be an up-scaled version of a DVD, or even worse, a VCD.
Watch your shortlisted versions full-screen on Youtube , you will find it easier to differentiate between them.
In the specific case you have mentioned, since 1080p is not available, I would just compare the flv 480p and 360p versions and decide.
^ It seems to depend on the uploader, if they upload upscaled 720p then thats what YT will display. I've uploaded captured 720p and YT displayed it as such and not as upscaled SD.
Thanks for your information. Between FLV (360p) and MP4 (360p), the video bitrate differences is not so big, and the MP4 has VFR, so it seems MP4 (360p) might be the best choice for now.
Between FLV (360p), FLV (480p), and MP4 (360p) at some frames, MP4 (360p) tends to display smoother frame while the others are showing jagged pixels. I don't know if the smoother frames in MP4 is because of VFR encoding, although unfortunately it doesn't happen in MP4 (720p). I'm thinking MP4 (360p) is better than FLV (480p) although the bigger/480p resolution is kinda tempting me.
If maximum available video resolution on a youtube video is 720p, could that mean the original uploaded video resolution is 720p too?
Why don't you give us a concrete example? A link to the video you're talking about.
Another thing you need to keep in mind is that Youtube has used different codecs over the years. So different videos may have different codecs in the files.
Ah, I tried the individual links but they didn't work (their specific to your IP address). The 720p video was poorly upscaled from a standard definition interlaced video. I downloaded a couple of the 640x360 versions, one FLV the other MP4. They looked about the same. They're all pretty poor quality, jerky ~15 fps, bitrate starved.
It was probably originally 720x576 interlaced and was upscaled to 1280x720 without taking into account it was interlaced.
If you're going to watch the video full screen pick the 640x360 version. Of the two I saw the 640x360 had much less artifacting. But the 240p video was sorensen spark, not avc.
I got reply from the uploader, it's true that he had compressed and then upscaled the video.
I'm curious, let's say the youtube video is directly uploaded from the source (no upscaling, etc). What would you pick? I guess the prominent choices would be between MP4 and WebM at the highest resolution.
For example is this youtube video:
By comparing above video between MP4 (1080p) and WebM (1080p), MP4 is still smoother at some frames than WebM. Whatever resolutions WebM has and despite of the big filesize it has, WebM is always a bit inferior to MP4 at same resolution from my comparison.
Anything you can tell about WebM (VP8)? Could it be true that MPEG 4 part 10 (h.264, AVC) is better than WebM?
Last edited by ohboy888; 2nd Oct 2012 at 06:18.
h.264 is superior to VP8.
^lol, there must be a good side in WebM, if not why the filesize is so big?
Better compression implies better quality at the same bitrate.
But youtube usually allocates more bitrate to the webm versions, so it might not be clear which is better on youtube. Some sections maybe better, some worse. Again, you have to use your eyes, you cannot just pick beforehand.
The audio is usually better on the webm versions as well (YT usually gives them more bitrate as well). Some people think it's a conspiracy to push more acceptance for webm
sorry to jump in like this.. but, is there an ¶meter one can add in the YT url to get other the standard video format YT dishes out ?
i seem to only get flv and avc although i mainly default to the 360p on account of my slower internet (dsl) speed. i wouldn't mind checking out the webm version if i can change modes freely, tx.
regarding the posted clip.. its mostly very bright and the darks seem to be too dark (0-255) so that may account for why you see less artifacts, hence perceived better quality. still, its a good video to snip for my library, ty.
but even the pullups don't show the format (webm, avc, flv) just the size.
edit 1: let me search around google then, maybe i will come up with something, tx anyway.
edit 2: found this, so far..but doesn't give vid format..still searching..
/********************************************** // 2010.12.22 list of video formats // fmt=5 240p vq=small flv // fmt=18 240p or 360p vq=medium mp4 // fmt=34 240p or 360p vq=medium flv // fmt=35 480p vq=large flv // fmt=22 720p vq=hd720 mp4 // fmt=37 1080p vq=hd1080 mp4 ***********************************************/
maybe it is for select videos then. i would like to test some scenarios out. are there any known YT urls that have webm clips? preferably very short clips ?
The fmt codes are old - they no longer work for over year now
flash video downloader plugin for firefox will display all options you can download, but you have to visit the YT page (and it starts loading /playing the default video)
jdownloader has a youtube parser and will show all versions as well, format and filesizes. The benefit of jdownloader is no video is downloaded automatically , no extra bandwidth wasted (you don't have to visit the youtube page, as it automatically starts playing and wastes bandwidth if it's not the version you want) . The negative is it relies on java, and is quite bloated
pdr, can you post the exact search term you used for that pic above ? or, what is that exact YT video url in that clip ?
i'd like to test a theory, tx.
edit: this is not working "bubaran kantor eps pura-pura bunuh diri part 2"
Last edited by vhelp; 2nd Oct 2012 at 13:26.
tx, that worked.
Well, if you have to choose, what version would you choose?
H.264 is supported by many portable devices (HW decoding) i.e. long lasting batteries due lower power consumption so H.264 seems to be optimal choice (anyway user already paid licensee fee buying device capable to H.264 decode so there is no argument for VP8 that VP8 is for free).