Does Youtube Encode Uploaded Videos at Their Own Bitrate?
Author'due south Annotation (March 15, 2022): A colleague recently advised me that YouTube was now encoding all videos into VP9 format. A quick cheque revealed that he was correct; literally every video that I checked, including some uploaded back in 2010, was encoded into VP9 every bit well as H.264.
What'south interesting is that many low-volume videos, like this i with 118 views that I uploaded in 2010, displayed H.264 even though there was a VP9 version available with a lower bitrate.
Here'south the file list produced by YouTube-dl. Notation that the MP4 file using the avc1 codec has a bitrate of 2310 kbps, while the webm VP9 file has a bitrate of 1505 kbps. Why would YouTube produce a VP9 with a lower bitrate and and so not stream information technology?
To verify this behavior, I loaded all the files contained in Table 6 below. All continued to display avc1 according to Stats for Nerds though all had VP9 encodes. As above, this happened fifty-fifty when the VP9 encoded file had a much lower bitrate.
The other major change that I noticed was that AV1 usage had been pushed to very low view counts. Table 4 from the original article showed that all Seth Meyers videos, even those with multiple million view counts, were encoded to VP9. This time around, every Meyers video that I checked used AV1.
As shown in Tabular array v below, when I concluding checked, all Dan Patrick videos, which had view counts ranging into the low twenty thousand, were encoded with VP9. When I checked today, several Dan Patrick videos with view counts in the mid-teens were encoded with aV1, like this ane. That'due south a remarkable change.
What does this all mean? It may be time to rethink deploying VP9, AV1, or both.
Also, it ways that most of the data below is obsolete and, at to the lowest degree every bit it relates to the carve up between H.264 and VP9, may accept been incorrect in the kickoff place. I didn't know about youtube-dl when I wrote this first article and causeless that YouTube didn't stream VP9 for low view count videos because they didn't encode with that codec.
Now we know that for certain videos, YouTube still streams H.264 even when VP9 is available. Then, when I tested concluding August, YouTube could have been producing VP9 encodes for the files listed in Table 6 and but not streaming them.
As of today:
- YouTube encodes all videos with the VP9 codec, merely for some reason displays H.264 for low view count videos.
- YouTube deploys the AV1 codec at much, much lower view counts than reported beneath.
This article reviews which codecs YouTube uses for the unrelenting torrent of videos that it ingests and encodes. The data propose that AV1 is just worthwhile for videos with view counts in the mid-to-high millions, simply VP9 is worth because for view counts in backlog of a few thousand.
Equally a general rule, if YouTube can't beget to use a particular codec, chances are you tin't afford to use information technology either. On the other mitt, if YouTube is starting to employ a codec for videos with moderate view counts, possibly it'south interesting for you besides.
This article explores which codecs YouTube uses for the different videos uploaded to the service and their respective view counts. By way of background, I was trolling YouTube and the fabulous Stats for Nerds feature for a lesson that I'k producing for a new grade. The object of the practise was to ascertain the breakeven points that seem to dictate codec usage.
Encoding Cost and Bandwidth Savings
In terms of price/quality tradeoffs, the concluding time I looked, AV1 (libaom-AV1) took about 18 times longer to encode than H.264 (x264), which translates directly into xviii times the encoding cost if you're running your own encoding subcontract, which YouTube does. In contrast, VP9 (libvpx-VP9) took only twice every bit long as H.264. At best, I establish that VP9 saved about 15% over x264 while AV1 shaved 45% at the same quality level.
How do these quality/bandwidth savings numbers translate to codec usage for YouTube, which ingests a mind-boggling 500 hours of video per minute? The TL/DR is that YouTube uses H.264 for the vast majority of videos that might get watched a few hundred times, or even lower. Starting in the 3-5,000 range, YouTube starts to apply VP9, with AV1 reserved but for videos that will probable exceed more than five 1000000 views or and then.
Of course, mayhap Google's Argos Video Coding Unit, which Google developed specifically to procedure video, is responsible for what appears to be a dramatic change of beliefs relating to VP9 usage. AFAIK, there's only one other VP9 hardware accelerator (from Xilinx past fashion of NGCodec) and information technology's for live video and isn't commercially bachelor. So, even if YouTube uses VP9 for insufficiently depression view counts, it might not make sense for others without hardware-accelerated VP9 encoding.
AV1 for Multiple Million View Counts
Permit'due south start at the meridian. Clicking Explore then Music, I checked the top ten "hottest videos of the week" in the music department. Nigh of these videos were newly released, yet many had over 5 1000000 views. Eight of the ten videos were encoded using the AV1 codec; the residual were VP9. Interestingly, YouTube whiffed on the fabled Olivia Rodrigo video (it is cruel out there), which was top of the list and had over 9.6 million views and counting.
VP9 for Multiple Thousand View Counts
Adjacent, I checked the height 10 news videos, all with much lower view count, and with much shorter legs than other categories that I checked (news beingness topical and all that). Though the view count ranged from four,582 to 673,454, YouTube encoded all videos using the VP9 codec.
Next, I checked gaming videos, which enjoy greater view counts than news and presumably longer tails. Here we saw an even divide between AV1 and VP9. The option of codec sometimes made sense (come across the lesser three) though using VP9 for Call of Duty and LEGO had me shaking my head.
Side by side, I hunted around for an entertainment site with moderate to high views and settled on Late Night with Seth Meyers, apparently the new domicile for Mr. Meyers who I'chiliad certain we all remember from Sabbatum Nighttime Live. A line of videos entitled A Closer Look enjoyed very solid view counts in the low millions, yet YouTube encoded them all in VP9.
My favorite website for sports clips while working out is the Dan Patrick show; Numbers hither were pocket-sized merely VP9 was again used for all videos.
H.264 For the Nifty Unwashed
Finally, I looked at the videos that I produced, all with pathetic view counts (note to self: burn marketing manager). Every bit you lot can see below, it was all H.264. I checked Streaming Media's YouTube videos which enjoyed counts into the low several hundred and they were all H.264 also.
The Lesser Line
The lesser line appears to exist:
- View counts below a few thousand – use H.264.
- View counts reaching into the mid-5 figures, say over 3,000 or and so – consider VP9. Over again, since Google's use of VP9 may be triggered by the Argos VCU, yous should do your own testing with your encoding setup to confirm this event.
- Don't consider AV1 until view counts exceed multiple millions.
The large surprise for me wasn't the AV1 findings, merely that YouTube uses VP9 so extensively. When I analyzed VP9, the results were meh (see here). It may be that YouTube is using a different VP9 codec than I tested, or that YouTube is simply better at encoding VP9. Any the cause, given that YouTube'southward bandwidth costs are probably a lot lower than yours (per GB), it should take you lot fewer viewing hours to reach breakeven, meaning that information technology might be time to rethink VP9.
Resource
Real-Globe Bandwidth Savings from VP9, HEVC, and AV1
Computing Breakeven on New Codec Deployments
How to predict codec success – Techradar Pro, Dec 2020.
murphycomenclater.blogspot.com
Source: https://streaminglearningcenter.com/codecs/which-codecs-does-youtube-use.html
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