Whay are my rendered files so large?

[Billy Ramone]

Hello, great and powerful Adobe community.  I'm finding that no matter how I tweak my render settings, my video file sizes seem unreasonably large.  For example, today I rendered a 1hr Premier Pro edit using Media Encoder's YouTube 1080HD export preset, which produced a 1.8Gb file.  When I upload this 1.8Gb file to YouTube and then download it, the downloaded file is only 89Mb.  Seems like a huge disparity considering I'm using an export setting presumably optimized for YouTube specifically.  As you can see from my settings (below) I've got the target bitrates cranked down pretty low, to the point that the video quality already takes a noticable hit.  Any lower and the video quality is just poor.  What is YouTube doing to squish my 1.8Gb file down to 89Mb?  I notice a lot of 1080 video on YouTube looks crystle clear.  How can I acheive these small file sizes and still get acceptable video quality from Adobe Media encoder?

- Preset Used: Custom
- Video: 1920x1080 (1.0), 25 fps, Progressive, 203 (75% HLG, 58% PQ), Software Encoding, 01:08:06:02
- Audio: AAC, 320 kbps, 48 kHz, Stereo
- Bitrate: VBR, 2 pass, Target 4.00 Mbps, Max 6.00 Mbps
- Encoding Time: 00:46:52

This particular example is a little odd because the source video was downloaded from WebEx, so the quality was iffy to begin with, but that doesn't explain the bloated file sizes.  In fact, since the video content was just PowerPoint slides with audio, I'd actually expect better compression since there's hardly any motion in the video at all.  Can someone give me a hint as to what I'm missing here?  Any insight would be greatly appreciated.

Thanks!

[Warren Heaton]

Hi @Billy Ramone 

As you've noticed, video files can be very large.

The file size is a direct result of the settings used for video and audio.

Here's a storage calculator that you can plug your settings into to get an idea of the file size you can expect from Premiere Pro or any applicatoin that encodes video.

https://www.digitalrebellion.com/webapps/videocalc

To get a sense of files sizes to expect based on common video file formats, I like to use Digital Rebellion's storage calculator.
https://www.digitalrebellion.com/webapps/videocalc

Have you tried H265 instead of H264?  At the same settings, it should be about 60% the file size that H264 would have been.

You could also try switching to Hardware H264 encoding if that is available on you workstation.  You may have to switch to 1-Pass ecoding for it.

For 1080p25, a target of 4 Mbps with a maximum of 6 Mbps is low and may result in picture quality loss.  While it means a larger file, I'd bring that up to at least 10 as the target and 12 as the maximum.


- Warren

[Billy Ramone]

Thanks, Warren.  I really appreciate you taking the time to respond.  I think you've misread my question, though.  What I want to know is - if YouTube can shrink my 2Gb file down to 150Mb and still preserve decent video quality, why can't I render good looking 150Mb file directly from Media Encoder?  I mean, that disparity is huge.  No matter what I do with Media Encoders render settings, I can't anywhere near 150Mb without rendering a pixelated mess.  I can't even get under 1Gb without a serious loss in quality.  I posted this question in the Premier forum also and was basically told that Media Encoder just isn't a very good compression engine, which was disappointing.  If YouTube's compression algorithm can get me 150Mb where AME can only get me down to 2Gb, then YouTube must be magic.  It was suggested that I invest in third-party compression software, so I'm looking into options.

If you can suggest specific export settings I should look at to improve my results (other than bitrate), I'm wide open to suggestions.  In any case, I sincerely thank you for the input.  I've been posting here for 25 years and it's always a positive experience.  

[Warren Heaton]

It can seem like magic, sure.

Hardware encoding at a low bit rate is what's going to keep the file size small - just be sure to balance that with picture quality and the intended use of the resulting file.  

For a 1 hour 8 minute video to come in at 150 MB, the bit rate for picture and sound would need to be around 0.33 Mbps (or 330 Kbps).

I see 330 Kbps working for 240p25 or 320p25 (settings common for web video and CD-ROM video about 25 years ago), but not 1080p25.

To take a close look at a 150 MB video file, open it in MediaInfo and review the file's details.  You could then try to match those settings in Media Encoder, Compressor, HandBrake, or Shutter Encoder.  It may be worth trying a high-end solution like Telestream Vantage Transcode.

Getting back to intended use, for YouTube, I would aim to upload the highest quality video supported by the platform for the best possible results with the encoding that's going to happen on the YouTube side.  Currently, that is ProRes 422 HQ that for 1080p25 ProRes will be about 1.3 GB per minute.  If balancing high picture quality with more manageable file sizes, I'd opt for ProRes 422 LT which at 1080p25 is about 0.7 GB per minute.  If those files sizes are still too large for local storage or internet bandwidth for uploading to YouTube, I'd stick with 1080p25 H264 at around 10 Mbps.  Even if I could get an hour of video down to 150 Mb, if the intended use it uploading it to YouTube where it's going to go through another compression pass then I would not do it.

[Billy Ramone]

Thanks again, Warren.  I produce for a variety of platforms and purposes and I've been basically using YouTube as a compression engine.  I've been uploading 2-6Gb files and downloading them at 100-500Mb. with barely any perceptble loss in quality.  It'd be awesome if Adobe Media Encoder could match those results so I could skip that step, but I can keep this up if necessary.  Fortunately, a 60+ minute video is an outlier for my shop (our vids usually run less than 5 minutes), so the file sizes aren't quite as mammoth.

Thanks again for the advice!

[Warren Heaton · Accepted solution]

For a 01:08:00:00 (1 hour, 8 minutes) 1080p 29.97 sequence, I tested exporting with the format set to H.264 and the preset set to "Match Source – Adaptive High Bitrate."

I adjusted the Video Bitrate Encoding from 1-pass (Target Bitrate: 10 Mbps, Maximum Bitrate: 23.8 Mbps) to 2-pass (Target Bitrate: 0.19 Mbps, Maximum Bitrate: 0.33 Mbps). I also lowered the Audio Bitrate from 320 kbps to 16 kbps.

As a result, the estimated file size dropped from 9,854 MB to 261 MB. You could try a similar approach and compare the results to what you're downloading from YouTube.

[Billy Ramone]

Awesome.  I'm jammed today, but I'll definitely give that a shot as soon as I get a sec and I'll post the result.  Thanks for going above and beyond to actually run test render.  Appreciate you.

[Billy Ramone]

Also, I didn't notice H.265 as an export option last time I exported, so I looked again.  I see it now (didn't realize it was called HEVC), so I'll try that out on my next render.  Thanks again!