<p>I converted an <strong>avc (h264)</strong> file to an <strong>hevc (h265)</strong> file and an <strong>av1</strong> file. </p>

<p>Relative to the <strong>hevc (h265)</strong> file, the <strong>av1</strong> file is far larger in size, and the <strong>av1</strong> file has worse psnr and ssim results too.</p>

<p>With the <strong>hevc (h265)</strong> file, i used the default crf setting (28)</p>

<p><strong>av1</strong> doesn't have a default crf amount, but i used the ffmpeg recommendation of 30</p>

<p>Here's the command i used to do the <strong>hevc (h265)</strong> conversion</p>

<pre><code>C:\Users\l\Desktop\6-app\ffmpeg -i y.mp4 -c:v libx265 -preset 8 -vf scale=1920:1080 -r 60 -ab 192k -ar 48k -map_chapters -1 -map_metadata -1 z.mp4
</code></pre>

<p>Here's the command i used to do the <strong>av1</strong> conversion</p>

<pre><code>C:\Users\l\Desktop\6-app\ffmpeg -i y.mp4 -c:v libaom-av1 -crf 30 -b:v 0 -strict experimental -vf scale=1920:1080 -r 60 -ab 192k -ar 48k -map_chapters -1 -map_metadata -1 z.mkv
</code></pre>

<p>Here are the psnr and ssim results of the <strong>hevc (h265)</strong> file</p>

<p><strong>ssim</strong></p>

<pre><code>Y:0.981764 (17.390662)
U:0.992258 (21.111573)
V:0.992246 (21.104816)
All:0.985260 (18.315015)
</code></pre>

<p><strong>psnr</strong></p>

<pre><code>y:41.620801
u:48.257839
v:47.699066
average:42.905441
min:38.873493
max:58.862531
</code></pre>

<p>Here are the psnr and ssim results of the <strong>av1</strong> file</p>

<p><strong>ssim</strong></p>

<pre><code>Y:0.923286 (11.151250)
U:0.991684 (20.800862)
V:0.987425 (19.004970)
All:0.945376 (12.626126)
</code></pre>

<p><strong>psnr</strong></p>

<pre><code>y:27.332443
u:44.955360
v:41.569108
average:29.034062
min:8.783696
max:59.518112
</code></pre>

<p>Here are the size results of the files</p>

<p><strong>avc</strong></p>

<pre><code>3.9 mb
</code></pre>

<p><strong>hevc (h265)</strong></p>

<pre><code>4.6 mb
</code></pre>

<p><strong>av1</strong></p>

<pre><code>9.59 mb
</code></pre>

<p>I know i'm compressing an already well-compressed file, I didn't necessarily expect a smaller file size - but i did expect av1 to outperform hevc (h265))</p>

<p>Here are the actual files</p>

<p><a href="https://www.dropbox.com/s/4xy7tsys5cswngb/combo-3-avc-original.mp4" rel="nofollow noreferrer">combo-3-avc-original.mp4</a></p>

<p><a href="https://www.dropbox.com/s/fnakxv248sz8w9w/combo-3-hevc.mp4" rel="nofollow noreferrer">combo-3-hevc.mp4</a></p>

<p><a href="https://www.dropbox.com/s/07x5ddc54jn7xzb/combo-3-av1.mkv" rel="nofollow noreferrer">combo-3-av1.mkv</a></p>

<p>Why would such poor results occur?</p>

<p><strong>edit:</strong></p>

<p>· here are the versions of the tools</p>

<pre><code>ffmpeg version N-93389-gd15117c996
[libaom-av1 @ 0000025b4839bf40] 1.0.0-1458-ge40c226a6
libavutil      56. 26.100 / 56. 26.100
libavcodec     58. 47.103 / 58. 47.103
libavformat    58. 26.101 / 58. 26.101
libavdevice    58.  6.101 / 58.  6.101
libavfilter     7. 48.100 /  7. 48.100
libswscale      5.  4.100 /  5.  4.100
libswresample   3.  4.100 /  3.  4.100
libpostproc    55.  4.100 / 55.  4.100
</code></pre>

CC BY-SA 4.0
2019-03-21T06:49:55.820Z
libaom is still an experimental encoder - performance will remain in flux for the time being. Which build are you using?
Gyan
CC BY-SA 4.0
2019-03-21T07:45:55.857Z
@gyan · i edited my post with version details at the bottom
abcjme
CC BY-SA 4.0
2019-03-21T07:48:27.573Z
libaom version?
Gyan
CC BY-SA 4.0
2019-03-21T08:27:51.433Z
@gyan ? how do i check libaom version
abcjme
CC BY-SA 4.0
2019-03-21T08:39:55.113Z
When you encode using libaom, ffmpeg log will have a line like this, `[libaom-av1 @ 0000000003990500] 1.0.0-1475-g7c64a0dca`
Gyan
CC BY-SA 4.0
2019-03-21T09:05:11.023Z
@gyan [libaom-av1 @ 0000025b4839bf40] 1.0.0-1458-ge40c226a6
abcjme
CC BY-SA 4.0
2019-03-21T09:05:58.673Z
@gyan · it looks like my version is old ? how do i update it
abcjme
CC BY-SA 4.0
2019-03-21T09:55:19.997Z
Not that old. It's from Mar 13 2019. Try asking at Doom 9.
Gyan
CC BY-SA 4.0
2019-03-21T14:00:36.700Z
@gyan · i registered on their forum · it said that i'd need to activate my account via email · i def put in my correct email · yet, i received no activation email · i checked my junk folder too · also, there's no button to re-send the activation link · and so, i'm unable to use the doom 9 forums
abcjme
CC BY-SA 4.0
2019-03-25T19:59:55.763Z
@gyan · i sent an email to error@doom9.net regarding the registration not working · i never received a response though
abcjme
CC BY-SA 4.0
2019-03-26T04:41:00.890Z
Register from another email address.
Gyan
CC BY-SA 4.0
2021-05-16T10:15:45.573Z
Latest version of ffmpeg in May 2021 and I confirm significantly worse compression efficiency of AV1 compared to H265, despite the far slower encoding time.
Silverstorm
<ffmpeg>
ffmpeg: av1 getting worse results than hevc (h265)
abcjme
# ffmpeg: av1 getting worse results than hevc (h265)

(Asked by: username_0 on 2019-03-19)

I converted an avc (h264) file to an hevc (h265) file and an av1 file. 
Relative to the hevc (h265) file, the av1 file is far larger in size, and the av1 file has worse psnr and ssim results too.
With the hevc (h265) file, i used the default crf setting (28)
av1 doesn't have a default crf amount, but i used the ffmpeg recommendation of 30
Here's the command i used to do the hevc (h265) conversion
C:\Users\l\Desktop\6-app\ffmpeg -i y.mp4 -c:v libx265 -preset 8 -vf scale=1920:1080 -r 60 -ab 192k -ar 48k -map_chapters -1 -map_metadata -1 z.mp4

Here's the command i used to do the av1 conversion
C:\Users\l\Desktop\6-app\ffmpeg -i y.mp4 -c:v libaom-av1 -crf 30 -b:v 0 -strict experimental -vf scale=1920:1080 -r 60 -ab 192k -ar 48k -map_chapters -1 -map_metadata -1 z.mkv

Here are the psnr and ssim results of the hevc (h265) file
ssim
Y:0.981764 (17.390662)
U:0.992258 (21.111573)
V:0.992246 (21.104816)
All:0.985260 (18.315015)

psnr
y:41.620801
u:48.257839
v:47.699066
average:42.905441
min:38.873493
max:58.862531

Here are the psnr and ssim results of the av1 file
ssim
Y:0.923286 (11.151250)
U:0.991684 (20.800862)
V:0.987425 (19.004970)
All:0.945376 (12.626126)

psnr
y:27.332443
u:44.955360
v:41.569108
average:29.034062
min:8.783696
max:59.518112

Here are the size results of the files
avc
3.9 mb

hevc (h265)
4.6 mb

av1
9.59 mb

I know i'm compressing an already well-compressed file, I didn't necessarily expect a smaller file size - but i did expect av1 to outperform hevc (h265))
Here are the actual files
combo-3-avc-original.mp4
combo-3-hevc.mp4
combo-3-av1.mkv
Why would such poor results occur?
edit:
· here are the versions of the tools
ffmpeg version N-93389-gd15117c996
[libaom-av1 @ 0000025b4839bf40] 1.0.0-1458-ge40c226a6
libavutil      56. 26.100 / 56. 26.100
libavcodec     58. 47.103 / 58. 47.103
libavformat    58. 26.101 / 58. 26.101
libavdevice    58.  6.101 / 58.  6.101
libavfilter     7. 48.100 /  7. 48.100
libswscale      5.  4.100 /  5.  4.100
libswresample   3.  4.100 /  3.  4.100
libpostproc    55.  4.100 / 55.  4.100

**Tags:** ffmpeg

> **Comments:**
> **username_1**: libaom is still an experimental encoder - performance will remain in flux for the time being. Which build are you using?  
> **username_0**: @gyan · i edited my post with version details at the bottom  
> **username_1**: libaom version?  
> **username_0**: @gyan ? how do i check libaom version  
> **username_1**: When you encode using libaom, ffmpeg log will have a line like this, `[libaom-av1 @ 0000000003990500] 1.0.0-1475-g7c64a0dca`  
> **username_0**: @gyan [libaom-av1 @ 0000025b4839bf40] 1.0.0-1458-ge40c226a6  
> **username_0**: @gyan · it looks like my version is old ? how do i update it  
> **username_1**: Not that old. It's from Mar 13 2019. Try asking at Doom 9.  
> **username_0**: @gyan · i registered on their forum · it said that i'd need to activate my account via email · i def put in my correct email · yet, i received no activation email · i checked my junk folder too · also, there's no button to re-send the activation link · and so, i'm unable to use the doom 9 forums  
> **username_0**: @gyan · i sent an email to error@doom9.net regarding the registration not working · i never received a response though  
> **username_1**: Register from another email address.  
> **username_2**: Latest version of ffmpeg in May 2021 and I confirm significantly worse compression efficiency of AV1 compared to H265, despite the far slower encoding time.  

---

## 0 answers

