How to test still image encoding of VP9 or AV1 ?

[Alexey Eromenko]

Hello,

It seems that still-image performance is important for video codecs.
I know that once upon a time there was a WebP format, but it supports
only VP8 codec.

So how can I encode my uncompressed bitmaps (*.bmp and .png) into VP9
or AV1 still images to evaluate their quality ?

Is it possible ?

--
-Alexey Eromenko "Technologov"

[Ronald S. Bultje]

Hi Alexey,

On Sat, Jul 23, 2016 at 6:42 PM, Alexey Eromenko <al4...@gmail.com> wrote:

Hello,

It seems that still-image performance is important for video codecs.
I know that once upon a time there was a WebP format, but it supports
only VP8 codec.

So how can I encode my uncompressed bitmaps (*.bmp and .png) into VP9
or AV1 still images to evaluate their quality ?

For vp9, I would suggest to use ffmpeg, since that supports image input.

Ronald 

[Alexey Eromenko]

And how to decode back into *.bmp or *.png using ffmpeg?

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--
-Alexey Eromenko "Technologov"

[Alexey Eromenko]

Any ideas on how-to encode still-image (like Windows Bitmap) into a
still-image of VP9 and AV1 ?

[Tomaž Vajngerl]

Hi,

On Fri, Jul 29, 2016 at 4:58 AM, Alexey Eromenko <al4...@gmail.com> wrote:
> Any ideas on how-to encode still-image (like Windows Bitmap) into a
> still-image of VP9 and AV1 ?

Use ffmpeg - encode png / bmp / jpg image to y4m 1 frame video - this
converts to yuv444p but you probably wish yuv420p
# ffmpeg -i picture.jpg -pix_fmt yuv444p source.y4m

Now you can encode (from y4m) and decode (to y4m) with most of codecs
like av1, vp9, daala,...

encode:
aomenc source.y4m --profile=1 -o encoded.webm
(for yuv444 as source you need --profile=1 but this is not needed for
yuv420 which is probably what you want to use)

decode:
aomdec encoded.webm -o decoded.y4m

Now you need to convert back to a image format - I use png as it is
compressed and lossless
ffmpeg -i decoded.y4m result.png

Regards, Tomaž

[Alexey Eromenko]

Thanks a lot, Tomaz, this works !

In fact I have written a nice python script that takes source PNG file
as input, and converts it into encoded AV1.WebM and AV1.PNG outputs.

Have a try:
https://www.dropbox.com/s/oq7vyyj9as97vj1/transcoder-av1.py?dl=0

[Sean Young]

Dear all,

Just wondering if the codec-devel mailing list is so well-suited for these more general discussions? (well, I personally don't mind, but some others might!) I think the IRC channel could better serve this purpose.

Thanks,

Sean