[FFmpeg-user] How do I determine quantization of an mp4 file?

[David Niklas]

On Thu, 29 Apr 2021 09:21:52 +0200
Tobias Rapp <t.rapp at noa-archive.com> wrote:
> On 27.04.2021 20:38, David Niklas wrote:
> > Hello,
> > If I ffprobe an mp4 file I can see things like its bitrate and its
> > resolution. But, I can't find what the quantization of the video is.
> >
> > How can I determine that?
>
> You can take a look at the pixel format (pix_fmt) value of the video
> stream. To map the pixel format into bits-per-pixel use the table
> printed by "ffprobe -pix_fmts". Or for more information about the pixel
> formats including the bit-depth per components use "ffprobe
> -show_pixel_formats -print_format json".
>
> Regards,
> Tobias
>

I have a rudimentary idea of what I need to do to get the value. Here are
the relevant details:

yuv420p
1074kb/s
1920x1080
29.97fps
00:22:09.20

FLAGS NAME            NB_COMPONENTS BITS_PER_PIXEL
IO... yuv420p                3            12

But when I try to come up with a useful value from that data I get a very
large value. Much higher than the typical 24-60 or so for quantization
that I see in files I encode.

Have I gotten the formula correct?

Size WxH  BPP FPS    Duration       Bitrate
(1920*1080*12*29.97*((22*60)+09.2))/1074000

Thanks,
David