topic Re: Decode JPEG in C code using VPU in i.MX Processors

Decode JPEG in C code using VPU

timf — Wed, 04 Sep 2013 08:54:43 GMT

Hi All,

Just wondering can I decode single JPEG with VPU in C code? Is there any reference to start with?

Our application need to decode a lot of JPEG every second. I know iMX6 it only support MJPEG stream. But I think I can pack JPEG to MJPEG first on the fly. Can anyone point me a right way to do it? Thanks.

Also, please confirm that does i.MX6 only support baseline DCT or not?

Thanks,

Tim

Re: Decode JPEG in C code using VPU

LeonardoSandova — Wed, 04 Sep 2013 15:16:59 GMT

" But I think I can pack JPEG to MJPEG first on the fly"

If you can do that, then I suggest GStreamer, using either gst-launch or a specific app with following elements

filesrc -> vpudec -> multifilesink.

Leo

Re: Decode JPEG in C code using VPU

timf — Thu, 05 Sep 2013 03:30:47 GMT

Thanks for the prompt reply.

If I have to run the app in multiple instance, does vpudec support decoding simultaneously?

Re: Decode JPEG in C code using VPU

LeonardoSandova — Thu, 05 Sep 2013 15:22:42 GMT

There is a limit of concurrent instances, but I do not know the exact number.

Re: Decode JPEG in C code using VPU

Tarek — Fri, 06 Sep 2013 06:35:53 GMT

I don't think the vpudec is your limiting factor. The limiting factor is the sink you will use for display.

Re: Decode JPEG in C code using VPU

LeonardoSandova — Tue, 10 Sep 2013 20:03:07 GMT

You are right Tarek, in this case VPU is not the limiting factor. Tim is using multisink, so seems that your limiting factor is your storage device :smileyhappy:

Leo