i.MX53 movie.mpg decode time

[torus1000]

Hi Chip experts,

I measured following playback time and it takes around 1 sec to display.

.mpg file --> FEC --> DDR --> VPU dec --> DDR --> IPU --> LCD

Most of time seems to spend at VPU dec.

Anyone can help me...

Why i.MX53 VPU takes so long time?

Is there any configurations to reduce startup delay such as buffer size?

Thanks.

[Yuri]

  Basically the ~1 second lag in VPU oriented pipeline is not "criminal" and
it's caused due to the sum of processing times of involved operations.

Have a great day,
Yuri

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[torus1000]

Dear Yuri,

Thank you for your reply.

Now I understand VPU decoder did pipelined processing. Please let me know 2 more things.

(Q) How many stages does decoder pipeline have?

We usually decode  MPEG-4, SimpleProfile, 15fps videos.

(Q) How many input data is enough to get 1st decoder output?

I am very appreciated for your help.

B.R.

[Yuri]

General considearions are as following :

  "The lag of ~1sec is reasonable for 15fps video with I-frame inserted every 15 frames.
The I-frame will appear about each 1 second.

To decode correct video, we always need start from I-frame, so for network playback case,

the multimedia framework will not send P-frame to VPU at first, only when there is I-frame found,

it will let VPU start to decode."

Regards,

Yuri.

[Yuri]

   Please create SR for further discussions.

Sorry, but the information you are requesting is treated as confidential info at this time

and requires a signed NDA (Non-Disclosure Agreement). Naturally, we cannot discuss this

with you in public anyway, this requires to be handled as a Service Request (SR)

Regards,

Yuri.

[Yuri]

Because of third party agreement restrictions the VPU specs are not provided, sorry.

Regards,

Yuri.