topic Re: Is userQpMin supported in i.MX6 VPU API ? in i.MX Processors

Is userQpMin supported in i.MX6 VPU API ?

masa-i — Fri, 06 May 2016 22:32:12 GMT

I'm checking several parameters in VPU API of i.MX6.
I've tried to check userQPMax/userQpMin parameter which is included in EncOpenParam.
userQpMin is not valid in Linux VPU driver. (userQpMax valid)
Does anyone know the reason?

Where can I get the latest Linux VPU driver and firmware?
(I think VPU API Reference Manual should be updated,if some parameters/functions are not supported now.)

[Current My Environment]
- Target       : i.MX6Q (SABRE-SDP)
- OS           : Linux 3.14.28
- Encoding     : H.264 (1920x1080)
- VPU firmware : Ver 3.1.1_r46063
- VPU library : Ver 5.4.28
- Ref. i.MX 6Dual/6Quad VPU Application Programming Interface Linux Reference Manual
(Rev L3.0.35_4.1.0, 09/2013)

Re: Is userQpMin supported in i.MX6 VPU API ?

Yuri — Wed, 11 May 2016 07:16:11 GMT

Hello,

You may try the recent Linux BSP L4.1.15_1.1.0-ga.

i.MX 6 Series Software and Development Tool|NXP

Have a great day,
Yuri

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Re: Is userQpMin supported in i.MX6 VPU API ?

masa-i — Mon, 16 May 2016 00:11:35 GMT

Hi Yuri,

Thank you for the information. I will try to check with the latest Linux BSP.

Is there any update about this matter by recent Linux BSP ?

Thanks.

Masahiro Ichkawa

Re: Is userQpMin supported in i.MX6 VPU API ?

masa-i — Tue, 17 May 2016 09:50:57 GMT

I've tried with the recent Linux BSP L4.1.15_1.1.0-ga. But nothing has been changed.

VPU firmware version: 3.1.1_r46072

VPU library version: 5.4.33

I also check source code. (vpu_lib.c)

-------------------------------------------------------------------------------------

if (cpu_is_mx6x()) {
if (pEncOP->userQpMaxEnable) {
   data |= (1 << 6);
   VpuWriteReg(CMD_ENC_SEQ_RC_QP_MIN_MAX, pEncInfo->openParam.userQpMax);
}
if (pEncOP->userGamma) {
   data |= (1 << 7);
   VpuWriteReg(CMD_ENC_SEQ_RC_GAMMA, pEncOP->userGamma);
}
} else {
if (pEncOP->userQpMinEnable) {
   data |= (1 << 6);
   VpuWriteReg(CMD_ENC_SEQ_RC_QP_MIN_MAX,
       (pEncOP->userQpMin << 8) | (pEncOP->userQpMax & 0xFF));
}
if (pEncOP->userQpMaxEnable) {
   data |= (1 << 7);
   VpuWriteReg(CMD_ENC_SEQ_RC_QP_MIN_MAX,
        (pEncOP->userQpMin << 8) | (pEncOP->userQpMax & 0xFF));
}

if (pEncOP->userGamma) {
data |= (1 << 8);
VpuWriteReg(CMD_ENC_SEQ_RC_GAMMA, pEncOP->userGamma);
}
}

-------------------------------------------------------------------------------------

It seems taht the useQPMin parameter is not supported with i.MX6 from above cord.

If there is a reason which isn't supported, I'd like to know that.

Masahiro

Re: Is userQpMin supported in i.MX6 VPU API ?

Aemj — Mon, 23 May 2016 01:39:00 GMT

Hi Yuri,

We believe that useQPMin parameter is not supported neither in your latest LinuxBSP.

Is it true?

Thanks,

Miyamoto

Re: Is userQpMin supported in i.MX6 VPU API ?

jfp — Thu, 15 Sep 2016 10:12:11 GMT

Hi everybody,

this is the only where I found someone speaking about those parameters userQPMax and userQpMin.

I have to make an application which should limit the bitrate, but not set it as constant to save bandwith and disk space. As I understand, configuring the h264 encoder with some constant bitrate and adjusting userQpMin should make the encoder works like in VBR (because of the QP min) but limiting the bitrate to a given maximum.

How can I know if the parameter userQpMin will taken in account one day ?

Is there anybody which try those parameters on an iMX7 ? Should I be sure they are taken in account and that they work correctly ?

Thanks

Jean-François