iMX53 VPU usage

[rostislav]

Hi,

I am trying to build FFMPEG v0.6.6 on an IMX53 QS board. I need this version of FFMPEG specifically, so that is why I am trying to build it from scratch. After some tests it seems that FFMPEG is not using the NEON SIMD. I would like it to do so.

The problem is, I think I am configuring it properly. My “configure” command is this:

: ./configure --enable-shared --enable-neon --enable-libx264 --enable-gpl --extra-cflags=’-mfpu=neon -mcpu=cortex-a8 -mfloat-abi=softfp’

The configure script’s summary goes on to say “NEON enabled: yes”. But I don’t think it is really engaged. Why do I think this? My kernel has MXC Debugging turned on. That means I get nice messages about the VPU usage when it is used. When I run a demo video, I see many MXC debugging prints. When I run my software which uses FFMPEG, I see no such messages. Also, performance is low and CPU usage is high.

Any ideas on how to build FFMPEG so that it REALLY engages the NEON SIMD (or VPU?)

[rostislav]

I installed the Freescale's codecs following i.MX Linux Mulimedia Framework User's Guide.

While trying to use a h264 codec we get the following error:

0:11.053 PExternalT...0x2f2be420 GStreamer mfw_gst_h264_getbuffer: >>DECODER: Error -4 in allocating the Framebuffer[0]

Could anybody point to a document that may help to interpret codec errors? What the  "Error -4" means?

[LeonardoSandova]

Hi rostislav

I wonder if you are really using the element you are building.

can you post the pipeline you are running?

are you using playbin2?

Also, I am not sure how much benefit does the '-mfpu=neon' is archive for that particular gst element. As DaianeAngolini mentioned, ffmpeg plugins do not accelerate the decoding/encoding using the VPU, so the only optimization you can get is using the NEON configure parameter, as you have done.

[rostislav]

Hi Leonardo,

Thank you for your help. Unfortunately ffmpeg is not capable to use the VPU.

I am looking for g-stream friendly solution for my application. That may use Freescale codecs.

[daiane_angolini]

That sounds good to me.

Please, keep posting your progress (here or on a new discussion). I´m sure there is somebody else working almost the same.

[daiane_angolini]

FFMPEG does not have VPU support.

As I know, any decoder from ffmpeg is sotfware based.

For the neon support, I did not understand how you concluded you´re not using it on ffmpeg, could you, please elaborate?

[rostislav]

Hi Daiane,

I mistakenly thought that Neon is a VPU name. I need to use VPU not Neon. Unfortunately ffmpeg doesn't support VPU. I actually didn't check if Neon used. To confirm VPU usage I added to each VPU related kernel API printk.