topic Re: webcam streaming (h.264) using imx6 in i.MX Processors

webcam streaming (h.264) using imx6

alokkumar — Wed, 24 Apr 2013 14:31:39 GMT

Hi,

I am using webcam 720P from Logitech and I tried successfully mjpeg streaming on iMX6. Below are the commands if it is useful for some one.

iMX6 Server:

/usr/bin/gst-launch-0.10 v4l2src device=/dev/video2 ! 'video/x-raw-yuv,framerate=(fraction)30/1' ! ffmpegcolorspace ! vpuenc codec=12 ! multipartmux ! tcpserversink host=10.10.4.117 port=5000

#default resolution of this webcam is 1280x960

iMX6 Client:

gst-launch tcpclientsrc host=10.10.4.117 port=5000 ! queue ! jpegdec ! autovideosink

The above works fine.

I wanted to do the same with h.264 encoded stream instead of mjpeg, but I could not get to work. pipe says it is playing, but I could not decode it either by using vlc or iMX6 as client.

Any experts throw any idea on following.

1. how to do h.264 tcp streaming (instead of above it was mjpeg) ?

2. For mjpeg I could not use vpudec (actually it was very jerky with vpudec), any ideas why ?

appreciate if some experts share some pointers.

Re: webcam streaming (h.264) using imx6

LeonardoSandova — Mon, 29 Apr 2013 17:04:08 GMT

Hi Alok,

in case you need live-streaming, here is a document showing a pipeline.

GStreamer Live Streaming

The example uses another bin element (rtp). Try to adapt it to your needs and let me know the result. I believe the above link answers your question 1, but I am not sure about 2. Both has been queried internally.

Leo

Re: webcam streaming (h.264) using imx6

alokkumar — Tue, 30 Apr 2013 13:27:36 GMT

Thank you Leo, appreciate your response.

I will give a try.

Re: webcam streaming (h.264) using imx6

ChucoChe — Fri, 03 May 2013 22:49:53 GMT

Hi,

For question 2 when you play the file whit a pipeline (without media server) using the vpudec do you see the issue?

MJPEG should work on Mx6 according with the feature matrix.

I remember back in Mx5 only Baseline DCT MJPEG decoding was supported. I'm not support if that is the case with Mx6.

Is it possible for you to provide a file to test?

If you open the file with hex mode you can find the kind of MJPEG.

Hex	Marker	Marker Name	Description
0x FFC0	SOF0	Start of Frame 0	Baseline DCT
0x FFC1	SOF1	Start of Frame 1	Extended Sequential DCT
0x FFC2	SOF2	Start of Frame 2	Progressive DCT
0x FFC3	SOF3	Start of Frame 3	Lossless (sequential)

Michel

Re: webcam streaming (h.264) using imx6

karina_valencia — Thu, 09 May 2013 22:13:13 GMT

No update from customer

Re: webcam streaming (h.264) using imx6

alokkumar — Fri, 10 May 2013 14:42:58 GMT

I could not build up a vpudec pipeline which works with mjpeg files.

This file is captured using step 1) filesink.

I have file with .mjpeg extension, but I dont know how to send it to you. uploading youtube did not work.

Re: webcam streaming (h.264) using imx6

ChucoChe — Sat, 11 May 2013 19:12:14 GMT

Send it to my email b17952@freescale.com. Did you verify the generated file is Baseline DCT?

Michel