Regarding next EZSDK 5.03 and Gstreamer lib

Hi prashant,

I guess you might had worked on the v4l2 for capture.

I am struggling a lot to capture video from web cam (Logitech C170) and audio from mic and save the output into an avi container.

If you were successful with your video recording, can you please help me out.

Thanks in advance

Baz

Hello Baz,

Could you provide more details, please.

What is the software release that you are using here?

For capturing are you using gstreamer?

What is your video source and how is connected?

BR

Margarita

Hi Margarita,

I am really glad for your help.

Well, my aim is to capture the video and audio and save them into a AVI container.

I am using Ubuntu 10.04 and Linux 2.6.32-38-generic on i686 GNU/Linux and logitech C170 webcam.

My Target is to write a C code with two threads, one for Video capturing and other for audio capturing(Synchronization may not be perfect).  I was able to capture audio coming from the mic, using GStreamer api's. I don't know how to capture the video and place both audio and video into a single file. I have been restricted in using any command line tools like Mplayers, ffmpeg...

I am trying to use the gst_element_factory_make in order to set the video caputre settings. But unfortunately, I see an error when I run the program. I read an error saying " One element could not be created. Exiting "

   encoder = gst_element_factory_make ("ffenc_mpeg4","mpeg-decoder");

This specific line give me that error.

The video recording code has been attached. Please help me..!!

Hello,

basavaraju Gandla said:

   encoder = gst_element_factory_make ("ffenc_mpeg4","mpeg-decoder");

   source = gst_element_factory_make ("v4l2src", "file-source");
 
   vrate = gst_element_factory_make ("videorate", "video-rate");
 
   filter = gst_element_factory_make ("capsfilter", "filter");
 
   conv = gst_element_factory_make ("ffmpegcolorspace","converter");
 
   encoder = gst_element_factory_make ("ffenc_mpeg4","mpeg-decoder");
 
   sink = gst_element_factory_make ("udpsink","audio-output");

Probably you are seeing the error because some of the previous elements are not correct. Please check what are the caps which you are passed. Also if you wish to be sure that is correct just execute the pipeline without your program.

gst-launch v4l2src ..... ! .....

Best Regards,

Margarita

Hello,

Also I would recommend to you to use omx_mpeg4enc not ffenc_mpeg4. The ffdec_enc it is implemented in the gstreamer plugin, so it doesn't use hardware acceleration. Same is for ffmpegcolorspace element. The uses of ffmpegcolorspace could leads to ARM load at least this element does colour conversion.

gst-launch v4l2src ..... ! caps ! omx_mpeg4enc ! qtmux ! filesink/udpsink

BR

Margarita

Margarita,

As you recommended, I was using this line for test :-

gst-launch v4l2src ! 'video/x-raw-yuv,width=640,height=480'! ffmpegcolorspace ! ximagesink

This gives me access to webcam, I was able to open the webcam.

When I tried to use this command, A warring appears.

gst-launch v4l2src num-buffers=1000 ! video/x-raw-yuv,format=\(fourcc\)NV12,width=640,height=480,framerate=\(fraction\)60/1 ! omx_mpeg4enc ! video/mpeg,mpegversion=4,systemstream=false ! gstperf ! filesink location=sample.mpeg4

WARNING: erroneous pipeline: no element "omx_mpeg4enc"

Can you help me how to get rid of this warning.

Thanks in advance

Baz

Hello,

basavaraju Gandla said:

gst-launch v4l2src num-buffers=1000 ! video/x-raw-yuv,format=\(fourcc\)NV12,width=640,height=480,framerate=\(fraction\)60/1 ! omx_mpeg4enc ! video/mpeg,mpegversion=4,systemstream=false ! gstperf ! filesink location=sample.mpeg4

Are you executing this on the board or you are trying to execute it on the PC?

BR

Margarita

Baz,

What is your use case?

Is it:

PC side:

capture->encoding->streaming

dm8168 side:

decoding->display

or

reverse?

BR

Margarita

Margarita,

Its PC side:-

capture->encoding->streaming-> save to avi container.

BR,

Baz

Hello,

then the previous pipeline won't work. You should use ffenc_mpeg4.

Are you will decode on the dm8168?

What is the EZSDK version that you are using also?

BR

Margarita

Hi,

As of now I am not working on board.

I have been asked to write a C application using which we can capture the audio and video.

Later stages, this application will be made to run on DM8148 board.

BR,

Baz

Margarita,

I tried to use ffenc_mpeg4, But it saying " One element could not be created. Exiting" .

I dont Know how to solve this.

BR

Baz

Hello,

It would be nice to read, what is supported in omx-gstreamer for dm8148.

I do not see in your code nothing about the pads.

Please refer to http://gstreamer.freedesktop.org/, there is a documentation regarding gstreamer including example how to build our own application(http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/chapter-helloworld.html).

Let me know is this working for you.

BR

Margarita

Hello,

basavaraju Gandla said:

I tried to use ffenc_mpeg4, But it saying " One element could not be created. Exiting" .

encoder = gst_element_factory_make ("ffenc_mpeg4","mpeg-decoder");

Encoder.

BR

Margarita

#include <unistd.h>
#include <string>
#include <iostream>
using namespace std ;

#include <gst/gst.h>
#include <gst/gstelementfactory.h>

int nbrec = 0 ;


GstElement *pipeline ;
GstElement *src, *tee, *queue, *sink ;
GstElement *videobin ;
GstElement *queue2, *enc, *mux, *filesink ;
GstPad *teepad ;
GstPad *gpad ;

void pad_blocked(GstPad *pad, gboolean blocked, gpointer user_data)
{
  g_printerr ( "pad blocked\n ");
}

void create_video_bin()
{
  // First record : create videobin
  g_printerr ("create video bin\n" ) ;
  videobin = gst_bin_new("videobin") ;
  gst_object_ref(videobin) ;
  
  queue2 = gst_element_factory_make("queue", NULL) ;
  gst_bin_add(GST_BIN(videobin), queue2) ;
  
  enc = gst_element_factory_make("theoraenc", NULL) ;
  g_object_set(G_OBJECT(enc), "quality", 16, NULL) ;
  gst_bin_add(GST_BIN(videobin), enc) ;
  
  mux = gst_element_factory_make("oggmux", NULL) ;      
  gst_bin_add(GST_BIN(videobin), mux) ;
  
  filesink = gst_element_factory_make("filesink", NULL) ;
  g_object_set(G_OBJECT(filesink), "async", FALSE, NULL) ;
  gst_bin_add(GST_BIN(videobin), filesink) ;
  
  // Create vide bin ghost src pad
  GstPad *pad = gst_element_get_pad(queue2, "sink") ;
  gpad = gst_ghost_pad_new("sink", pad) ;
  gst_element_add_pad(videobin, gpad) ;
  gst_object_unref(pad) ;
  
  gst_element_link_many(queue2, enc, mux, filesink, NULL) ;
  
  gst_element_set_state(videobin, GST_STATE_READY) ;
}

void start_recording()
{
  nbrec++ ;
  char fname[32] ;
  sprintf(fname, "Test_output%d.avi", nbrec) ;
  g_object_set(G_OBJECT(filesink), "location", fname, NULL) ;
  
  // Get tee pad and block
  g_printerr( "Start Recording : get tee request pad\n" ) ;
  teepad = gst_element_get_request_pad(tee, "src%d") ;

  // Add videobin
  g_printerr ("Start Recording : add videobin\n") ;
  gst_bin_add(GST_BIN(pipeline), videobin) ;
  
  // Link tee -> videobin
  g_printerr ("Start Recording : link tee -> videobin\n") ;
  gst_pad_link(teepad, gpad) ;

  // Go playing
  g_printerr("Start Recording : go to PLAYING\n" ) ;
  gst_element_set_state(videobin, GST_STATE_PLAYING) ;
    
}

void stop_recording()
{
  g_printerr ("Stop Recording : send eos\n" ) ;
  gst_element_send_event(enc, gst_event_new_eos()) ;

  g_printerr ("Stop Recording : go to NULL\n") ;
  gst_element_set_state(videobin, GST_STATE_NULL) ;

  g_printerr ("Stop Recording : unlink tee -> videobin\n") ;
  gst_pad_unlink(teepad, gpad) ;

  g_printerr ("Stop Recording : remove videobin\n");
  gst_bin_remove(GST_BIN(pipeline), videobin) ;

  g_printerr ("Stop Recording : release request tee pad\n") ;
  gst_element_release_request_pad(tee, teepad) ;
}

int main(int argc, char *argv[])
{

  gst_init(0,0) ;

  pipeline = gst_pipeline_new(NULL) ;

  g_signal_connect (pipeline, "deep_notify",G_CALLBACK (gst_object_default_deep_notify), NULL);

  src = gst_element_factory_make("v4l2src", NULL) ;
  g_object_set(G_OBJECT(src), "pattern", 0, NULL) ;
  gst_bin_add(GST_BIN(pipeline), src) ;

  GstCaps *caps = gst_caps_from_string("video/x-raw-yuv, format=(fourcc)I420,width=640,height=480") ;  
  GstElement *filter = gst_element_factory_make("capsfilter", NULL) ;
  g_object_set(G_OBJECT(filter), "caps", caps, NULL) ;
  gst_bin_add(GST_BIN(pipeline), filter) ;

  tee = gst_element_factory_make("tee", NULL) ;
  gst_bin_add(GST_BIN(pipeline), tee) ;

  queue = gst_element_factory_make("queue", NULL) ;
  gst_bin_add(GST_BIN(pipeline), queue) ;

  sink = gst_element_factory_make("xvimagesink", NULL) ;
  gst_bin_add(GST_BIN(pipeline), sink) ;

  gst_element_link_many(src, filter, tee, queue, sink, NULL) ;

  create_video_bin() ;

  gst_element_set_state(pipeline, GST_STATE_PLAYING) ;

  sleep(3) ;

  start_recording() ;

  sleep(5) ;

  stop_recording() ;

  return  0;

} ;

Hi Margarita,

For last few days I was studying on Gstreamer API's to capture Video in PC.

I came up with a C code that was able to record the video in AVI container.

I am not sure if this code, when executes on DM8148 board will do the same recording.

I have been suggested to use Openmax for the codec changes but, I don't how to use Openmax.

  Can you please help me with some example codes for using Openmax.

I have attached the video capturing code. please check it.

BR,

BAZ

Hello Baz,

I would suggest you to download the EZSDK.You could check the demos there.

Here is the link, where you could download it:

http://software-dl.ti.com/dsps/dsps_public_sw/ezsdk/latest/index_FDS.html

But also you could check for information for DVRRDK & IPNC and to chose regarding your use cases.

In EZSDK  there is a OMX demos in:

ezsdk/component-sources/omx_05_02_00_48/examples

and the documentation about the demos and the OMXIL in:

ezsdk/component-sources/omx_05_02_00_48

OMX_05_02_00_48_UserGuide.pdf

But it would be better to start with:

/ti-ezsdk_dm814x-evm_5_05_02_00/docs

DM814x_EZ_Software_Developers_Guide.pdf

In component-sources folder you could find gst-openmax_GST_DM81XX_00_07_00_00 also.

We are using gstreamer plugin 0.10 with omx elements.

ezsdk/component-sources/gst-openmax_GST_DM81XX_00_07_00_00/omx

I would recommend you to use  gstomx encoder/decoders not ffmpeg. The ffmpeg it is implemented in the gstreamer plugin, so it doesn't use hardware acceleration.

You could find gstreamer example pipelines here:

http://processors.wiki.ti.com/index.php/DM81xx_Gstreamer_Pipelines

Regarding video capturing you could use OMX or v4l2. 

There is a OMX demo for capture_encode.

Regarding v4l2 you could check:

http://processors.wiki.ti.com/index.php/TI81XX_PSP_VIDEO_CAPTURE_Driver_User_Guide

There are v4l2 sample application which you could find in:

example-applications/linux-driver-examples-psp04.04.00.01/video

More information you could find in:

ezsdk/board-support/docs

Please let me know if you need further details.

BR
Margarita