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• configure : check $as first before using $gas as GNU as

  5 août 2014, par Janne Grunau

  configure : check $as first before using $gas as GNU as
  llvm’s integrated assembler supports the AArch64 asm on darwin since
  
  August 2014. So check $as first before using gas-preprocessor.pl via
  
  $gas. Makes the checks specific for that the architecture specific asm
  
  needs. PPC Altivec and AArch64 needs on ’:vararg’ for macro arguments.
  
  Arm needs in addition the ’.altmacro’ directive.
  

  • [DH] configure

• Xcode cannot find symbol for particular source

  19 novembre 2014, par onemach

  I have an iOS project utilizing ffmpeg. The library is pre-built and copied to the project tree

  ffmpeg/
├── include
│   ├── libavcodec
│   ├── libavdevice
│   ├── libavfilter
│   ├── libavformat
│   ├── libavresample
│   ├── libavutil
│   ├── libpostproc
│   ├── libswresample
│   └── libswscale
└── lib
   ├── libavcodec.a
   ├── libavdevice.a
   ├── libavfilter.a
   ├── libavformat.a
   ├── libavresample.a
   ├── libavutil.a
   ├── libpostproc.a
   ├── libswresample.a
   └── libswscale.a

  .h files are omitted above for clarity.

  In the Build Setting, the Header Search Paths and Library Search Paths are added respectively.

  When compiling, Xcode complains about tens of Undefined symbols for architecture x86_64, all about ffmpeg. All the errors come from the same source file. And in another source file, no error is given though it also utilize ffmpeg.

• Gstreamer pipeline to scale down video before streaming

  20 novembre 2014, par r3dsm0k3

  Here is what Im trying to achieve.

  Im streaming from a Logitech C920 camera on beaglebone black with gstreamer. I have to save a copy of the video saved locally while it is streaming. I have achieved that with tee.
  Logitech camera gives h264 encoded video at a certain bitrate, mostly very high.

  Im streaming from a moving car on 3G, and the network is not good enough to send the stream to nginx-rtmp server Im using to re-distribute thus gives strong artifacts in the result.

  Im able to alter the bitrate of captured video using uvch264.
  But then, the locally saved video also would have lower bitrate.

  Is there anyway of capturing a higher bitrate 1080p video from the camera and sending a lower resolution, lower bitrate video the streaming server ?

  Following is the pipeline I have currently.

  gst-launch-1.0 -v -e uvch264src initial-bitrate=400000 average-bitrate=400000 iframe-period=3000  device=/dev/video0 name=src auto-start=true  src.vidsrc ! queue ! video/x-h264,width=1920,height=1080,framerate=30/1 ! h264parse ! flvmux streamable=true  name=flvmuxer ! queue ! tee name=t ! queue ! filesink location=/mnt/test.flv t. ! queue ! rtmpsink location=$SERVER/hls/$CAM1

  I could also try sending the higher bitrate video to a udpsink instead of rtmpsink and with another gstreamer process parallely and takes the data using a udpsink and probably post process/ re-encode and send to rtmp server.

  Im also limited by the processing speed BeagleBone has to do for encoding the videos. Currently Im trying for 1 camera and in the finished project I would like to have 2 cameras connected. Upload speed Im getting for the network is under 1Mbps.

  How do I solve this with less load on the BeagleBone ? Im very open to a new architecture as well.