Recherche avancée

Sur d’autres sites (8388)

• Random Fatal signal 11 (SIGSEGV) error in app using ffmpeg through ndk

  20 janvier 2015, par grzebyk

  I am getting a nasty but well known error while working with FFmpeg and NDK :

  A/libc(9845): Fatal signal 11 (SIGSEGV), code 1, fault addr 0xa0a9f000 in tid 9921 (AsyncTask #4)

  What am I doing ?

  I am developing an application that streams live video feed from a webcam and enables user to pan and tilt the remote camera. I am using FFmpeg library built with NDK to achieve smooth playback with little delay.

  I am using FFMpeg library to connect to the video stream. Then the ndk part creates bitmap, does the image processing and render frames on the SurfaceView videoSurfaceView object which is located in the android activity (java part).

  To move the webcam I created a separate class - public class CameraMover implements Runnable{/**/}. This class is a separate thread that connects through sockets with the remote camera and manages tasks connected ONLY with pan-tilt movement.

  Next in the main activity i created a touch listener

  videoSurfaceView.setOnTouchListener(new View.OnTouchListener() {/**/
  
  cameraMover.setPanTilt(some parameters);
  
  /**/}

  which reads user’s finger movement and sends commands to the camera.

  All tasks - moving camera around, touch interface and video playback are working perfectly when the one of the others is disabled, i.e. when I disable possibility to move camera, I can watch video streaming and register touch events till the end of time (or battery at least). The problem occurs only when task are configured to work simultaneously.

  I am unable to find steps to reproduce the problem. It just happens, but only after user touches the screen to move camera. It can be 15 seconds after first interaction, but sometimes it takes app 10 or more minutes to crash. Usually it is something around a minute.

  What have I done ?

  • I tried to display millions of logs in logcat to find an error but
    the last log was always different.
  • I created a transparent surface, that I put over the videoSurfaceView and assigned touch listener to it. It all ended in the same error.
  • As I mentioned before, I turned off some functionalities to find which one produces the error, but it appears that error occurs only when everything is working simultaneously.

  Types of the error

  Almost every time the error looks like this :

  A/libc(11528): Fatal signal 11 (SIGSEGV), code 1, fault addr 0x9aa9f00c in tid 11637 (AsyncTask #4)

  the difference between two errors is the number right after libc, addr number and tid number. Rarely the AsyncTask number varies - i received #1 couple times but I was unable to reproduce it.

  Question

  How can i avoid this error ? What can be the source of it ?

• aarch64 : vp9 : Add NEON optimizations of VP9 MC functions

  14 novembre 2016, par Martin Storsjö

  aarch64 : vp9 : Add NEON optimizations of VP9 MC functions
  This work is sponsored by, and copyright, Google.
  These are ported from the ARM version ; it is essentially a 1:1
  
  port with no extra added features, but with some hand tuning
  
  (especially for the plain copy/avg functions). The ARM version
  
  isn’t very register starved to begin with, so there’s not much
  
  to be gained from having more spare registers here - we only
  
  avoid having to clobber callee-saved registers.
  Examples of runtimes vs the 32 bit version, on a Cortex A53 :
  
                                       ARM   AArch64
  
  vp9_avg4_neon :                      27.2      23.7
  
  vp9_avg8_neon :                      56.5      54.7
  
  vp9_avg16_neon :                    169.9     167.4
  
  vp9_avg32_neon :                    585.8     585.2
  
  vp9_avg64_neon :                   2460.3    2294.7
  
  vp9_avg_8tap_smooth_4h_neon :       132.7     125.2
  
  vp9_avg_8tap_smooth_4hv_neon :      478.8     442.0
  
  vp9_avg_8tap_smooth_4v_neon :       126.0      93.7
  
  vp9_avg_8tap_smooth_8h_neon :       241.7     234.2
  
  vp9_avg_8tap_smooth_8hv_neon :      690.9     646.5
  
  vp9_avg_8tap_smooth_8v_neon :       245.0     205.5
  
  vp9_avg_8tap_smooth_64h_neon :    11273.2   11280.1
  
  vp9_avg_8tap_smooth_64hv_neon :   22980.6   22184.1
  
  vp9_avg_8tap_smooth_64v_neon :    11549.7   10781.1
  
  vp9_put4_neon :                      18.0      17.2
  
  vp9_put8_neon :                      40.2      37.7
  
  vp9_put16_neon :                     97.4      99.5
  
  vp9_put32_neon/armv8 :              346.0     307.4
  
  vp9_put64_neon/armv8 :             1319.0    1107.5
  
  vp9_put_8tap_smooth_4h_neon :       126.7     118.2
  
  vp9_put_8tap_smooth_4hv_neon :      465.7     434.0
  
  vp9_put_8tap_smooth_4v_neon :       113.0      86.5
  
  vp9_put_8tap_smooth_8h_neon :       229.7     221.6
  
  vp9_put_8tap_smooth_8hv_neon :      658.9     621.3
  
  vp9_put_8tap_smooth_8v_neon :       215.0     187.5
  
  vp9_put_8tap_smooth_64h_neon :    10636.7   10627.8
  
  vp9_put_8tap_smooth_64hv_neon :   21076.8   21026.9
  
  vp9_put_8tap_smooth_64v_neon :     9635.0    9632.4
  These are generally about as fast as the corresponding ARM
  
  routines on the same CPU (at least on the A53), in most cases
  
  marginally faster.
  The speedup vs C code is pretty much the same as for the 32 bit
  
  case ; on the A53 it’s around 6-13x for ther larger 8tap filters.
  
  The exact speedup varies a little, since the C versions generally
  
  don’t end up exactly as slow/fast as on 32 bit.
  This is an adapted cherry-pick from libav commit
  
  383d96aa2229f644d9bd77b821ed3a309da5e9fc.
  Signed-off-by : Ronald S. Bultje <rsbultje@gmail.com>
  

  • [DH] libavcodec/aarch64/Makefile
  • [DH] libavcodec/aarch64/vp9dsp_init_aarch64.c
  • [DH] libavcodec/aarch64/vp9mc_neon.S
  • [DH] libavcodec/vp9.c
  • [DH] libavcodec/vp9dsp.c
  • [DH] libavcodec/vp9dsp.h

• avcodec_open2 error -542398533

  24 mars 2016, par bot1131357

  I am encountering an error when trying to open the codec with avcodec_open2(). I have tried the same code without any problems if I specify "avi" instead of "h264" in the av_guess_format() function.

  I have seen avcodec_open2() returning -22, but -542398533... I don’t know what to make of it. Has anyone else encountered a similar problem ?

  The library that I’m using is ffmpeg-20160219-git-98a0053-win32-dev. I would really really appreciate if you could help me out of this confusion.

  This is my console output :

  Video encoding
  
  [libx264 @ 01383460] broken ffmpeg default settings detected
  
  [libx264 @ 01383460] use an encoding preset (e.g. -vpre medium)
  
  [libx264 @ 01383460] preset usage: -vpre <speed> -vpre <profile>
  
  [libx264 @ 01383460] speed presets are listed in x264 --help
  
  [libx264 @ 01383460] profile is optional; x264 defaults to high
  
  Cannot open video codec, -542398533
  
  </profile></speed>

  This is the code that I’m working with :

  // Video encoding sample
  
  AVCodec *codec = NULL;
  
  AVCodecContext *codecCtx= NULL;
  
  AVFormatContext *pFormatCtx = NULL;
  
  AVOutputFormat *pOutFormat = NULL;
  
  AVStream * pVideoStream = NULL;;
  
  AVFrame *picture = NULL;;
  
  
  
  int i, x, y, ret;
  
  
  
  printf("Video encoding\n");
  
  
  
  // Register all formats and codecs
  
  av_register_all();
  
  
  
  // guess format from file extension
  
  pOutFormat = av_guess_format("h264", NULL, NULL);
  
  if (NULL==pOutFormat){
  
      cerr << "Could not guess output format" << endl;
  
      return -1;
  
  }   
  
  
  
  // allocate context
  
  pFormatCtx = avformat_alloc_context();
  
  pFormatCtx->oformat = pOutFormat;
  
  memcpy(pFormatCtx->filename,filename,
  
      min(strlen(filename), sizeof(pFormatCtx->filename)));
  
  
  
  // Add stream to pFormatCtx
  
  pVideoStream = avformat_new_stream(pFormatCtx, 0);
  
  if (!pVideoStream) 
  
  {
  
      printf("Cannot add new video stream\n");
  
      return -1;
  
  }
  
  
  
  // Set stream's codec context
  
  codecCtx = pVideoStream->codec;
  
  codecCtx->codec_id = (AVCodecID)pOutFormat->video_codec;
  
  codecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
  
  codecCtx->frame_number = 0;
  
  // Put sample parameters.
  
  codecCtx->bit_rate = 2000000;
  
  // Resolution must be a multiple of two.
  
  codecCtx->width  = 320;
  
  codecCtx->height = 240;
  
  codecCtx->time_base.den = 10;
  
  codecCtx->time_base.num = 1;
  
  pVideoStream->time_base.den = 10;
  
  pVideoStream->time_base.num = 1;
  
  codecCtx->gop_size = 12; // emit one intra frame every twelve frames at most
  
  codecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
  
  
  
  if (codecCtx->codec_id == AV_CODEC_ID_H264)
  
  {
  
      // Just for testing, we also add B frames 
  
      codecCtx->mb_decision = 2;
  
  }
  
  // Some formats want stream headers to be separate.
  
  if(pFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
  
  {
  
      codecCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
  }
  
  
  
  if(codecCtx->codec_id == AV_CODEC_ID_H264)
  
      av_opt_set(codecCtx->priv_data, "preset", "slow", 0);
  
  
  
  
  
  // Open the codec.
  
  codec = avcodec_find_encoder(codecCtx->codec_id);
  
  if (codec == NULL) {
  
      fprintf(stderr, "Codec not found\n");
  
      return -1;
  
  }
  
  ret = avcodec_open2(codecCtx, codec, NULL); // returns -542398533 here
  
  if (ret < 0) 
  
  {
  
      printf("Cannot open video codec, %d\n",ret);
  
      return -1;
  
  }