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• ProcessBuilder is not called when trying to start a process

  15 juin 2022, par xnok

  I am trying to understand more about the ffmpeg usage in JavaCV for android studio and for said task I am trying to use ProcessBuilder. I tried writting a simple program to debug the pb.start(); Although, I am not getting a response. What I did was to start a default/empty activity and pasted the following program :

  


  package com.example.myapplication;

import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;

import org.bytedeco.javacpp.Loader;

import android.os.Build;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity {
    static final int cols = 192;
    static final int rows = 108;
    static final String ffmpeg = Loader.load(org.bytedeco.ffmpeg.ffmpeg.class);
    static final String rtmp_url = "test.flv";
    static final String[] command = {ffmpeg,
            "-y",
            "-f", "rawvideo",
            "-vcodec", "rawvideo",
            "-pix_fmt", "bgr24",
            "-s", (Integer.toString(cols) + "x" + Integer.toString(rows)),
            "-r", "10",
            "-i", "pipe:",
            "-c:v", "libx264",
            "-pix_fmt", "yuv420p",
            "-preset", "ultrafast",
            "-f", "flv",
            rtmp_url};
    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        new Thread(t1).start();

    }
    private static Runnable t1 = () -> {
        Log.e("TAG", "void OnCreate called successfully!");
        ProcessBuilder pb = new ProcessBuilder(command).redirectErrorStream(true);
        pb.redirectErrorStream(true);
        try {
            Process process = pb.start();
            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
            OutputStream writer = process.getOutputStream();
            Log.e("TAG", "Something good happened here");
        } catch (IOException e) {
            e.printStackTrace();
            Log.e("TAG", "Nothing good happened here");
        }
    };


}


  


  My current problem is that I can't seem to start properly the processBuilder process via pb.start() ;

  


  I get the following logs from the logcat panel :

  


  2022-06-14 17:24:46.328 13371-13371/com.example.myapplication E/TAG: void OnCreate called successfully!
2022-06-14 17:24:46.333 13371-13371/com.example.myapplication E/TAG: Nothing good happened here


  


  I'd like to understand why is it skipping the try/catch block and not starting the process ?

  


  EDIT : I made some changes as per @g00se's suggestions and I got the following stack trace from the code above :

  


  2022-06-15 00:32:26.700 29787-29787/? E/USNET: USNET: appName: com.example.myapplication
2022-06-15 00:32:29.328 29787-29828/com.example.myapplication E/TAG: void OnCreate called successfully!
2022-06-15 00:32:29.330 29787-29828/com.example.myapplication E/AndroidRuntime: FATAL EXCEPTION: Thread-4
    Process: com.example.myapplication, PID: 29787
    java.lang.NullPointerException
        at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
        at com.example.myapplication.MainActivity.lambda$static$0(MainActivity.java:48)
        at com.example.myapplication.MainActivity$$ExternalSyntheticLambda0.run(Unknown Source:0)
        at java.lang.Thread.run(Thread.java:920)


  


• Compiling ffmpeg using MSVC while supporting d3d11va decoders

  2 octobre 2019, par Teamol

  I need to debug a problem in ffmpeg so I was forced to build all libs using MSVC so I get proper pdb files. I have succesfully compiled ffmpeg and I’m able to debug it. The only problem I have is that I cannot use d3d11va.

  I’ve tried to enable all configure modifiers I found to enable d3d11va. I use configure script like this.

  ../../../configure --toolchain=msvc --disable-programs --arch=x86_64 --enable-shared --disable-encoders --disable-muxers  --disable-demuxers --enable-demuxer=h264 --enable-demuxer=mov --disable-decoders --enable-decoder=h264 --disable-parsers --enable-parser=h264 --disable-bsfs --disable-protocols --disable-devices --disable-filters --target-os=win32 --extra-cflags="-MD -DWINAPI_FAMILY=WINAPI_FAMILY_APP -D_WIN32_WINNT=0x0A00" --extra-ldflags="-APPCONTAINER WindowsApp.lib"
  
  
  
  install prefix            ../../../Build/Windows10/x64
  
  source path               /c/Users/ffmpeg/Repositories/FFmpeg
  
  C compiler                cl.exe
  
  C library                 msvcrt
  
  ARCH                      x86 (generic)
  
  big-endian                no
  
  runtime cpu detection     yes
  
  standalone assembly       yes
  
  x86 assembler             nasm
  
  MMX enabled               yes
  
  MMXEXT enabled            yes
  
  3DNow! enabled            yes
  
  3DNow! extended enabled   yes
  
  SSE enabled               yes
  
  SSSE3 enabled             yes
  
  AESNI enabled             yes
  
  AVX enabled               yes
  
  AVX2 enabled              yes
  
  AVX-512 enabled           yes
  
  XOP enabled               yes
  
  FMA3 enabled              yes
  
  FMA4 enabled              yes
  
  i686 features enabled     yes
  
  CMOV is fast              yes
  
  EBX available             no
  
  EBP available             no
  
  debug symbols             yes
  
  strip symbols             no
  
  optimize for size         no
  
  optimizations             yes
  
  static                    no
  
  shared                    yes
  
  postprocessing support    no
  
  network support           yes
  
  threading support         w32threads
  
  safe bitstream reader     yes
  
  texi2html enabled         no
  
  perl enabled              yes
  
  pod2man enabled           yes
  
  makeinfo enabled          no
  
  makeinfo supports HTML    no
  
  
  
  External libraries:
  
  
  
  External libraries providing hardware acceleration:
  
  d3d11va
  
  
  
  Libraries:
  
  avcodec                 avdevice                avfilter                avformat                avutil                  swresample              swscale
  
  
  
  Programs:
  
  
  
  Enabled decoders:
  
  h263                    h264                    hevc                    mpeg2video              vc1                     vp9
  
  
  
  Enabled encoders:
  
  
  
  Enabled hwaccels:
  
  h264_d3d11va            hevc_d3d11va            mpeg2_d3d11va           vc1_d3d11va             vp9_d3d11va             wmv3_d3d11va
  
  h264_d3d11va2           hevc_d3d11va2           mpeg2_d3d11va2          vc1_d3d11va2            vp9_d3d11va2            wmv3_d3d11va2
  
  
  
  Enabled parsers:
  
  h263                    h264                    vp9
  
  
  
  Enabled demuxers:
  
  h264                    mov
  
  
  
  Enabled muxers:
  
  
  
  Enabled protocols:
  
  
  
  Enabled filters:
  
  
  
  Enabled bsfs:
  
  null                    vp9_superframe_split
  
  
  
  Enabled indevs:
  
  
  
  Enabled outdevs:
  
  
  
  License: LGPL version 2.1 or later
  
  libavutil/avconfig.h is unchanged
  
  libavfilter/filter_list.c is unchanged
  
  libavcodec/codec_list.c is unchanged
  
  libavcodec/parser_list.c is unchanged
  
  libavcodec/bsf_list.c is unchanged
  
  libavformat/muxer_list.c is unchanged
  
  libavdevice/indev_list.c is unchanged
  
  libavdevice/outdev_list.c is unchanged
  
  libavformat/protocol_list.c is unchanged
  
  ffbuild/config.sh is unchanged

  I would expect that this should be enough for d3d11va to work but when I call avcodec_get_hw_config (codec, i) I get empty config.

  Any idea where might be the problem ?

• FFMPEG API and cropping

  24 juin 2016, par Jguillot

  I learned how to use FFMPEG API with dranger’s tutorial, and I implemented a video reader using the library SDL to display the video.

  I have a HD video 1280*720 (i only worked with mp4) and i want to select a VGA-screen anywhere in the HD video (I mean cropping a VGA screen in a HD video), recuperate the data and display it on screen.

  In the FFMPEG API, we can use the function av_picture_crop (here). I get a "yellow" overlay on the cropped video and my application crashes after fews seconds. Before posting here, i read here that the function wasn’t finish yet. But when i reading the code, i don’t find a way to finish it.
  This is a part of my code :

  AVFrame *pFrame = NULL;
  
  AVFrame *pFrameCropped = NULL;
  
  bmp = SDL_CreateYUVOverlay(CODEC_WIDTH, // width
  
                            CODEC_HEIGHT, // height
  
                            SDL_YV12_OVERLAY, // format
  
                            screen); // SDL_Surface to display
  
  
  
  
  
  sws_ctx = sws_getContext(CODEC_WIDTH, // src width
  
                          CODEC_HEIGHT, // src height
  
                          pCodecCtx->pix_fmt, // src img format
  
                          STREAM_WIDTH, // dest width, 
  
                          STREAM_HEIGHT, // dest height
  
                          AV_PIX_FMT_YUV420P, // dest img format
  
                          SWS_BILINEAR, // option to rescalling
  
                          NULL, //
  
                          NULL, //
  
                          NULL //
  
                          );
  
  
  
  while(
  
  av_read_frame(pFormatCtx, 
  
                  &packet)>=0) 
  
  {
  
  if(packet.stream_index==videoStream) 
  
  {
  
    avcodec_decode_video2(pCodecCtx,
  
                           pFrame,
  
                           &frameFinished,
  
                           &packet);
  
  
  
    if(frameFinished) 
  
    {
  
      SDL_LockYUVOverlay(bmp);
  
  
  
      av_picture_crop((AVPicture*)pFrameCropped,
  
                       (AVPicture*)pFrame,
  
                       (AVPixelFormat)pFrame->format,
  
                       150,
  
                       300);
  
      pict.data[0] = pFrameCropped->data[0];// "X"
  
      pict.data[1] = pFrameCropped->data[1];
  
      pict.data[2] = pFrameCropped->data[2];
  
  
  
      // pict.linesize == number of bytes per line 
  
      pict.linesize[0] = pFrameCropped->linesize[0];
  
      pict.linesize[1] = pFrameCropped->linesize[2];
  
      pict.linesize[2] = pFrameCropped->linesize[1];
  
  
  
      sws_scale(sws_ctx, // the scaling context previously created with sws_getContext()
  
                  (uint8_t const * const *)pFrameCropped->data, // Pointers to the planes of the source slice 
  
                  pFrame->linesize, // the array containing the strides for each plane of the source image 
  
                  0, // position in src img processed slice.  
  
                     // It's number (counted starting from zero) 
  
                     // in the image of the first row of the slice  
  
                  CODEC_HEIGHT, // source slice height. Number of rows in the slice
  
                  pict.data, // pointers to the planes of the destination image 
  
                  pict.linesize); // strides for each plane of the destination image 
  
  
  
      // Unlock SDL_Overlay
  
      SDL_UnlockYUVOverlay(bmp);
  
  }

  Get the compilation error :

  *** glibc detected *** ./HDtoVGA: corrupted double-linked list: 0x08d74e30 ***

  In the FFMPEG command line tool, we can crop a video, using vf_crop (here) but I don’t find how to implement the same function in my code.

  Do you have any hint to help me ?