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• Can you "stream" images to ffmpeg to construct a video, instead of saving them to disk ?

  8 juillet 2016, par Brandon

  My work recently involves programmatically making videos. In python, the typical workflow looks something like this :

  import subprocess, Image, ImageDraw
  
  
  
  for i in range(frames_per_second * video_duration_seconds):
  
      img = createFrame(i)
  
      img.save("%07d.png" % i)
  
  
  
  subprocess.call(["ffmpeg","-y","-r",str(frames_per_second),"-i", "%07d.png","-vcodec","mpeg4", "-qscale","5", "-r", str(frames_per_second), "video.avi"])

  This workflow creates an image for each frame in the video and saves it to disk. After all images have been saved, ffmpeg is called to construct a video from all of the images.

  Saving the images to disk (not the creation of the images in memory) consumes the majority of the cycles here, and does not appear to be necessary. Is there some way to perform the same function, but without saving the images to disk ? So, ffmpeg would be called and the images would be constructed and fed to ffmpeg immediately after being constructed.

• I wonder why logcat says "NO SUCH A FILE OR DIRECTORY(2)"

  22 septembre 2013, par autoexebat

  I wanna play audio on Android with ffmpeg.
  But when I run this project, error has occurred

  what should I do ?

  java SIDE

  import java.io.FileNotFoundException;
  
  import java.io.FileOutputStream;
  
  import java.io.IOException;
  
  import android.app.Activity;
  
  import android.media.AudioFormat;
  
  import android.media.AudioManager;
  
  import android.media.AudioTrack;
  
  import android.media.MediaPlayer;
  
  import android.os.Bundle;
  
  import android.os.SystemClock;
  
  
  
  public class FFmpegBasic extends Activity
  
  {
  
      private AudioTrack track;
  
      private FileOutputStream os;
  
      /** Called when the activity is first created. */
  
      @Override
  
      public void onCreate(Bundle savedInstanceState)
  
      {
  
          super.onCreate(savedInstanceState);
  
          setContentView(R.layout.main);
  
          createEngine();
  
  
  
          int bufSize = AudioTrack.getMinBufferSize(44100,
  
                                                    AudioFormat.CHANNEL_CONFIGURATION_STEREO, 
  
                                                    AudioFormat.ENCODING_PCM_16BIT);
  
  
  
  
  
          track = new AudioTrack(AudioManager.STREAM_MUSIC, 
  
                                 44100, 
  
                                 AudioFormat.CHANNEL_CONFIGURATION_STEREO, 
  
                                 AudioFormat.ENCODING_PCM_16BIT, 
  
                                 bufSize,
  
                                 AudioTrack.MODE_STREAM);
  
  
  
          byte[] bytes = new byte[bufSize];
  
  
  
          try {
  
              os = new FileOutputStream("/sdcard/a.out",false);
  
          } catch (FileNotFoundException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          }
  
  
  
          String result = "/mnt/sdcard/Wildlife.mp3";
  
          loadFile(result,bytes);
  
  
  
          try {
  
              os.close();
  
          } catch (IOException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          }
  
      }
  
  
  
      void playSound(byte[] buf, int size) {  
  
          if(track.getPlayState()!=AudioTrack.PLAYSTATE_PLAYING)
  
              track.play();
  
          track.write(buf, 0, size);
  
  
  
          try {
  
              os.write(buf,0,size);
  
          } catch (IOException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          }
  
      }
  
  
  
  
  
      private native void createEngine();
  
      private native void loadFile(String file, byte[] array);
  
  
  
      /** Load jni .so on initialization*/ 
  
      static {
  
           System.loadLibrary("avutil"); 
  
           System.loadLibrary("avcore"); 
  
           System.loadLibrary("avcodec");
  
           System.loadLibrary("avformat");
  
           System.loadLibrary("avdevice");
  
           System.loadLibrary("swscale");
  
           System.loadLibrary("avfilter");
  
           System.loadLibrary("ffmpeg");
  
           System.loadLibrary("basicplayer");
  
      }
  
  }

  ---

  c SIDE

  ---

  #include 
  
  #include 
  
  #include 
  
  #include <android></android>log.h>
  
  
  
  #include "libavcodec/avcodec.h"
  
  #include "libavformat/avformat.h"
  
  #include "avcodec.h"
  
  #include "avformat.h"
  
  
  
  
  
  
  
  
  
  void Java_net_jbong_FFmpegBasic_FFmpegBasic_createEngine(JNIEnv* env, jclass clazz)
  
      {
  
          //avcodec_init();
  
  
  
          av_register_all();
  
  
  
  
  
      }
  
  
  
  void Java_net_jbong_FFmpegBasic_FFmpegBasic_loadFile(JNIEnv* env, jobject obj, jstring file, jbyteArray array)
  
  {
  
  
  
      AVFormatContext *gFormatCtx = NULL;
  
      AVCodecContext *gAudioCodecCtx = NULL;
  
      AVCodec *gAudioCodec = NULL;
  
      int gAudioStreamIdx = -1;
  
      char *gAudioBuffer = NULL;
  
      int i, outsize = 0;
  
      AVPacket packet;
  
      const char *str; 
  
      str = (*env)->GetStringUTFChars(env, file, NULL); 
  
      jclass cls = (*env)->GetObjectClass(env, obj); 
  
      jmethodID play = (*env)->GetMethodID(env, cls, "playSound", "([BI)V"); 
  
  
  
      if (gFormatCtx != NULL)
  
          return -1;
  
      if (av_open_input_file(&amp;gFormatCtx,str,NULL,0,NULL)!=0)
  
          return -2;
  
      if (av_find_stream_info(gFormatCtx) &lt; 0)
  
          return -3;
  
  
  
      for(i=0; inb_streams; i++)
  
      {
  
          if(gFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
  
          {
  
              gAudioStreamIdx = i;
  
              break;
  
          }
  
      }
  
  
  
      if (gAudioStreamIdx == -1)
  
          return -4;
  
      gAudioCodecCtx = gFormatCtx->streams[gAudioStreamIdx]->codec;
  
      gAudioCodec = avcodec_find_decoder(gAudioCodecCtx->codec_id);
  
  
  
      if (gAudioCodec == NULL)
  
          return -5;
  
  
  
      if (avcodec_open(gAudioCodecCtx, gAudioCodec)&lt;0)
  
          return -6;
  
  
  
  
  
      gAudioBuffer = (char *)av_malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE *2); 
  
      int decode = 0;
  
  
  
      while (av_read_frame(gFormatCtx, &amp;packet) >= 0)
  
      {
  
       if (gFormatCtx-> streams[packet.stream_index]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
  
       {
  
           int data_size = AVCODEC_MAX_AUDIO_FRAME_SIZE * 8; 
  
           gAudioBuffer = (char *)av_malloc(data_size);
  
           int size=packet.size;
  
           while(size > 0)
  
           {
  
            int len = avcodec_decode_audio3(gAudioCodecCtx,
  
              (short *) gAudioBuffer, &amp;data_size, &amp;packet);
  
            if (data_size > 0)
  
            {
  
                      jbyte *bytes = (*env)->GetByteArrayElements(env, array, NULL);
  
                         memcpy(bytes + decode, (int16_t *)gAudioBuffer, size);
  
                         (*env)->ReleaseByteArrayElements(env, array, bytes, 0);
  
                         (*env)->CallVoidMethod(env, obj, play, array, data_size); 
  
                         decode += size;
  
                         size -= len;
  
  
  
            }
  
           }
  
       }
  
       av_free_packet(&amp;packet);
  
      }
  
  
  
      av_close_input_file(gFormatCtx);
  
      return 0;
  
  }

  Why my android logcat show me this message ?
  "error opening trace file : No such file or directory (2)"

• Trying to compile x264 and ffmpeg for iPhone - "missing required architecture arm in file"

  11 février 2013, par jtrim

  I'm trying to compile x264 for use in an iPhone application. I see there are instructions on how to compile ffmpeg for use on the platform here : http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2009-October/076618.html , but I can't seem to find anything this complete for compiling x264 on the iPhone. I've found this source tree : http://gitorious.org/x264-arm that seems to have support for the ARM platform.

  Here is my config line :

  ./configure —cross-prefix=/usr/bin/ —host=arm-apple-darwin10 —extra-cflags="-B /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.2.sdk/usr/lib/ -I /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.2.sdk/usr/lib/"
  

  ...and inside configure I'm using the gas-preprocessor script (first link above) as my assembler :

  gas-preprocessor.pl gcc
  

  When I start compiling, it chunks away for a little while, then it spits out these warnings and a huge list of undefined symbols :

  ld : warning : option -s is obsolete and being ignored
  ld : warning : -force_cpusubtype_ALL will become unsupported for ARM architectures
  ld : warning : in /usr/lib/crt1.o, missing required architecture arm in file
  ld : warning : in /usr/X11R6/lib/libX11.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libm.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libpthread.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libgcc_s.1.dylib, missing required architecture arm in file
  ld : warning : in /usr/lib/libSystem.dylib, missing required architecture arm in file
  Undefined symbols :
  

  My guess would be that the problem has to do with the "missing required architecture arm in file" warning...any ideas ?