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• FFMPEG Scene Detection - Trim Blank Background from Video at the Start and End

  10 juin 2014, par user3521682

  Summary :
  Need to programatically trim video when scene is not changing at the beginning & end.

  Example video : http://www.filehosting.co.nz/finished3.mp4
  (Quality is much higher in the real video)

  Background :

  Large number of videos for online store, each video begins with a blank background, then the model walks on (at a random time, few seconds), and then walks off after a random time (around 15 seconds). The end of the video is trimmed seemingly random ; could be up to 15 seconds of ’nothing’ at the end of the video.

  The camera does not move. There is no sound on the videos.
  The videos come from a camera in MOV format, sideways.

  I already have FFMPEG converting from MOV to MP4, rotating the video, adding an audio-track, and trimming the audio at the end of the video.

  Research :
  I understand that I should probably re-encode video with a very high (?) tolerance for i-frames (so that only two are made per video) and then export the times to a text file, and use the text file to cut the video (probably parse it in BASH and use that to build the FFMPEG commands).

  Does anyone have any idea how I could generate just two key-frames per video ?

  Example video : http://www.filehosting.co.nz/finished3.mp4
  (Quality is much higher in the real video)

• Cannot play second sdp file with FFMPEG : Address already in use

  8 novembre 2017, par user1490563

  SUMMARY- iam not able to process two sdp files simultaneously on one machine. ffmpeg throws "bind failed : Address already in use"

  My aim to get an stream from webRTC ( via kurento ) and then trancode it to be sent to RTMP server. I was able to generate an dp file and it transcoded easily but second one gave an error - "Address already in use".

  What i have already tried -
  i have dynamically changed the video and audio port in both files so that ports do not overlap (files pasted at the end of question ).
  i was albe to see that while one stream was successfully getting transcoded,the other streams video and audio ports were blocked by the same FFMPEG instance running for the first one. I do not know why or how.
  Its possible that i may be doing some mistake.
  Requesting help. i will like to stream multiple live videos at the same time.

  first SDP file

  v=0
  
  o=- 0 0 IN IP4 127.0.0.1
  
  s=KMS
  
  c=IN IP4 127.0.0.1
  
  t=0 0
  
  m=audio 49170 RTP/AVP 97
  
  a=recvonly
  
  a=rtpmap:97 PCMU/8000
  
  a=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1508
  
  m=video 55000 RTP/AVP 96
  
  a=rtpmap:96 H264/90000
  
  a=fmtp:96 packetization-mode=1

  second SDP file :

  v=0
  
  o=- 0 0 IN IP4 127.0.0.1
  
  s=KMS
  
  c=IN IP4 127.0.0.1
  
  t=0 0
  
  m=audio 49171 RTP/AVP 97
  
  a=recvonly
  
  a=rtpmap:97 PCMU/8000
  
  a=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1508
  
  m=video 55001 RTP/AVP 96
  
  a=rtpmap:96 H264/90000
  
  a=fmtp:96 packetization-mode=1

• javacpp-presets ffmpeg : Trying to access Ebur128Context->integrated_loudness but unsuccessful

  11 avril 2019, par Sourabh Jain

  [FFMPEG] Trying to access Ebur128Context->integrated_loudness but unsuccessful , using javacpp presets

  I am trying to run ebur128Filter on audio file . similar to be doing
  [http://ffmpeg.org/doxygen/2.6/f__ebur128_8c_source.html#l00135]

  ffmpeg -i sample.wav -filter_complex ebur128=peak=true -f null -

  result of which is :

  [Parsed_ebur128_0 @ 0x7f9d38403ec0] Summary:
  
  
  
  Integrated loudness:
  
  I: -15.5 LUFS
  
  Threshold: -25.6 LUFS
  
  
  
  Loudness range:
  
  LRA: 1.5 LU
  
  Threshold: -35.5 LUFS
  
  LRA low: -16.3 LUFS
  
  LRA high: -14.8 LUFS
  
  
  
  True peak:
  
  Peak: -0.4 dBFS 

  package org.bytedeco.javacv;
  
  
  
  import org.bytedeco.javacpp.BytePointer;
  
  import org.bytedeco.javacpp.Pointer;
  
  import org.bytedeco.javacpp.avfilter;
  
  import org.junit.jupiter.api.Test;
  
  
  
  import java.io.InputStream;
  
  import java.nio.ByteBuffer;
  
  import java.util.logging.Level;
  
  import java.util.logging.Logger;
  
  
  
  import static org.bytedeco.javacpp.avutil.av_opt_get;
  
  
  
  public class LoudnessAndTruePeakTest {
  
  
  
      @Test
  
      public void ebur1228FilterTest() throws FrameFilter.Exception, FrameGrabber.Exception {
  
          Logger.getGlobal().setLevel(Level.ALL);
  
          String filter = "ebur128=peak=true:framelog=verbose";
  
          FFmpegFrameFilter fFmpegFrameFilter = new FFmpegFrameFilter(filter, 2);
  
          InputStream is = getClass().getResourceAsStream("/resources/sample.wav");
  
          FFmpegFrameGrabber fFmpegFrameGrabber = new FFmpegFrameGrabber(is);
  
          fFmpegFrameFilter.start();
  
          fFmpegFrameGrabber.start();
  
          Frame frame;
  
          while ((frame = fFmpegFrameGrabber.grabSamples()) != null) {
  
              fFmpegFrameFilter.push(frame);
  
  
  
  
  
          }
  
              printFilterState(fFmpegFrameFilter);
  
  
  
  
  
          fFmpegFrameGrabber.stop();
  
          fFmpegFrameFilter.stop();
  
  
  
      }
  
  
  
      private void printFilterState(FFmpegFrameFilter fFmpegFrameFilter) {
  
          avfilter.AVFilterContext filters = fFmpegFrameFilter.afilter_graph.filters(3);
  
          Pointer value = filters.priv();
  
          String name = filters.name().getString();
  
          System.out.println(name);
  
          Pointer pointer = new BytePointer(8);
  
          ByteBuffer buffer = pointer.asByteBuffer();
  
  
  
          av_opt_get(value, "integrated_loudness", 0, buffer);
  
          double db = buffer.getDouble();
  
          System.out.println("integrated_loudness : " + db);
  
  
  
          pointer = new BytePointer(8);
  
          buffer = pointer.asByteBuffer();
  
          av_opt_get(value, "i400.rel_threshold", 0, buffer);
  
          db = buffer.getDouble();
  
          System.out.println("i400.rel_threshold :" + db);
  
  
  
          pointer = new BytePointer(8);
  
          buffer = pointer.asByteBuffer();
  
          av_opt_get(value, "loudness_range", 0, buffer);
  
          db = buffer.getDouble();
  
          System.out.println("loudness_range :" + db);
  
  
  
          pointer = new BytePointer(8);
  
          buffer = pointer.asByteBuffer();
  
          av_opt_get(value, "i3000.rel_threshold :", 0, buffer);
  
          db = buffer.getDouble();
  
          System.out.println("i3000.rel_threshold :" + db);
  
  
  
          pointer = new BytePointer(8);
  
          buffer = pointer.asByteBuffer();
  
          av_opt_get(value, "lra_low", 0, buffer);
  
          db = buffer.getDouble();
  
          System.out.println("lra_low :" + db);
  
  
  
          pointer = new BytePointer(8);
  
          buffer = pointer.asByteBuffer();
  
          av_opt_get(value, "lra_high", 0, buffer);
  
          db = buffer.getDouble();
  
          System.out.println("lra_high :" + db);
  
      }
  
  }

  Output from program is :
  
  
  
  Input #0, wav, from 'java.io.BufferedInputStream@2a40cd94':
  
  Metadata:
  
  title : test
  
  album : test
  
  artist : test
  
  genre : Cinematic
  
  Duration: N/A, bitrate: 256 kb/s
  
  Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 8000 Hz, 2 channels, s16, 256 kb/s
  
  Invalid return value 0 for stream protocol
  
  Invalid return value 0 for stream protocol
  
  Parsed_ebur128_0
  
  integrated_loudness : 2.315841784746324E77
  
  i400.rel_threshold :2.315841784746324E77
  
  loudness_range :2.315841784746324E77
  
  i3000.rel_threshold :1.3561678660795056E248
  
  lra_low :2.315841784746324E77
  
  lra_high :2.0858062529025373E-306
  
  [Parsed_ebur128_0 @ 0x7f8942683940] Summary:
  
  
  
  Integrated loudness:
  
  I: -70.0 LUFS
  
  Threshold: 0.0 LUFS
  
  
  
  Loudness range:
  
  LRA: 0.0 LU
  
  Threshold: 0.0 LUFS
  
  LRA low: 0.0 LUFS
  
  LRA high: 0.0 LUFS
  
  
  
  True peak:
  
  Peak: -inf dBFS
  
  
  
  Process finished with exit code 0

  not sure what I am doing wrong here