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• Repair mpeg files using ffmpeg

  17 août 2018, par rsdrsd

  I have a bunch of MPEG files which are somehow invalid or incorrect. I can play the files in different media players but when I upload the files and they should automatically be converted. It takes a very long time to create screenshots and it creates about 10000 screenshots instead of the 50 to be expected. The command is part of an automatic conversion app. With mp4 and other files it works great but whit MPEG it doesn’t work as expected. The creation of screenshots eats up all memory and processor power.

  For creating screenshots I have tried the following :

  ffmpeg -y -i /input/file.mpeg -f image2 -aspect 16:9 -bt 20M -vsync passthrough -vf select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)' /output/file-%05d.jpg

  this just creates 2 screenshots while I expect 50 or so. The following command :

  ffmpeg -y -i /input/file.mpeg -f image2 -vf fps=fps=1/10 -aspect 16:9 -vsync passthrough -bt 20M /output/file-%05d.jpg

  gave me errors about buffers :

      ffmpeg version N-39361-g1524b0f Copyright (c) 2000-2014 the FFmpeg developers
  
        built on Feb 26 2014 23:46:40 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  
        configuration: --prefix=/home/example/ffmpeg_build --extra-cflags=-I/home/example/ffmpeg_build/include --extra-ldflags=-L/home/example/ffmpeg_build/lib --bindir=/home/example/bin --extra-libs=-ldl --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libfreetype --enable-libspeex --enable-libtheora
  
        libavutil      52. 66.100 / 52. 66.100
  
        libavcodec     55. 52.102 / 55. 52.102
  
        libavformat    55. 33.100 / 55. 33.100
  
        libavdevice    55. 10.100 / 55. 10.100
  
        libavfilter     4.  2.100 /  4.  2.100
  
        libswscale      2.  5.101 /  2.  5.101
  
        libswresample   0. 18.100 /  0. 18.100
  
        libpostproc    52.  3.100 / 52.  3.100
  
      [mp3 @ 0x200d7c0] Header missing
  
      [mpegts @ 0x2008a60] DTS discontinuity in stream 0: packet 6 with DTS 34185, packet 7 with DTS 8589926735
  
      [mpegts @ 0x2008a60] Invalid timestamps stream=0, pts=7157, dts=8589932741, size=150851
  
      Input #0, mpegts, from '/home/example/app/uploads/21.mpeg':
  
        Duration: 00:03:14.75, start: 0.213000, bitrate: 26112 kb/s
  
        Program 1
  
  Stream #0:0[0x3e9]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 1440x1080 [SAR 4:3 DAR 16:9], max. 25000 kb/s, 29.97 fps, 60 tbr, 90k tbn, 59.94 tbc
  
  Stream #0:1[0x3ea]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 384 kb/s
  
      [swscaler @ 0x1ff9860] deprecated pixel format used, make sure you did set range correctly
  
      Output #0, image2, to '/home/example/app/uploads/21-%05d.jpg':
  
        Metadata:
  
  encoder         : Lavf55.33.100
  
  Stream #0:0: Video: mjpeg, yuvj420p, 1440x1080 [SAR 4:3 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 0.10 tbc
  
      Stream mapping:
  
        Stream #0:0 -> #0:0 (mpeg2video -> mjpeg)
  
      Press [q] to stop, [?] for help
  
      [mpegts @ 0x2008a60] Invalid timestamps stream=0, pts=7157, dts=8589932741, size=150851
  
      [output stream 0:0 @ 0x1ff2ba0] 100 buffers queued in output stream 0:0, something may be wrong.
  
      [output stream 0:0 @ 0x1ff2ba0] 1000 buffers queued in output stream 0:0, something may be wrong.

  and it creates about 10000 screenshots while I expect 50.

  Now I have read somewhere on how to repair some broken files. For this I have the following command :

  ffmpeg -y -i input.mpeg -codec:v copy -codec:a copy output.mpeg

  This, however, creates a file somewhat smaller, but if I run the same command on the output again, I would expect that it creates the same file, but the following command

  ffmpeg -y -i output.mpeg -codec:v copy -codec:a copy output2.mpeg

  returns a file which is much smaller and runs for only a few seconds while the original was about 3 minutes.

  If I run the "repair" commands for a not broken MPEG then it results in a much smaller file the first time I run the command. With ffprobe I checked what changed but the only thing that changes is MPEG-TS to MPEG-PS.

  If I run the command over an mp4 file it results in exactly the same file as expected. Does someone have a clue of what is going wrong. It is boggling me now for about two days and I really have no clue. Or does someone have a good suggestion on how to extract screenshots every 10 seconds without creating too much screenshots and eating up all memory and processor power.

• Invalid data found when processing input on ffmpeg m4s to mp4 transfer

  1er mars 2020, par keith scott

  The result of the power shell window

  I saw a post on here about converting m4s to mp4 and I have followed the steps of concatenating all the files into another m4s file that I called all.m4s and when I use the command ffmpeg -i allm4s.m4s -c copy video.mp4. I made the combined m4s file by coding an exe to add all the m4s files that have the word video in them to the m4s file. Here is the source code written in c# if you compile the code then that is the code I have used to make the m4s

  using System;
  
  using System.Collections.Generic;
  
  using System.Linq;
  
  using System.Text;
  
  using System.Threading.Tasks;
  
  using System.IO;
  
  
  
  namespace files
  
  {
  
      class Program
  
      {
  
          static void Main(string[] args)
  
          {
  
              string dir = Directory.GetCurrentDirectory();
  
              string[] info = Directory.GetFiles(dir);
  
              Console.WriteLine(dir + "\\allm4s.m4s");
  
              Console.ReadKey();
  
              foreach (string name in info)
  
              {
  
                  if (Path.GetFileName(name).Contains(".m4s") && Path.GetFileName(name).Contains("video"))
  
                  {
  
                      using (Stream srcStream = File.OpenRead(name))
  
                      {
  
                          using (Stream destStream = File.OpenWrite(dir+"\\allm4s.m4s"))
  
                          {
  
                              srcStream.CopyTo(destStream);
  
                              Console.WriteLine(destStream+name);
  
                          }
  
                      }
  
                  }
  
              }
  
              Console.ReadKey();
  
          }
  
      }
  
  }

  I think if there is to be an issue it is to do with this allm4s.m4s file as the file size is about 1.5mb even though each segment m4s is about 750kb each and there are quite a lot.If anyone has a way of adding concatenating lots of files together through a program/application that would be useful.

• Merge multiple mp4 (h264 + aac) videos into one frame without re-encoding

  1er décembre 2017, par shubhadeep banerjee

  I have four mp4 files with same length (1 minute each) , say 1.mp4, 2.mp4, 3.mp4 and 4.mp4. I want to merge these four videos into a single frame and create a mosaic of four videos ; 1.mp4 at the top-left, 2.mp4 at the top-right, 3.mp4 at the bottom-left and 4.mp4 at the bottom-right.

  I have tried the same using ffmpeg filter_complex.

  ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -i 4.mp4 -filter_complex "
  nullsrc=size=640x480 [base] ; [0:v] setpts=PTS-STARTPTS,
  scale=320x240 [upperleft] ; [1:v] setpts=PTS-STARTPTS, scale=320x240
  [upperright] ; [2:v] setpts=PTS-STARTPTS, scale=320x240 [lowerleft] ;
  [3:v] setpts=PTS-STARTPTS, scale=320x240 [lowerright] ;
  [base][upperleft] overlay=shortest=1 [tmp1] ; [tmp1][upperright]
  overlay=shortest=1:x=320 [tmp2] ; [tmp2][lowerleft]
  overlay=shortest=1:y=240 [tmp3] ; [tmp3][lowerright]
  overlay=shortest=1:x=320:y=240 " output.mp4

  But the problem is, ffmpeg re-encodes the video. The input videos already have h.264 + aac encoding, and the output video will have the same encoding. I would be running this code on a very low-power embedded Linux board which have only one core CPU. The board is taking almost 6x times of the file length to produce the output (i.e. 6 minutes in my case), and also consuming 100% of the CPU.

  Is there any other way to do this, without re-encoding ? I run the whole thing on Debian, so I can use any package you suggest.