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• How to send large x264 NAL over RTMP ?

  17 septembre 2017, par samgak

  I’m trying to stream video over RTMP using x264 and rtmplib in C++ on Windows.

  So far I have managed to encode and stream a test video pattern consisting of animated multi-colored vertical lines that I generate in code. It’s possible to start and stop the stream, and start and stop the player, and it works every time. However, as soon as I modify it to send encoded camera frames instead of the test pattern, the streaming becomes very unreliable. It only starts <20% of the time, and stopping and restarting doesn’t work.

  After searching around for answers I concluded that it must be because the NAL size is too large (my test pattern is mostly flat color so it encodes to a very small size), and there is an Ethernet packet limit of around 1400 bytes that affects it. So, I tried to make x264 only output NALs under 1200 bytes, by setting i_slice_max_size in my x264 setup :

  if (x264_param_default_preset(&param, "veryfast", "zerolatency") < 0)
  
      return false;
  
  param.i_csp = X264_CSP_I420;
  
  param.i_threads = 1;
  
  param.i_width = width;  //set frame width
  
  param.i_height = height;  //set frame height
  
  param.b_cabac = 0;
  
  param.i_bframe = 0;
  
  param.b_interlaced = 0;
  
  param.rc.i_rc_method = X264_RC_ABR;
  
  param.i_level_idc = 21;
  
  param.rc.i_bitrate = 128;
  
  param.b_intra_refresh = 1;
  
  param.b_annexb = 1;
  
  param.i_keyint_max = 25;
  
  param.i_fps_num = 15;
  
  param.i_fps_den = 1;
  
  
  
  param.i_slice_max_size = 1200;
  
  
  
  if (x264_param_apply_profile(&param, "baseline") < 0)
  
      return false;

  This reduces the NAL size, but it doesn’t seem to make any difference to the reliability issues.

  I’ve also tried fragmenting the NALs, using this Java code and RFC 3984 (RTP Payload Format for H.264 Video) as a reference, but it doesn’t work at all (code below), the server says "stream has stopped" immediately after it starts. I’ve tried including and excluding the NAL header (with the timestamp etc) in each fragment or just the first, but it doesn’t work for me either way.

  I’m pretty sure my issue has to be with the NAL size and not PPS/SPS or anything like that (as in this question) or with my network connection or test server, because everything works fine with the test pattern.

  I’m sending NAL_PPS and NAL_SPS (only once), and all NAL_SLICE_IDR and NAL_SLICE packets. I’m ignoring NAL_SEI and not sending it.

  One thing that is confusing me is that the source code that I can find on the internet that does similar things to what I want doesn’t match up with what the RFC specifies. For example, RFC 3984 section 5.3 defines the NAL octet, which should have the NAL type in the lower 5 bits and the NRI in bits 5 and 6 (bit 7 is zero). The types NAL_SLICE_IDR and NAL_SLICE have values of 5 and 1 respectively, which are the ones in table 7-1 of this document (PDF) referenced by the RFC and also the ones output by x264. But the code that actually works sets the NAL octet to 39 (0x27) and 23 (0x17), for reasons unknown to me. When implementing fragmented NALs, I’ve tried both following the spec and using the values copied over from the working code, but neither works.

  Any help appreciated.

  void sendNAL(unsigned char* buf, int len)
  
  {
  
      Logging::LogNumber("sendNAL", len);
  
      RTMPPacket * packet;
  
      long timeoffset = GetTickCount() - startTime;
  
  
  
      if (buf[2] == 0x00) { //00 00 00 01
  
          buf += 4;
  
          len -= 4;
  
      }
  
      else if (buf[2] == 0x01) { //00 00 01
  
          buf += 3;
  
          len -= 3;
  
      }
  
      else
  
      {
  
          Logging::LogStdString("INVALID x264 FRAME!");
  
      }
  
      int type = buf[0] & 0x1f;   
  
      int maxNALSize = 1200;
  
  
  
      if (len <= maxNALSize)
  
      {
  
          packet = (RTMPPacket *)malloc(RTMP_HEAD_SIZE + len + 9);
  
          memset(packet, 0, RTMP_HEAD_SIZE);
  
  
  
          packet->m_body = (char *)packet + RTMP_HEAD_SIZE;
  
          packet->m_nBodySize = len + 9;
  
  
  
          unsigned char *body = (unsigned char *)packet->m_body;
  
          memset(body, 0, len + 9);
  
  
  
          body[0] = 0x27;
  
          if (type == NAL_SLICE_IDR) {
  
              body[0] = 0x17;
  
          }
  
  
  
          body[1] = 0x01;   //nal unit
  
          body[2] = 0x00;
  
          body[3] = 0x00;
  
          body[4] = 0x00;
  
  
  
          body[5] = (len >> 24) & 0xff;
  
          body[6] = (len >> 16) & 0xff;
  
          body[7] = (len >> 8) & 0xff;
  
          body[8] = (len) & 0xff;
  
  
  
          memcpy(&body[9], buf, len);
  
  
  
          packet->m_hasAbsTimestamp = 0;
  
          packet->m_packetType = RTMP_PACKET_TYPE_VIDEO;
  
          if (rtmp != NULL) {
  
              packet->m_nInfoField2 = rtmp->m_stream_id;
  
          }
  
          packet->m_nChannel = 0x04;
  
          packet->m_headerType = RTMP_PACKET_SIZE_LARGE;
  
          packet->m_nTimeStamp = timeoffset;
  
  
  
          if (rtmp != NULL) {
  
              RTMP_SendPacket(rtmp, packet, QUEUE_RTMP);
  
          }
  
          free(packet);
  
      }
  
      else
  
      {
  
          packet = (RTMPPacket *)malloc(RTMP_HEAD_SIZE + maxNALSize + 90);
  
          memset(packet, 0, RTMP_HEAD_SIZE);      
  
  
  
          // split large NAL into multiple smaller ones:
  
          int sentBytes = 0;
  
          bool firstFragment = true;
  
          while (sentBytes < len)
  
          {
  
              // decide how many bytes to send in this fragment:
  
              int fragmentSize = maxNALSize;
  
              if (sentBytes + fragmentSize > len)
  
                  fragmentSize = len - sentBytes;
  
              bool lastFragment = (sentBytes + fragmentSize) >= len;
  
  
  
              packet->m_body = (char *)packet + RTMP_HEAD_SIZE;
  
              int headerBytes = firstFragment ? 10 : 2;
  
              packet->m_nBodySize = fragmentSize + headerBytes;
  
  
  
              unsigned char *body = (unsigned char *)packet->m_body;
  
              memset(body, 0, fragmentSize + headerBytes);
  
  
  
              //key frame
  
              int NALtype = 0x27;
  
              if (type == NAL_SLICE_IDR) {
  
                  NALtype = 0x17;
  
              }
  
  
  
              // Set FU-A indicator
  
              body[0] = (byte)((NALtype & 0x60) & 0xFF); // FU indicator NRI
  
              body[0] += 28; // 28 = FU - A (fragmentation unit A) see RFC: https://tools.ietf.org/html/rfc3984
  
  
  
              // Set FU-A header
  
              body[1] = (byte)(NALtype & 0x1F);  // FU header type
  
              body[1] += (firstFragment ? 0x80 : 0) + (lastFragment ? 0x40 : 0); // Start/End bits
  
  
  
              body[2] = 0x01;   //nal unit
  
              body[3] = 0x00;
  
              body[4] = 0x00;
  
              body[5] = 0x00;
  
  
  
              body[6] = (len >> 24) & 0xff;
  
              body[7] = (len >> 16) & 0xff;
  
              body[8] = (len >> 8) & 0xff;
  
              body[9] = (len) & 0xff;
  
  
  
              //copy data
  
              memcpy(&body[headerBytes], buf + sentBytes, fragmentSize);
  
  
  
              packet->m_hasAbsTimestamp = 0;
  
              packet->m_packetType = RTMP_PACKET_TYPE_VIDEO;
  
              if (rtmp != NULL) {
  
                  packet->m_nInfoField2 = rtmp->m_stream_id;
  
              }
  
              packet->m_nChannel = 0x04;
  
              packet->m_headerType = RTMP_PACKET_SIZE_LARGE;
  
              packet->m_nTimeStamp = timeoffset;
  
  
  
              if (rtmp != NULL) {
  
                  RTMP_SendPacket(rtmp, packet, TRUE);
  
              }
  
  
  
              sentBytes += fragmentSize;
  
              firstFragment = false;
  
          }
  
  
  
          free(packet);
  
      }
  
  }

• Our latest improvement to QA : Screenshot Testing

  2 octobre 2013, par benaka — Development

  Introduction to QA in Piwik

  Like any piece of good software, Piwik comes with a comprehensive QA suite that includes unit and integration tests. The unit tests make sure core components of Piwik work properly. The integration tests make sure Piwik’s tracking and report aggregation and APIs work properly.

  To complete our QA suite, we’ve recently added a new type of tests : Screenshot tests, that we use to make sure Piwik’s controller and JavaScript code works properly.

  This blog post will explain how they work and describe our experiences setting them up ; we hope to show you an example of innovative QA practices in an active open source project.

  Screenshot Tests

  As the name implies, our screenshot tests (1) first capture a screenshot of a URL, then (2) compare the result with an expected image. This lets us test the code in Piwik’s controllers and Piwik’s JavaScript simply by specifying a URL.

  Contrast this with conventional UI tests that test for page content changes. Such tests require writing large amounts of test code that, at most, check for changes in HTML. Our tests, on the otherhand, will be able to show regressions in CSS and JavaScript rendering logic with a bare minimum of testing code.

  Capturing Screenshots

  Screenshots are captured using a 3rd party tool. We tried several tools before settling on PhantomJS. PhantomJS executes a JavaScript file with an environment that allows it to create WebKit powered web views. When capturing a screenshot, we supply PhantomJS with a script that :

  • opens a web page view,
  • loads a URL,
  • waits for all AJAX requests to be completed,
  • waits for all images to be loaded
  • waits for all JavaScript to be run.

  Then it renders the completed page to an PNG file.

  • To see how we use PhantomJS see capture.js.
  • To see how we wait for AJAX requests to complete and images to load see override.js.

  Comparing Screenshots

  Once a screenshot is generated we test for UI regressions by comparing it with an expected image. There is no sort of fuzzy matching involved. We just check that the images consist of the same bytes.

  If a screenshot test fails we use ImageMagick’s compare command line tool to generate an image diff :

  

  In this example above, there was a change that caused the Search box to be hidden in the datatable. This resulted in the whole Data table report being shifted up a few pixels. The differences are visible in red color which gives rapid feedback to the developers what has changed in the last commit.

  Screenshot Tests on Travis

  We experienced trouble generating identical screenshots on different machines, so our tests were not initially automated by Travis. Once we surpassed this hurdle, we created a new github repo to store our UI tests and screenshots and then enabled the travis build for it. We also made sure that every time a commit is pushed to the Piwik repo, our travis build will push a commit to the UI test repo to run the UI tests.

  We decided to create a new repository so the main repository wouldn’t be burdened with the large screenshot files (which git would not handle very well). We also made sure the travis build would upload all the generated screenshots to a server so debugging failures would be easier.

  Problems we experienced

  Getting generated screenshots to render identically on separate machines was quite a challenge. It took months to figure out how to get it right. Here’s what we learned :

  Fonts will render identically on different machines, but different machines can pick the wrong fonts. When we first tried getting these tests to run on Travis, we noticed small differences in the way fonts were rendered on different machines. We thought this was an insurmountable problem that would occur due to the libraries installed on these machines. It turns out, the machines were just picking the wrong fonts. After installing certain fonts during our Travis build, everything started working.

  Different versions of GD can generate slightly different images. GD is used in Piwik to, among other things, generate sparkline images. Different versions of GD will result in slightly different images. They look the same to the naked eye, but some pixels will have slightly different colors. This is, unfortunately, a problem we couldn’t solve. We couldn’t make sure that everyone who runs the tests uses the same version of GD, so instead we disabled sparklines for UI testing.

  What we learned about existing screenshot capturing tools

  We tried several screenshot capturing tools before finding one that would work adequately. Here’s what we learned about them :

  • CutyCapt This is the first screenshot capturing tool we tried. CutyCapt is a C++ program that uses QtWebKit to load and take a screenshot of a page. It can’t be used to capture multiple screenshots in one run and it can’t be used to wait for all AJAX/Images/JavaScript to complete/load (at least not currently).

  • PhantomJS This is the solution we eventually chose. PhantomJS is a headless scriptable browser that currently uses WebKit as its rendering engine.

    For the most part, PhantomJS is the best solution we found. It reliably renders screenshots, allows JavaScript to be injected into pages it loads, and since it essentially just runs JavaScript code that you provide, it can be made to do whatever you want.

  • SlimerJS SlimerJS is a clone of PhantomJS that uses Gecko as the rendering engine. It is meant to function similarly to PhantomJS. Unfortunately, due to some limitations hard-coded in Mozilla’s software, we couldn’t use it.

    For one, SlimerJS is not headless. There is, apparently, no way to do that when embedding Mozilla. You can, however, run it through xvfb, however the fact that it has to create a window means some odd things can happen. When using SlimerJS, we would sometimes end up with images where tooltips would display as if the mouse was hovering over an element. This inconsistency meant we couldn’t use it for our tests.

  One tool we didn’t try was Selenium Webdriver. Although Selenium is traditionally used to create tests that check for HTML content, it can be used to generate screenshots. (Note : PhantomJS supports using a remote WebDriver.)

  Our Future Plans for Screenshot Testing

  At the moment we render a couple dozen screenshots. We test how our PHP code, JavaScript code and CSS makes Piwik’s UI look, but we don’t test how it behaves. This is our next step.

  We want to create Screenshot Unit Tests for each UI control Piwik uses (for example, the Data Table View or the Site Selector). These tests would use the Widgetize plugin to load a control by itself, then execute JavaScript that simulates events and user behavior, and finally take a screenshot. This way we can test how our code handles clicks and hovers and all sorts of other behavior.

  Screenshots Tests will make Piwik more stable and keep us agile and able to release early and often. Thank you for your support & Spreading the word about Piwik !

• Appending a list of movies MP4s causes the sound to be dropped or garbled at some point

  9 février 2020, par Marie

  Update I am able to reproduce the issue by concatenating 10 Hello.mp4 clips and see the audio drop out/garbled at about 5 seconds playback. This is via VLC latest 3.0.8 on Windows7 64bit. Window Player zero sound. Media Player Classic it plays fine all 10 audio or the word "Hello". The same movie when dragged onto Whatsapp the PC app plays OK but no sound if played from the Phone Whatsapp. Perhaps its my computer too slow in the production of this clip ??? I don’t know what to trust anymore.

  I copied the same ffmpeg.exe onto my kid’s Windows10 laptop and was able to produce the same behavior with sound dropping out with VLC however Windows10 media player is able to play the audio without a glitch.

  You can reproduce the same on your end with this batch file

  _HELLO_MP4s.CMD

  rem 2:07 AM 2/8/2020
  
  rem 
  
  rem  
  
  SET EXE="S:\_BINS\FFmpeg 4.2.1 20200112\bin\ffmpeg.exe"
  
  
  
  SET ROOTPATH=.\
  
  
  
  SET OUT_FILE="%ROOTPATH%HELLOs.MP4"
  
  
  
  SET IN_FILES_LIST="%ROOTPATH%IN_FILES_LIST.TXT"
  
  ECHO file '%ROOTPATH%HELLO.mp4' > %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  ECHO file '%ROOTPATH%HELLO.mp4' >> %IN_FILES_LIST% 
  
  
  
  SET OPTIONS= -f concat -safe 0 -i  %IN_FILES_LIST%  -c copy -y  %OUT_FILE%
  
  
  
  SET INFO_FILE="INFO.TXT"
  
  
  
  %EXE% %OPTIONS%  1> %INFO_FILE% 2>&1 
  
  
  
  ECHO ======================== >> %INFO_FILE% 
  
  ECHO OUT_FILE=%OUT_FILE%  >> %INFO_FILE% 
  
  ECHO EXE=%EXE%  >> %INFO_FILE%
  
  ECHO OPTIONS=%OPTIONS%  >> %INFO_FILE% 
  
  ECHO ======================== >> %INFO_FILE%

  Original Post
  My process is in 3 steps
  Step 1) Corresponding to each bitmap I have 00.JPG ... NN.JPG I combine a list of "SOURCE" mp3 audio into a single audio mp3 to produce matching 00.MP3 ... NN.MP3

  I had glitch here where one my mp3 was not of the correct Sample Rate, however a kind soul in this forum helped me fix that.
  You can read the details here :

  When I append a silent audio (mp3) to an existing list of audio it garbles the final audio ?

  Step 2) combine each mp3 from previous with a the filename matching bitmap to produce a movie .MP4

  IOW,

  • 00.JPG + 00.MP3 >> 00.MP4
  • 01.JPG + 01.MP3 >> 01.MP4
  • and so on

  From this run of 24 subparts, I hand tested some of these movies against Whatsapp and they are accepted fine.
  However, the final MOVIE.MP4 is not.
  I will list below their info from ffprobe.

  Step 3) combine the list of movies from previous into a final MOVIE.MP4
  This is where I have been having random issues typically with audio, currently this audio drops at about 20s from start. Corresponding to roughly movies parts 04.mp4 to 07.mp4

  I play the videos via VLC but Windows Media Player has even worse playback.

  I am able to reproduce Step3 and thus MOVIE.MP4 with following batch file

  rem 10:33 PM 2/6/2020
  
  SET EXE="S:\_BINS\FFmpeg 4.2.1 20200112\bin\ffmpeg.exe"
  
  
  
  SET ROOTPATH=.\
  
  
  
  SET OUT_FILE="%ROOTPATH%MOVIE.MP4"
  
  
  
  SET IN_FILES_LIST="%ROOTPATH%IN_FILES_LIST.TXT"
  
  
  
  SET OPTIONS= -f concat -safe 0 -i  %IN_FILES_LIST%  -c copy -y  %OUT_FILE%
  
  
  
  SET INFO_FILE="INFO.TXT"
  
  
  
  %EXE% %OPTIONS%  1> %INFO_FILE% 2>&1 
  
  
  
  rem PAUSE

  The content of IN_FILES_LIST.TXT

  file '00.mp4'
  
  file '01.mp4'
  
  file '02.mp4'
  
  ...
  
  file '23.mp4'
  
  file '24.mp4'

  (Step 2) uses the following :)
  

  The following is ffprobe on the source audio MP3s (Step 1)

  MP3s_ORIGINAL.TXT
  
  ========================BEGIN 
  
  [mp3 @ 0000000000513100] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\00.mp3':
  
    Duration: 00:00:03.36, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000003f3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\01.mp3':
  
    Duration: 00:00:00.46, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000004a3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\02.mp3':
  
    Duration: 00:00:00.58, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000623180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\03.mp3':
  
    Duration: 00:00:00.84, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000003a3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\04.mp3':
  
    Duration: 00:00:00.86, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000433180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\05.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000683180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\06.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000004d3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\07.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000004c3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\08.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000573180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\09.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000583180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\10.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 00000000005e3180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\11.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000553180] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, mp3, from '.\PLAY\12.mp3':
  
    Duration: 00:00:00.98, start: 0.000000, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  [mp3 @ 0000000000563180] Estimating duration from bitrate, this may be inaccurate
  
  
  
  
  
  trimmed because SO limits post to 30000 chars

  The following is ffprobe on the MP3s concatenated with 2second Silence. All their Sample Rate 24K and Bit Rate 32k seems OK ?? (Also Step 1)

  MP3s_withSilenceAppended.TXT
  
  ========================BEGIN 
  
  Input #0, mp3, from '00.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:05.42, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '01.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.52, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '02.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.64, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '03.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.90, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '04.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.93, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '05.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '06.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '07.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '08.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '09.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '10.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '11.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '12.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '13.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:05.81, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '14.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.93, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '15.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.66, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '16.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.66, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '17.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.66, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '18.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.83, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '19.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:06.50, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '20.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '21.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.05, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '22.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.14, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '23.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:06.12, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
  
  Input #0, mp3, from '24.mp3':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.14, start: 0.046042, bitrate: 32 kb/s
  
      Stream #0:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s

  The following is ffmpeg info output during the production of final movie MOVIE.MP4
  (Step 3)

  ========================BEGIN 
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\00.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:05.54, start: 0.000000, bitrate: 174 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 137 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\01.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.71, start: 0.000000, bitrate: 269 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 242 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\02.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.71, start: 0.000000, bitrate: 285 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 245 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\03.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.04, start: 0.000000, bitrate: 275 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 239 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\04.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.04, start: 0.000000, bitrate: 286 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 250 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\05.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 281 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 249 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\06.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 281 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 249 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\07.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 150 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 115 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\08.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 201 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 166 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\09.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 247 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 214 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\10.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 247 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 214 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\11.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 131 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 95 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\12.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 194 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 159 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\13.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:05.88, start: 0.000000, bitrate: 207 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 169 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\14.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.04, start: 0.000000, bitrate: 335 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 300 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\15.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.88, start: 0.000000, bitrate: 365 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 342 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\16.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.88, start: 0.000000, bitrate: 384 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 362 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\17.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:02.88, start: 0.000000, bitrate: 390 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 368 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\18.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.04, start: 0.000000, bitrate: 386 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 363 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\19.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:06.71, start: 0.000000, bitrate: 204 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 169 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\20.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 194 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 159 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\21.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 194 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 159 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\22.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 208 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 169 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\23.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:06.21, start: 0.000000, bitrate: 204 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 166 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\24.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:00:03.21, start: 0.000000, bitrate: 173 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 134 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '\VID\MOVIE.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.35.101
  
    Duration: 00:01:29.05, start: 0.000000, bitrate: 239 kb/s
  
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 203 kb/s, 23.53 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 30 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  I have not been able yet to reproduce the issue with a smaller set of movies, in the meantime if you would to get a copy I would have to upload an archive to a link so you can have them on your side.

  Alternatively, if you would like me to provide additional info from these steps let me know what commands and I will be happy to provide.

  Thank you.