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• FFMPEG failing in AWS Lambda

  18 février 2019, par Zaid Amir

  I am trying to create a transcoding function for short videos. The function is hosted on AWS Lambda. The problem is that AWS lambda seems to be missing something that FFMPEG requires, at least according to Amazon.

  I contacted Amazon earlier and this is their response to the issue :

  We found that the FFMPEG operations require at least libx264 and an
  acc library, both of which will have dependencies of their own. To
  troubleshoot the issue it will involve diving deeper into the full
  dependency chain. We can see that it works in the Amazon Linux
  environment however, the environment is similar but not identical to
  the lambda environment. There can be some dependencies that exist in
  Amazon Linux but not in lambda environment as Lambda runs on the
  container. Here, as FFmpeg is a third party software, diving deeper
  into the dependency chain and verifying the version compatibilities is
  very hard to do. Unfortunately going further, this is bound to go into
  architecture and code support which is out of AWS Support scope 1. I
  hope you understand our limitations. However should FFmpeg support
  have any questions specific to the Lambda platform, please do let us
  know and we will be happy to assist. We will be in better position to
  investigate further once you receive an update from the FFmpeg support
  suggesting an issue from Lambda end.

  Upon AWS suggestion, I contacted FFMPEG on the developers mailing list, my message was rejected with the reason being that its more suited to ffmpeg users mailing list than developers. I sent an email to ’ffmpeg-user@ffmpeg.org’ a week ago and did not get any response yet.

  I then went and built a dynamically linked ffmpeg version making sure to package all libraries, checked ddl on each one, then made a small lambda function that looped over all binaries and ddled each one of them, compared that to the output I got from Amazon Linux and the same dependencies/versions exists on both lambda and the AWS Linux instance yet ffmpeg still fails on lambda.

  You can find a detailed log file here : https://www.datafilehost.com/d/6e5e21bb

  And this is a sample of the errors I’m getting, repeated across the entire log file :

  2018-08-14T12:27:10.874Z [h264 @ 0x65c2fc0] concealing 2628 DC, 2628
  AC, 2628 MV errors in P frame

  2018-08-14T12:27:10.874Z [aac @ 0x65d2f00] channel element 2.11 is not
  allocated

  2018-08-14T12:27:10.874Z Error while decoding stream #0:1 : Invalid
  data found when processing input

  2018-08-14T12:27:10.874Z [h264 @ 0x67e86c0] Invalid NAL unit size
  (108085662 > 1649).

  2018-08-14T12:27:10.874Z [h264 @ 0x67e86c0] Error splitting the input
  into NAL units.

  2018-08-14T12:27:10.874Z [aac @ 0x65d2f00] channel element 2.0 is not
  allocated

  2018-08-14T12:27:10.874Z Error while decoding stream #0:1 : Invalid
  data found when processing input

  2018-08-14T12:27:10.874Z [h264 @ 0x68189c0] Invalid NAL unit size
  (71106974 > 1085).

  2018-08-14T12:27:10.874Z [h264 @ 0x68189c0] Error splitting the input
  into NAL units.

  2018-08-14T12:27:10.874Z [aac @ 0x65d2f00] Pulse tool not allowed in
  eight short sequence.

  This log is generated when trying to perform an HLS transcoding on this file : https://www.datafilehost.com/d/999a4492

  Note that the issue is not related to that file alone nor is it related to HLS, its general and happen on all videos and any ffmpeg command that tries to seek the stream, even tried extracting a single frame from a video using the simplest form possible for example : ffmpeg -ss 00:00:02 -I file.mp4 -vframes 1 -y output.jpg also fails with the same errors in the log file.

  Not sure how to debug this further. Tried enabling debug logs with ‘-loglevel debug’ but did not give me any extra info. Any help or suggestions

• Inputting Audio Stream to FFMPEG

  5 avril 2018, par Wijaya

  I’m building a real time chat application with C# and ffmpeg.exe. My requirement is to get a memory stream from Microsoft Speech API and feed it to ffmpeg process in real time. I can take a memory stream from Microsoft Speech API. I’m using following code to create the memory stream.

          using (MemoryStream stream = new MemoryStream())
  
          {
  
              MemoryStream streamAudio = new MemoryStream();
  
              System.Media.SoundPlayer m_SoundPlayer = new System.Media.SoundPlayer();
  
              _speechSynthesizerVisemesSender.SetOutputToWaveStream(streamAudio);
  
              _speechSynthesizerVisemesSender.SetOutputToNull();
  
              stream.WriteTo(proc.StandardInput.BaseStream);
  
          }   

  I’m already using another datapipe with another command to feed video content to ffmpeg. But I couldn’t find a stable solution to feed audio through a datapipe. This article briefly explains about audio datapipe. I’m using following command to stream audio.

  "ffmpeg -re -f s16le -i pipe:wav -f mpegts udp://127.0.0.1:1234"

  But it is not working with the datapipe. If I try the command with mp3 or wav file, it works.

• WhatsApp video as Gif sharing on Android programatically

  2 novembre 2017, par Razec Luar

  How can i convert a mp4 video file to a WhatsApp gif file (it’s simple showed as gif inside app UI but internally is a specific mp4 format) to be use in android share intent, being recognized as this type of media by whatsapp chat app ???

  I search a lot but i can’t find any information from WhatsApp docs (they don’t have this kind of doc anyway) or any dev with the same problem as i.

  WHAT I HAVE :

  I have discovered that at beginning of whatsapp "gif" mp4 files is present a loop value if you read they on hex editor, all files have this. Remove this value make whatsapp receive as regular video (not sharing as gif).

  How can i add this value using ffmpeg encoding ? (editing my mp4 files manually with this value corrupt the files, maybe i have to fix some mp4 header index that i don’t know yet...)

  
  

  FIRST 80 BYTES in hexadecimal (from beginning to start of "moov" atom from mp4 structure) :

  00 00 00 1C 66 74 79 70 6D 70 34 32 00 00 00 01 6D 70 34 31 6D 70 34 32 69 73 6F 6D 00 00 00 18 62 65 61 6D 01 00 00 00 01 00 00 00 00 00 00 00 05 00 00 00 00 00 00 0C 6C 6F 6F 70 00 00 00 00 00 00 00 08 77 69 64 65 00 00 04 9F 6D 6F 6F 76

  A short mp4 file generated by WhatsApp that internally (at app) was showed as a Gif (with different UI) :

  https://www.dropbox.com/s/kpynmx1bg3z76lz/VID-20171024-WA0009.mp4?dl=0