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• Concatenate videos with audio and overlay with complex Filtergraph in FFMPEG [closed]

  15 octobre 2024, par Jamie Shepherd

  I am new to FFMPEG and trying to get my head around the concepts and the syntax.

  


  I have 3 video files that I am trying to concatenate into one file, while overlaying an image on the middle video, all while maintaining the audio. Sadly however there is not many assurances on these files so the resolutions could be different, different audio channels etc. The documentation on the "concat" video filter states that :

  


  


  All corresponding streams must have the same parameters in all segments

  


  


  As such I have tried to use a complex filtergraph to scale all videos to the same resolution before using concat however I am getting an Unable to choose an output format error and don't fully understand what it means. The command I have so far is this :

  


  ffmpeg \
  -i intro.mp4 \
  -i main.mp4 \
  -i outro.mp4 \
  -i imageOverlay.png \
  -filter_complex \
  '[0] scale=1920:1800 [scaledIntro];' \
  '[1] scale=1920:1800 [scaledMain];' \
  '[2] scale=1920:1800 [scaledOutro];' \
  '[3] scale=1920:1800 [scaledOverlay];' \
  '[scaledMain][scaledOverlay] scale=1920:1800 [scaledOverlayOutro];' \
  '[scaledIntro:v] [scaledIntro:a] [scaledMain:v] [scaledOverlayOutro:a] [scaledOverlayOutro:v] [scaledOutro:a] concat=n=3:v=1:a=1 [v][a];' \
  -map '[v]' -map '[a]' files/output/output.mp4


  


  The error I get is :

  


  [AVFormatContext @ 0x121f08d40] Unable to choose an output format for '[1] scale=1920:1800 [scaledMain];'; use a standard extension for the filename or specify the format manually.
[out#0 @ 0x121f08c80] Error initializing the muxer for [1] scale=1920:1800 [scaledMain];: Invalid argument
Error opening output file [1] scale=1920:1800 [scaledMain];.
Error opening output files: Invalid argument


  


  Would love to understand what is going on here.

  


  Have I made a syntax mistake ? Am I missing something conceptually here ?

  


  Many thanks for your time

  


• Q&A : An interview with Matomo founder, Matthieu Aubry

  20 novembre 2018, par Joselyn Khor — About, Community

  Hey everyone ! Joselyn here. As always the views of our community remain top of mind. So to make sure you guys know the thinking behind these new projects, we reached out to Matomo’s founder, Matthieu, to ask questions you might want answered. Please check it out below !

  Hi guys, it’s Matthieu ! Here to answer some questions about the rebrand and the future of Matomo and Innocraft.

  What’s upcoming ?

  We’ve been busy implementing our rebrand into all aspects of Matomo and there’s also our new website, which is launching today ! The new website will help people better understand what Matomo is and how they can benefit from using modern web analytics.

  Why was Matomo and Innocraft brought onto one website ?

  In the past the separation caused a bit of confusion so we’re taking this as a chance to unite both the business brand, Innocraft and community brand, Matomo, on one website. Putting our focus on one brand, Matomo, makes it easier for people to see us with fresh eyes. We have a community side as well as a business side and while the community is still incredibly important to us, we find we have a powerful analytics tool that is capable of helping businesses too.

  Is Matomo becoming commercial or turning corporate ?

  No. nothing is changing. Matomo is still an open-source project and community. Although we’ll have a pricing page and “start free trial” on the new website brought over from Innocraft.cloud, the Matomo community will still play the biggest part on the Matomo website. We have dedicated sections focused on Community and On-Premise.

  The rebrand exercise helped us gain a refreshed perspective. After reflecting on how far we’ve come, we can feel more confident about Matomo Analytics itself as a platform. We believe it’s a great chance to bring that confidence into the brand and vision. We are proud that it’s an awesome open-source platform and at the same time it’s also powerful as a tool for businesses.

  Why is there no ‘download for free’ button on the homepage ?

   

  
  We feel many users coming to the site will get confused about our hosting options (Cloud and On-Premise) which is something you don’t usually consider when choosing an analytics tool.

  The reason for us to not have that button is when people see a “download for free” button on the homepage next to a “try it for free” button, it creates confusion. For those who do choose to download Matomo often become confused when they are left with a .zip file unaware how to install it and the technical requirements of self-hosting. We feel presenting our users with the simplest installation option first will give them the best chance possible to try Matomo to its full potential, without cost.

  And you can still find the link to Download Matomo in the footer of each page.
  

   

  Is Matomo still free to download and have forever ?

  Absolutely. The free open-source download can be found on the On-Premise section of the website, or download Matomo here.

  Why is it important to have a business behind the project ?

  There’s the reality that we have to make money in order for the Matomo project to survive … and thrive. The reason we still need a business side (Innocraft) is to fund and sustain the Matomo project. Whenever people purchase premium features, this helps finance the development of Matomo for our community.

  Because of the business we’re able to continually maintain and develop Matomo for you guys as well as future users. For example, the next release Matomo 3.8.0 is already mostly developed and will bring lots of interesting features too, like the two-factor authentication, Brute Force Protection, failed tracking requests reporting, lots of JavaScript tracker improvements, a new total summary row below reports, and many more security fixes, bug fixes, and other new features.

  So we see a business being very helpful in supporting our open-source community. Without a business side, our free, open-source project would not be able to survive.

  How will you protect the Matomo project ?

  We’ve ensured the Matomo project will be protected for the future as we wish to turn it into a not-for-profit foundation.

  We’ve also got a safeguard where the open-source code will stay under a GPL license forever. This is so we can guarantee, that no matter what happens, the Matomo project itself will stay completely free software.

  Is there a way for people to help ?

  There are heaps of ways to help ! You can help other Matomo users in the forums, contribute to fixes on GitHub, leave a great review (e.g. alternativeTo), help look for bugs with our Security Bounty Programme or participate and spread the word about Matomo in our community social media pages – Mastodon, Facebook, Twitter. Telling your friends about us would be very helpful too !

  What’s planned for the future ?
  We’ve worked hard to become the #1 open-source analytics platform (1.4 million websites use Matomo today), but now we need to empower even more individuals and businesses to take back control of their own data.

  Showing our community that we have a powerful platform is crucial, but alongside that our values are what define us. User privacy is still of utmost importance and we’re here to make it known that power needs to rest in the hands of people and not large corporations.

  You can rest easy knowing you’re doing your part in using trustworthy and dependable tools. By joining many other companies who are growing this movement to decentralise the Internet, we can build a safer, online world together.

  Join this analytics revolution and let us know what you think about Matomo !

• How to extract fully synced audio with ffmpeg ?

  2 janvier 2023, par Brendan Hill

  I have an MP4 file with video and audio. I need to extract the audio stream only to an MP3 file.

  


  However it is critical for our application that the timing / synchronization of the audio file is exactly aligned with the original video, as we cross-correlate audio features based on timing.

  


  I currently use this command :

  


  ffmpeg -y 
   -v error 
   -map 0:a ./the-output-file-mp3
   -map 0:v ~/a-dummy-video-output-file.mp4
   -i ~/the-input-file.mp4
   -acodec copy 
  


  


  as I read somewhere that mapping both 0:a and 0:v would guarantee alignment & synchronization. I then discard the video file as it is not needed.

  


  However it is orders of magnitude faster to just extract the audio instead :

  


  ffmpeg -y 
   -v error 
   -map 0:a ./the-output-file-mp3
   -i ~/the-input-file.mp4
   -acodec copy 


  


  But I don't know if this guarantees alignment, because I read on this page that :

  


  If you only extract audio from a video stream, the length of the audio may be shorter than the length of the video. To make sure this doesn't happen, extract both audio AND video with the same call to ffmpeg, e.g. "ffmpeg -i vid.avi -map 0:a audio.wav -map 0:v onlyvideo.avi

  


  However perhaps I am putting too much weight on that comment. I don't care if the audio clip finishes early, but it is critical that it does not start late, or get de-synced from the original video at any point.

  


  What is the most efficient way with ffmpeg to extract the audio stream with a guarantee that it is 100% aligned in time to the video (and starts at exactly the same time) ?

  


  Will this method guarantee alignment ?

  


  ffmpeg -y 
   -v error 
   -i ~/the-input-file.mp4
   -vn
   -acodec copy 
   ~/the-output-file.mp4