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• using ffmpeg implementation live video/audio

  14 mars 2018, par geeeek

  I am going to implementation live video/audio service using ffmpeg.

  I am using embedded board with camera, mic. Receiver is android phone.

  as summary :
  sender : embedded board.
  receiver : android phone.

  I have an embedded board with a camera and a microphone. The camera’s data is raw h264 data, and the audio data is raw pcm data. I want to do live video communication with Android phone, but I do not know how.

  I would like to mux two data with ffmpeg and send it, but I do not know if it is possible. Thank you for your advice.

  I can not be sure because I have no experience about ffmpeg in live.

  About above enviroment please suggest your best methods.

• Transcoding Modern Formats

  17 août 2014

  I’ve noticed that this blog still gets a decent amount of traffic, particularly to some of the older articles about transcoding. Since I’ve been working on a tool in this space recently, I thought I’d write something up in case it helps folks unravel how to think about transcoding these days.

  The tool I’ve been working on is EditReady, a transcoding app for the Mac. But why do you want to transcode in the first place ?

  Dailies

  After a day of shooting, there are a lot of people who need to see the footage from the day. Most of these folks aren’t equipped with editing suites or viewing stations - they want to view footage on their desktop or mobile device. That can be a problem if you’re shooting ProRes or similar.

  Converting ProRes, DNxHD or MPEG2 footage with EditReady to H.264 is fast and easy. With bulk metadata editing and custom file naming, the management of all the files from the set becomes simpler and more trackable.

  One common workflow would be to drop all the footage from a given shot into EditReady. Use the "set metadata for all" command to attach a consistent reel name to all of the clips. Do some quick spot-checks on the footage using the built in player to make sure it’s what you expect. Use the filename builder to tag all the footage with the reel name and the file creation date. Then, select the H.264 preset and hit convert. Now anyone who needs the footage can easily take the proxies with them on the go, without needing special codecs or players, and regardless of whether they’re working on a PC, a Mac, or even a mobile device.

  If your production is being shot in the Log space, you can use the LUT feature in EditReady to give your viewers a more traditional "video levels" daily. Just load a basic Log to Video Levels LUT for the batch, and your converted files will more closely resemble graded footage.

  Mezzanine Formats

  Even though many modern post production tools can work natively with H.264 from a GoPro or iPhone, there are a variety of downsides to that type of workflow. First and foremost is performance. When you’re working with H.264 in an editor or color correction tool, your computer has to constantly work to decompress the H.264 footage. Those are CPU cycles that aren’t being spent generating effects, responding to user interface clicks, or drawing your previews. Even apps that endeavor to support H.264 natively often get bogged down, or have trouble with all of the "flavors" of H.264 that are in use. For example, mixing and matching H.264 from a GoPro with H.264 from a mobile phone often leads to hiccups or instability.

  By using EditReady to batch transcode all of your footage to a format like ProRes or DNxHD, you get great performance throughout your post production pipeline, and more importantly, you get consistent performance. Since you’ll generally be exporting these formats from other parts of your pipeline as well - getting ProRes effects shots for example - you don’t have to worry about mix-and-match problems cropping up late in the production process either.

  Just like with dailies, the ability to apply bulk or custom metadata to your footage during your initial ingest also makes management easier for the rest of your production. It also makes your final output faster - transcoding from H.264 to another format is generally slower than transcoding from a mezzanine format. Nothing takes the fun out of finishing a project like watching an "exporting" bar endlessly creep along.

  Modernization

  The video industry has gone through a lot of digital formats over the last 20 years. As Mac OS X has been upgraded over the years, it’s gotten harder to play some of those old formats. There’s a lot of irreplaceable footage stored in formats like Sorensen Video, Apple Intermediate Codec, or Apple Animation. It’s important that this footage be moved to a modern format like ProRes or H.264 before it becomes totally unplayable by modern computers. Because EditReady contains a robust, flexible backend with legacy support, you can bring this footage in, select a modern format, and click convert. Back when I started this blog, we were mostly talking about DV and HDV, with a bit of Apple Intermediate Codec mixed in. If you’ve still got footage like that around, it’s time to bring it forward !

  Output

  Finally, the powerful H.264 transcoding pipeline in EditReady means you generate beautiful deliverable H.264 more rapidly than ever. Just drop in your final, edited ProRes, DNxHD, or even uncompressed footage and generate a high quality H.264 for delivery. It’s never been this easy !

  See for yourself

  We released a free trial of EditReady so you can give it a shot yourself. Or drop me a line if you have questions.

• Time issues in ffmpeg script (MP4 to MP3 conversion)

  16 février 2018, par Alex

  I use the code below as script on my Debian PC to create MP3 files from MP4 video files for adding to podcast app on android phone.

  But each time I click pause/forward time position (not indication) is set up in random way after resuming. Please help improve the code below to solve this problem.

  for f in *.mp4; do
  
    ffmpeg -i "$f" -map 0:a -codec:a libmp3lame -b:a 96k "${f%.mp4}.mp3"
  
  done
  
  for f in *.mp3; do
  
    vbrfix -always -makevbr -lameinfo "$f" "${f%.mp3}.mp3"
  
    rm -rf vbrfix.log vbrfix.tmp
  
  done