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• How to record (and process ?) a video that is streamable from Android

  13 mai 2016, par afollestad

  My company’s app relies heavily on video recording and playback of web-based videos. I use the MediaRecorder API to record videos, through this library designed by me : https://github.com/afollestad/material-camera.

  For playback, I use this library which is basically a wrapper around Google’s ExoPlayer library : https://github.com/brianwernick/ExoMedia.

  It works fine for the most part with small videos, especially if I decrease bit rates for audio and video. However, larger and higher quality videos have many issues. Sometimes they seem to buffer forever, sometimes playback doesn’t even start successfully, etc. Again, these videos are being streamed over HTTP from Amazon S3.

  ---

  I’ve read a little bit about FFMPEG, and how it can process MP4’s for "faststart", splitting the files into chunks for DASH, etc. However, FFMPEG solutions for Android seem a bit complex, so...

  Is there anyway to record MP4’s from Android, with MediaRecorder, MediaCodec, or some other API which results in a video file that is fast to stream ? It amazes me how well Snapchat has figured this out.

• Carrierwave video not being processsed before uploading to S3

  12 décembre 2013, par Cramps

  I'm using Carrierwave, Carrierwave-video and Carrierwave-video-thumbnailer to process videos and make a thumbnail when they're uploaded. This was all working nicely while I was saving the files on my file system. However, now that I've added uploading to Amazon S3 using the carrierwave-aws gem, the videos are being uploaded to S3 without being processed first. It's as if the process encode_video and version :thumb are being skipped by the uploader.

  Here's what was working for me at first (before adding S3) :

  class VideoUploader < CarrierWave::Uploader::Base
  
  
  
  include CarrierWave::Video
  
  include CarrierWave::Video::Thumbnailer
  
  
  
  storage :file
  
  
  
  def store_dir
  
      "upload/path/"
  
  end
  
  
  
  process encode_video: [{ bunch of video options}]
  
  
  
  version :thumb do
  
      process thumbnail: [{ bunch of thumbnailer options }]
  
      def full_filename for_file
  
          png_name for_file, version_name
  
      end  
  
  end
  
  
  
  def png_name for_file, version_name
  
      %Q{#{version_name}_#{for_file.chomp(File.extname(for_file))}.png}
  
  end

  Now it's really just the same, except it's using storage :aws instead.

• FFMPEG How to insert short video and audio in longer video in specific time, size and position

  24 novembre 2020, par Milos Dimitrijevic

  FFMPEG How to insert short video (4sec) in longer video in specific time (from 15th to 19th second) and specific size. Long video is 1920x1080px and inserted video should be 1720x820px, positioned in the middle ?

  


  file info..
Duration : 00:00:22.07, start : 0.000000, bitrate : 3982 kb/s
Stream #0:0(und) : Video : h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 3900 kb/s, 29 fps, 29 tbr, 14848 tbn, 58 tbc (default)
Metadata :
handler_name : VideoHandler
Stream #0:1(und) : Audio : aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default)
Metadata :
handler_name : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'short.mp4' :
Metadata :
major_brand : mp42
minor_version : 19529854
compatible_brands : mp42isom
creation_time : 2020-10-25T11:01:10.000000Z
Duration : 00:00:03.02, start : 0.000000, bitrate : 14405 kb/s
Stream #1:0(eng) : Audio : aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 319 kb/s (default)
Metadata :
creation_time : 2020-10-25T11:01:10.000000Z
handler_name : Sound Media Handler
Stream #1:1(eng) : Video : h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 14078 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
Metadata :
creation_time : 2020-10-25T11:01:10.000000Z
handler_name : Video Media Handler
encoder : AVC Coding