Recherche avancée

Sur d’autres sites (4688)

• Rails 5 - Concurrent large Video uploads using Carrierwave eats up the server memory/space

  22 mars 2020, par Milind

  I have a working Rails 5 apps using Reactjs for frontend and React dropzone uploader to upload video files using carrierwave.

  So far, what is working great is listed below -

  1. User can upload videos and videos are encoded based on the selection made by user - HLS or MPEG-DASH for online streaming.
  2. Once the video is uploaded on the server, it starts streaming it by :-
     • FIRST,copying video on /tmp folder.
     • Running a bash script that uses ffmpeg to transcode uploaded video using predefined commands to produce new fragments of videos inside /tmp folder.
     • Once the background job is done, all the videos are uploaded on AWS S3, which is how the default carrierwave works
  3. So, when multiple videos are uploaded, they are all copied in /tmp folder and then transcoded and eventually uploaded to S3.

  My questions, where i am looking some help are listed below -

  1- The above process is good for small videos, BUT what if there are many concurrent users uploading 2GB of videos ? I know this will kill my server as my /tmp folder will keep on increasing and consume all the memory, making it to die hard.How can I allow concurrent videos to upload videos without effecting my server’s memory consumption ?

  2- Is there a way where I can directly upload the videos on AWS-S3 first, and then use one more proxy server/child application to encode videos from S3, download it to the child server, convert it and again upload it to the destination ? but this is almost the same but doing it on cloud, where memory consumption can be on-demand but will be not cost-effective.

  3- Is there some easy and cost-effective way by which I can upload large videos, transcode them and upload it to AWS S3, without effecting my server memory. Am i missing some technical architecture here.

  4- How Youtube/Netflix works, I know they do the same thing in a smart way but can someone help me to improve this ?

  Thanks in advance.

• ffmpeg won't execute properly in google app engine standard nodejs

  3 septembre 2019, par tommyc38

  I have tried for three full days to get GAE (standard - nodejs) to run a simple video transcoder from MOV to MP4 using ffmpeg. I have tried using ffluent-ffmpeg, kicking off a child process (e.g. spawn), and nothing works. As soon as it hits the call to the executable it always errors. I have confirmed ffmpeg is installed and even tried using ffmpeg-static. Moreover, I have it working on my local machine with no problems (using all of the aforementioned ways).

  I have also tried logging the errors and nothing is really all that helpful. I can see its working through any installed package including ffmpeg (system package).

  Below is the pseudo code...step three is where the problem occurs.

  1. Send file name to GAE endpoint
  2. Download the file from google cloud storage to a temp file
  3. Transcode using ffmpeg
  4. Upload temp file to google cloud storage
  5. Remove old google cloud storage file
  6. Remove temp file

  The file I am using to test is 6MB...a 5 second video I took on my iPhone. Thank you in advance.

  UPDATE : I successfully deployed the exact same code to Node Flex environment and everything works great. I wasn’t able to get any errors in the standard environment that directed me where to look but my guess is it has something to do with how it stores the file I pipe into FFMPEG on GAE Node Standard. The docs say its a virtual file system that uses RAM. I’d love to hear if anybody managed to get it working in the standard environment.

• iOS switching between audio & subtitle tracks added using ffmpeg

  27 décembre 2019, par Tony M

  Edit : Title altered to reflect that the answer and comments by @llogan cover switching between both audio and subtitle tracks.

  I have an m.mp4 with English audio and want to add a second audio stream in Italian so that I can play either language using the iPhone. When I used this command :

  ffmpeg -i m.mp4 -i ita.mp3 -c copy -map 0 -map 1 out.mp4 

  the output from ffmpeg -i out.mp4 (see below) shows that a new audio stream is added, and I can switch between audio streams using the VLC player. Yet when I transfer the video to the TV app and play it on either MacOS or iOS it only plays the original English and I see no options to play other languages.

  How do I get it to be able to switch between either audio on iOS ?

  Here is the output from ffmpeg -i out.mp4:

      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 400x300 [SAR 1:1 DAR 4:3], q=2-31, 482 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 24k tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 102 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler
  
      Stream #0:2: Audio: mp3 (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 152 kb/s
  
      Metadata:
  
        encoder         : LAME3.100
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
    Stream #1:0 -> #0:2 (copy)