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• 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.

• Need help finding a way to use avconv or ffmpeg to convert any video to an exact size and shape

  29 octobre 2013, par mikecole79

  This is for work. We have a system that supports streaming video, but we support multiple players. I have multiple systems that I COULD use for this. Currently, I've been using the media server that we use to stream the video, which has ffmpeg on it (running Red Hat 4). On that system, I've used :

   ffmpeg -i INPUT_FILE.mp4 -c:v libx264 -crf 23 -maxrate 3000k -bufsize 30000k -c:a aac -strict experimental -b:a 192k -filter:v "scale=iw*min($width/iw\,$height/ih):ih*min($width/iw\,$height/ih), pad=$width:$height:($width-iw*min($width/iw\,$height/ih))/2:($height-ih*min($width/iw\,$height/ih))/2" -f OUTPUT_FILE.mp4

  And I thought that it worked well. On one file I used to test, it seemed to display properly on both player types. On a different file, it did not appear properly. The input files are also in varying formats (mostly mp4, with a few m4g files) and different aspect ratios.

  We also have many desktop/laptop machines that are running Ubuntu 13.04 (comes with avconv) that I'd like to be able to use to format video as well. If I can get at least one of these systems to properly format video, that would be great, but ideally I'd like to figure out how to do this with both avconv AND ffmpeg so I can use any system.

  The problem that we're trying to solve is that one player is an Android DMP device, which will play a video of varying sizes properly by adding black bars at the sides or top/bottom as needed to keep the video sized properly. The other player is a Samsung Smart TV, which is SO Smart that it can reformat videos to fit the screen. Which sucks horribly, because if they're not sized to exactly the right format, it will stretch them one direction or another to make them be sized right. The resulting video show's people that appear to be 8 feet tall weighing 130 pounds, or 4 feet tall and 3 feet wide.

  Obviously, this isn't what we desire, but I lack the knowledge of avconv/ffmpeg to do anything to fix it. I need an expert, and I am not he. Nor is anyone I currently work with an expert on this subject. Anyone that is, I'd appreciate your help more than I can express via a web interface.

  Thanks !

• How to handle differing .mp4 file types from different sources ?

  10 octobre 2017, par Dave502619

  If I take a .mp4 recorded on my mobile (Samsung S5) and pass it through FFmpeg with the below command, the output file (fileX.avi) is a greyscale bitmap uncompressed video file.

  • The offset values in fileX.avi (output from FFmpeg) to allow me to locate the video frame data are always 5680 bytes for the file header.

  • And 62 bytes for the inter frame header.

  • The data is uncompressed RGB24 so i can easily calculate the size of a video frame from height x width x 3.

  So my C# application can access the video frames in fileX.avi always at these above offsets.
  (This works great).

  My FFmpeg Command is :

  ffmpeg.exe -i source.mp4 -b 1150 -r 20.97 -g 120 -an -vf format=gray -f rawvideo -pixfmt gray -s 384x216 -vcodec rawvideo -y fileX.avi

  However... I recently took an .mp4 file from a different source (produced by Power Director 14 instead of direct from my mobile phone) and used this as the input source.mp4. But now the structure of fileX.avi differs as the offset values of 5680 + 62 bytes from the start in fileX.avi do not land me at the start of the video data frames.

  There seems to be different file formats for .mp4 - and obviously if there are my crude offset approach will not work for them all. I suspected at the time I wrote the code my method was all too easy a solution !

  So can anyone advise on the approach I should take now ? Should I check the original .mp4 or the output file (fileX.avi) to determine a "file type" to which I can determine the different offsets ?

  At the very least I need to be able to identify the "type" of .mp4 file that works so I can declare the type that will work with my software.