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• 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.

• ffserver : Add client requested urls to the status page

  29 novembre 2016, par Michael Niedermayer

  ffserver : Add client requested urls to the status page
  Fixes Ticket3791
  Reviewed-by : "Reynaldo H. Verdejo Pinochet" <reynaldo@osg.samsung.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] ffserver.c
  • [DH] tests/ffserver-regression.sh
  • [DH] tests/ffserver.regression.ref

• Android : mp4 file plays when downloaded but when choosing "Video" player gets "Cannot play video"

  11 juillet 2019, par gview

  I’ve converted the video to an mp4 with ffmpeg using the h264 codec and AAC, and used the baseline profile.

  Videos are 540x360x250kbps

  I then ran qt-faststart on the file to move the atoms into the right order.

  I’ve stuck the file up on a wiki we use and created a link to it.

  My test phone is a Samsung Galaxy S3.

  When I browse to the page that has links to the mp4’s on it, and I click on them, I get a popup window with 2 options : Internet and Video.

  If I download the videos using the "Internet" option, I can play them on the phone without issue.

  I’ve done other encodings with the main profile as well, and these also play fine. I thought that a powerful phone like the s3 would be able to handle the more advanced compression schemes available in h264, however I’ve also browsed the Android docs in regards to supported video formats, and it seems to state that only the "baseline" compression profile is supported.

  Regardless, what doesn’t work is trying to use the "Video" option which I assume tries to stream the video.

  For the wiki in question, clicking on the link reveals that the content-type and content-length headers are being set :

  Content-Length  6175996
  
  Content-Type    video/mp4;charset=UTF-8

  Clicking on the link with a browser invokes a player (Quicktime in most cases) that can play the mp4’s.

  Is there more to having the file HTTP streamable beyond making a link to it ? Why won’t my Android 4 play these files ?

  UPDATE :
  I decided to make a quick HTML5 page using the video tag, and the videos do play on both my Galaxy S3 and the latest IOS.