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• Merging .flv chunks from stream site

  4 décembre 2016, par Iztooi

  I’m trying to download a video from an alternative version of the Ustream site. This site is apparently used for a DRM protection, in fact you can’t watch this video without having access to it through a login from this site.
  The video system should be the same used by ustream (same links), that is calling different flv chunks every x seconds and merging them into the stream (similar to an rtmp service, but it doesn’t use this protocol).

  I managed to download every .flv chunks composing this video, but i had issues on merging them into a single file. First of all these flvs files have some audio/video lags/problems, but since there is no other way to download this video i’m not complaining about lags.

  The real issue is that every flv file has an additive increase on the duration, despite having a normal size. Video duration is about 6 seconds, so the first chunk is 6 seconds long, the second chunk is 12 seconds long, although only the first 6 are visible (the remaining 6 are "corrupted"). If i try to merge (with ffmpeg or any video-joining software) all these files (about 600-700, for a total duration of 1 hour and 15 minutes) only the first two sections are visible, then I cannot see anything. (Being more clear, if i try to merge the first 2 chunks, file is 18 seconds long and i can see the first 12 ; if i try to merge the first 3 chunks, file is 36 seconds long and i can still only see the first 12 seconds.)

  Anyone has any idea ?

• mp4 And Rotation - Remove Flags But Set Rotation

  7 avril 2024, par Bud

  I'm having a hard time with the rotation on some mp4 files I have. It may well be my poor understanding, so forgive me if I set out what I know (or think I know) and then what I want to happen.

  


  An mp4 has, obviously, a right way up - that is, the way you want it to show when you watch it. Call this the orientation. This isn't metadata - it's just the way you, as a person, want to see the image, with people's heads at the top of the screen and their feet at the bottom.

  


  As part of the metadata, mp4 files have a value/parameter (I believe called 'rotate') that tells how much the mp4 needs to be rotated (0, 90, 180, 270 degrees) so that it is correctly oriented. This value/parameter is observed by some players and not by some others. So if I play my video using this player, all is good (because it observes the value/parameter) - but if I play it with that other player, everything is sideways (because it doesn't observe the value/parameter).

  


  What I want to do is orient the mp4 correctly with the value/parameter set to 0, so that no matter what player plays it, it will always be played oriented correctly (because those players that observe the value/parameter will see it's 0 and do nothing). So I think what I need to do is somehow remove the value/parameter, then rotate the mp4 to the correct orientation without using the rotate value/parameter. I'm thinking of something like what FastStone Image Viewer can do with JPGs - rotate them losslessly without setting the rotate value.

  


  I've used ffmpeg and believe that it removed the rotate value/parameter (or set it to 0) because after I used it, suddenly my video appeared sideways in Windows Explorer, where previously it had appeared right way up. But how do I now rotate it to the correct orientation without changing the rotate value/parameter ?

  


  Sorry, this is very long winded and confused. Just like me.

  


• qt faststart and ffmpeg to generate a live mp4 file [duplicate]

  27 février 2014, par Dnaso

  This question already has an answer here :

  • Live video streaming using progressive download (and not RTMP) in Flash
    
    2 answers
    

  I am using ffmpeg to create an mp4 file on my server. I am also trying to use qt fast start to be able to move the moov atom to the front so it will stream. I have searched all over the internet with no luck. Is it possible to put my video/audio in a mp4 buffer type file and then be able to play it while ffmpeg is still dumping video and audio data into the stream ? the point is I am trying to stream from a camera and Android is horrid... I know both ios and android support mp4 so I was trying to figure a way I can make my rtsp Mp4.

  main point of the story : I want to continuously feed my mp4 container my camera feed and still be able to playback the file os my clients can watch.

  any help appreciated thank you.