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• How to dump RTSP to raw data file without encoding

  28 juin 2020, par Yves

  I've read this link : How to dump raw RTSP stream to file ?

  


  In this link, it seems that dumping RTSP stream to some formatted file, such as mp4, is normal.

  


  But I want to store the RTSP stream into the raw data files, instead of files like mp4, avi etc. And I should be able to extract data from the raw data files and send it out as RTSP stream too.

  


  In a word, this is what I need :

  


  

  1. receiving RTSP stream ---> 2. store RTSP data into raw data files ---> 3. read raw data files and send data as RTSP stream

  


  


  Why do I need this ?

  


  Because as my understanding, storing RTSP strema into some formatted file, such as mp4, needs to do an action of encoding (encode RTSP to mp4). But for me, I don't need this action, I simply need to store RTSP data and re-send it as RTSP stream. So if I can store RTSP into the raw-data file, instead of mp4, I don't need to spend computer resources on the action of encoding.

  


• How can I programmatically write and read random video watermarks ?

  13 novembre 2017, par GreenTriangle

  I spent a few minutes trying to think of a clearer way to word my title, but I couldn’t manage it, sorry.

  I want to essentially canary trap video files : I am (hypothetically, this is not real but a personal exercise) offering them up to 5,000 different people, and if one gets leaked, I want to know who leaked it. Metadata is too easily emoved, so what I’d like to do is add a random and subtle watermark to each file, and store information about that in a database.

  For example : on Joe Smith’s copy, a 10x10 pixel 80% transparent red square in the upper left corner for 5 frames. On Diane Brown’s copy, a full-width 5-pixel 90% transparent black bar on the bottom edge for 15 frames. Then, if I find a leaked copy, I could check it against the database.

  I know this still isn’t foolproof : cropping would break co-ordinates, hue/brightness transforms would break colour reading, cutting time would break timestamps. But if I did want to do this anyway, what would be a good strategy for it ?

  My idea was to generate PNG overlays randomly, split the video into parts with mkvtoolnix/ffmpeg, re-encode the middle part with ffmpeg + overlay filter, and then rejoin them. But is this silly when there’s a "proper" way to do it ? And what would I be doing to read the watermarks, which I can’t even really conceive of ?

• Gujarati text properly not show on output video using FFmpeg Library in Android

  15 mars 2024, par sanjay dangar

  Gujarati text overly on video using FFmpeg Library on Android

  


  below my code in Gujarati text twin word proper does not show

  


  I am Enter this text ="વડાપ્રધાનશ્રી નરેન્દ્રભાઇ મોદી." but output video in proper not show

  


   fun addFrame2VideoEditFun(&#xA;        videoPath: String,&#xA;        fontPath: String,&#xA;        outputPath: String&#xA;    ): Array<string> {&#xA;        val inputs: ArrayList<string> = ArrayList()&#xA;     var textFile = "વડાપ્રધાનશ્રી નરેન્દ્રભાઇ મોદી."&#xA;        inputs.apply {&#xA;            add("-i")&#xA;            add(videoPath)&#xA;            add("-vf")&#xA;            add("drawtext=fontfile=$fontPath:text=$textFile:fontsize=24:fontcolor=white:x=(w-text_w)/2:y=h-line_h")&#xA;            add("-c:a")&#xA;            add("copy")&#xA;            add(outputPath)&#xA;        }&#xA;        return inputs.toArray(arrayOfNulls(inputs.size))&#xA;    }&#xA;</string></string>

  


  my output video in below text show

  


  

  


  Gujarati text properly does not show on output video using FFmpeg Library.