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• lavc/qsvdec : Use coded_w/h for frame resolution when use system memory

  20 mai 2024, par Fei Wang

  lavc/qsvdec : Use coded_w/h for frame resolution when use system memory
  Fix output mismatch when decode clip with crop(conf_win_*offset in
  
  syntax) info by using system memory :
  $ ffmpeg -c:v hevc_qsv -i conf_win_offet.bit -y out.yuv
  Signed-off-by : Fei Wang <fei.w.wang@intel.com>
  

  • [DH] libavcodec/qsvdec.c

• FFMPEG in Android Kotlin - processed video should have specific resolution

  31 mai 2024, par Utsav

  I'm recording video from both the front and back cameras and I get a PIP video and a horizontal stacked video. I need to merge both videos after that. The problem with merging is that it requires both the videos (PIP and stacked) to have the same resolution and aspect ratio. This is not the case. So the FFMPEG command being executed in code to generate both these videos needs to be modified to make the resolution and aspect ratio the same.

  


  //app -> build.gradle
implementation "com.writingminds:FFmpegAndroid:0.3.2"


  


      private fun connectFfmPeg() {
        val overlayX = 10
        val overlayY = 10
        val overlayWidth = 200
        val overlayHeight = 350

        outputFile1 = createVideoPath().absolutePath
        outputFile2 = createVideoPath().absolutePath
        //Command to generate PIP video
        val cmd1 = arrayOf(
            "-y",
            "-i",
            videoPath1,
            "-i",
            videoPath2,
            "-filter_complex",
            "[1:v]scale=$overlayWidth:$overlayHeight [pip]; [0:v][pip] overlay=$overlayX:$overlayY",
            "-preset",
            "ultrafast",
            outputFile1
        )

        //Command to generate horizontal stack video
        val cmd2 = arrayOf(
            "-y",
            "-i",
            videoPath1,
            "-i",
            videoPath2,
            "-filter_complex",
            "hstack",
            "-preset",
            "ultrafast",
            outputFile2
        )

        val ffmpeg = FFmpeg.getInstance(this)
        //Both commands are executed
        //Following execution code is OK
        //Omitted for brevity
    }


  


  Here is mergeVideos() executed lastly.

  


      private fun mergeVideos(ffmpeg: FFmpeg) {
        //Sample command:
        /*
        ffmpeg -y -i output_a.mp4 -i output_b.mp4 \
        -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" \
        -map "[outv]" -map "[outa]" -preset "ultrafast" output.mp4
        */
        finalOutputFile = createVideoPath().absolutePath

        val cmd = arrayOf(
            "-y",
            "-i",
            outputFile1,
            "-i",
            outputFile2,
            "-filter_complex",
            "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]",
            "-map", "[outv]",
            "-map", "[outa]",
            "-preset", "ultrafast",
            finalOutputFile
        )
        //Execution code omitted for brevity
}


  


  Error : Upon execution of mergeVideos(), there is no progress or failure method called. The Logcat stays where it is and the app does not crash either.

  


  Possible solution :
Once I got the generated PIP and horizontal stacked videos to my device's local storage, I tried out some FFMPEG commands on the prompt to process them after moving them to my laptop and it works on the command line :

  


  //First two commands can't be executed in Kotlin code
//This is the main problem
ffmpeg -i v1.mp4 -vf "scale=640:640,setdar=1:1" output_a.mp4
ffmpeg -i v2.mp4 -vf "scale=640:640,setdar=1:1" output_b.mp4
ffmpeg -y -i output_a.mp4 -i output_b.mp4 -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" -preset "ultrafast" output.mp4
//Merge is successful via command prompt


  


  Please suggest a solution

  


• Output resolution substantially below input resolution [closed]

  29 août 2024, par bobford

  I have written an Android app to overlay a watermark png using FFMpeg 6.0 which works fine on 1k and 4k videos. In both cases the output resolution substantially deteriorates albeit consistent with the reduction in file size. In both cases, the original width-height pixel sizes are retained.

  


  The ffmpeg command is :

  


  String[] array = new String[] {"-i ", inputFile, " -i ", watermarkFile, " -filter_complex ", overlayPosition, " -codec:a copy ", outputFile};
String delimiter = "";
String command = String.join(delimiter, array);


  


  I would like to retain the original resolution, or as close as possible, even with the larger file size.
It would seem there are default parameters which I am unaware of, and have absolutely no idea of how to find them, even after extensive searching. Thank you for your help !