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• vf_colorspace : Interpret unspecified color range as limited range

  19 septembre 2016, par Vittorio Giovara

  vf_colorspace : Interpret unspecified color range as limited range
  This is the assumption that is made in pixel format conversion do
  
  throughout the code (in particular swscale), and BT-specifications
  
  mandate.
  Add a warning to inform the user that an automatic selection is being
  
  made.
  Signed-off-by : Vittorio Giovara <vittorio.giovara@gmail.com>
  
  Signed-off-by : Ronald S. Bultje <rsbultje@gmail.com>
  

  • [DH] libavfilter/vf_colorspace.c

• Android FFmpeg export of the Video in SurfaceView with Pinch/Scale/Zoom/Bg Color Operation

  31 mai 2024, par CoderDev

  I'm working on a feature in which I need to perform some actions on the selected video from the gallery and then upload it on the Backend server, on this selected video I can pinch it to scale up/down/zoom in/out and place it anywhere on the screen (even out side the screen), just like the Instagram app.
I can apply a background color which will be applied to the whole space of the outer of the video frame.

  


  After all the above changes I'm exporting the changes to the output video that will contain all the changes that I've mentioned above. I'm using the FFMpeg for the same :

  


      implementation("com.arthenica:ffmpeg-kit-full-gpl:6.0-2.LTS")



  


  Basically the operation is being achieved with this solution (Except Export Video) : Android SurfaceView operation on Video to Pinch/Scale/Zoom/Bg Color

  


  I've tried numerous FFmpeg commands but not getting the adequate output, I've tried below solution :

  


      private fun exportVideo() {
        val outputVideoPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).path + "/ffmpegoutput.mp4"
        val inputVideoPath = selectedFilePath
        val bgColor = getColorHexCode()

        // Load the input video dimensions
        val retriever = MediaMetadataRetriever()
        retriever.setDataSource(inputVideoPath)
        val videoWidth = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH)?.toInt() ?: 0
        val videoHeight = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT)?.toInt() ?: 0
        retriever.release()

        // Calculate the scaled dimensions
        val scaledWidth = (videoWidth * scaleFactor).toInt()
        val scaledHeight = (videoHeight * scaleFactor).toInt()

        // Calculate the new translation
        val translatedX = translationX.toInt()
        val translatedY = translationY.toInt()

         // Ensure the output dimensions are at least as large as the scaled dimensions
        val outputWidth = maxOf(deviceWidth, scaledWidth + abs(translatedX) * 2)
        val outputHeight = maxOf(deviceHeight, scaledHeight + abs(translatedY) * 2)

        // Calculate padding positions
        val xPad = (outputWidth - scaledWidth) / 2 + translatedX
        val yPad = (outputHeight - scaledHeight) / 2 + translatedY

        // Create the filter string for FFmpeg
        val filter = "scale=$scaledWidth:$scaledHeight," +
                "pad=$diagonal:$diagonal:(ow-iw)/2:(oh-ih)/2:$bgColor," +
                "pad=$outputWidth:$outputHeight:$xPad:$yPad:$bgColor"


        val command = ("-i $inputVideoPath " +
                "-vf $filter " +
                "-c:a copy " + // Copy the audio stream without re-encoding
                "-y $outputVideoPath"
                )

        // Execute FFMPEG command
        executeFFmpegKitCommand(command)
    }


    private fun executeFFmpegKitCommand(command: String) {
        FFmpegKit.executeAsync(command) { session ->
            println("FFMPEG executeAsync, session: $session")
            val returnCode = session.returnCode
            if (returnCode.isValueSuccess) {
                // Handle success
                runOnUiThread {
                    Toast.makeText(this, "Video saved successfully!", Toast.LENGTH_SHORT).show()
                }
            } else {
                // Handle failure
                runOnUiThread {
                    Toast.makeText(this, "Failed to save video", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }


  


  But this not giving me the adequate output, it's not creating the output with the Screen's height/width (Tried passing the same), and the original video position is also not correct on the canvas which I've placed with the touch event.

  


• AV_PIX_FMT_NV12 says it has a 12bpp bit pixel color but data is uint8_t how can I modify the pixels from a frame ?

  9 juillet 2024, par user14290993

  The documentaions says AV_PIX_FMT_NV12 planar YUV 4:2:0, 12bpp, 1 plane for Y and 1 plane for the UV components, which are interleaved (first byte U and the following byte V)

  


  also linesize[1] and linesize[0] are 1920, but if I strlen(data[1]) ( UV components )
I get 1044587 this divided by the frame->heigth gives me 967,21... so the linesize is wrong ?