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• How do I independently fade in/out multiple (3+) overlay images over video using FFMPEG ?

  3 mars 2017, par blahblahber

  Using an arbitrary source video, I would like to INDEPENDENTLY fade in/fade out a minimum of three .png overlays/watermarks at various times throughout the video. I’m having trouble getting the syntax right for the filter chain.

  In these failed attempts below, I’m using four transparent .png images all at 1920x1080 using the same sized source input video. No scaling/positioning needed, just the overlays fading in and out at the defined times.

  I have the functionality working without fade, unsing ’enable’, like so :

  ffmpeg -i vid1.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
  "overlay=0:0:enable='between(t,8,11)' [tmp];
  
  [tmp]overlay=0:0:enable='between(t,10,15)'[tmp1];
  
  [tmp1]overlay=0:0:enable='between(t,15,138)'[tmp2];
  
  [tmp2]overlay=0:0:enable='between(t,140,150)" 
  
  -c:v libx264 -c:a copy 
  
  -flags +global_header -shortest -s 1920x1080 -y out.mp4

  I just want the same control, using fade in/out.

  The following almost works as I’d like but I obviously don’t want the entire output stream to fade out. I realize that adding the fade=out to lines 7, 8 & 9 is fading the combined output (starting at line 7), but this is as close as I’ve come where I see each overlay image actually fading. The defined fades in lines 3, 4 and 5 apparently don’t affect anything, and that’s where I defined them originally. When I copied them to the output stream, the fade works on each overlay image, but again I don’t want it to affect the entire output stream, just the individual overlays.

  ffmpeg -i vid1.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
      "[1:v]fade=out:st=3:d=1[watermark0]; 
  
      [2:v]fade=out:st=4:d=1[watermark1]; 
  
      [3:v]fade=out:st=5:d=1[watermark2]; 
  
      [4:v]fade=out:st=6:d=1[watermark3]; 
  
      [0:v][watermark0] overlay=0:0 [tmp0]; 
  
      [tmp0][watermark1] overlay=0:0,fade=out:st=4:d=1 [tmp1]; 
  
      [tmp1][watermark2] overlay=0:0,fade=out:st=6:d=1 [tmp2]; 
  
      [tmp2][watermark3] overlay=0:0,fade=out:st=8:d=1 [out]" -map "[out]" -c:v libx264 -c:a copy 
  
      -flags +global_header -shortest -s 1920x1080 -y out.mp4

  I’ve also tried ’split’ with similar results to the above, but the fade only seems to work on the first image (this one uses fade in as well) :

  ffmpeg -i vid.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
  "[1:v]split=4[wm1][wm2][wm3][wm4]; 
  
  [wm1]fade=in:st=1:d=1:alpha=1,fade=out:st=3:d=1:alpha=1[ovr1]; 
  
  [wm2]fade=in:st=2:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[ovr2]; 
  
  [wm3]fade=in:st=3:d=1:alpha=1,fade=out:st=5:d=1:alpha=1[ovr3]; 
  
  [wm4]fade=in:st=4:d=1:alpha=1,fade=out:st=6:d=1:alpha=1[ovr4]; 
  
  [0:v][ovr1]overlay=0:0[base1]; 
  
  [base1][ovr2]overlay=0:0[base2]; 
  
  [base2][ovr3]overlay=0:0[base3]; 
  
  [base3][ovr4]overlay=0:0[out]" -map "[out]" 
  
  -t 10 -c:v libx264 -c:a copy -flags +global_header -shortest -s 1920x1080 -y out.mp4

  Any help is greatly appreciated ! :)

• It’s January 28th : Let’s celebrate Data Privacy !

  29 janvier 2018, par Matomo Core Team

  It is a special Sunday here for us at Matomo, as today is international Data Privacy Day. The day was created in 2007 to raise awareness of the importance of data privacy for people and businesses worldwide.

  

  What is data privacy about ?

  Personal data refers to any data which is collected and can be linked to an individual human being such as phone records, credit card transactions, GPS position, IP addresses, browsing history… So basically, personal data refers to your identity online. That is why you should be highly concerned about sending your personal data (or your customers’ personal data) away. It is important to be aware of who is collecting the information and how it is being used.

  What big changes are happening in 2018 ?

  New privacy regulations GDPR comes into play next May 2018 : GDPR will bring about some changes (in the right direction) by making people and businesses aware of what data privacy means, and what they should be doing to protect their customers’ privacy. With these new regulations, data privacy awareness is reaching a critical milestone this year.

  How can I protect my privacy ?

  Here are a few tips to protect your privacy :

  • Educate yourself on the importance of privacy : the more informed you are the better.
  • Use open source solutions where you can keep full control of your own data (such as NextCloud instead of Dropbox and of course Matomo instead of Google Analytics),
  • Experiment with different online services to protect your data privacy, for example using an alternative search engine (such as DuckDuckGo instead of Google) or an alternative email provider (such as ProtonMail).

  What’s coming next for Matomo and Privacy ?

  Here at Matomo, we are building the leading decentralised open web analytics platform. We’re currently working on new sets of privacy features to make compliance with GDPR a breeze. Stay tuned here to be notified when we launch the new privacy compliance tools !

  And in case you’ve missed this important info, you may be interested in :

  • Configure Privacy Settings in Matomo
  • 11 ways Matomo Analytics helps you to protect your visitors privacy

   

  The post It’s January 28th : Let’s celebrate Data Privacy ! appeared first on Analytics Platform - Matomo.

• Encoding raw YUV420P to h264 with AVCodec on iOS

  4 janvier 2013, par Wade

  I am trying to encode a single YUV420P image gathered from a CMSampleBuffer to an AVPacket so that I can send h264 video over the network with RTMP.

  The posted code example seems to work as avcodec_encode_video2 returns 0 (Success) however got_output is also 0 (AVPacket is empty).

  Does anyone have any experience with encoding video on iOS devices that might know what I am doing wrong ?

  - (void) captureOutput:(AVCaptureOutput *)captureOutput
  
   didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
  
          fromConnection:(AVCaptureConnection *)connection {
  
  
  
    // sampleBuffer now contains an individual frame of raw video frames
  
    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
  
  
  
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
  
  
  
    // access the data
  
    int width = CVPixelBufferGetWidth(pixelBuffer);
  
    int height = CVPixelBufferGetHeight(pixelBuffer);
  
    int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
  
    unsigned char *rawPixelBase = (unsigned char *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
  
  
  
  
  
    // Convert the raw pixel base to h.264 format
  
    AVCodec *codec = 0;
  
    AVCodecContext *context = 0;
  
    AVFrame *frame = 0;
  
    AVPacket packet;
  
  
  
    //avcodec_init();
  
    avcodec_register_all();
  
    codec = avcodec_find_encoder(AV_CODEC_ID_H264);
  
  
  
    if (codec == 0) {
  
      NSLog(@"Codec not found!!");
  
      return;
  
    }
  
  
  
    context = avcodec_alloc_context3(codec);
  
  
  
    if (!context) {
  
      NSLog(@"Context no bueno.");
  
      return;
  
    }
  
  
  
    // Bit rate
  
    context->bit_rate = 400000; // HARD CODE
  
    context->bit_rate_tolerance = 10;
  
    // Resolution
  
    context->width = width;
  
    context->height = height;
  
    // Frames Per Second
  
    context->time_base = (AVRational) {1,25};
  
    context->gop_size = 1;
  
    //context->max_b_frames = 1;
  
    context->pix_fmt = PIX_FMT_YUV420P;
  
  
  
    // Open the codec
  
    if (avcodec_open2(context, codec, 0) < 0) {
  
      NSLog(@"Unable to open codec");
  
      return;
  
    }
  
  
  
  
  
    // Create the frame
  
    frame = avcodec_alloc_frame();
  
    if (!frame) {
  
      NSLog(@"Unable to alloc frame");
  
      return;
  
    }
  
    frame->format = context->pix_fmt;
  
    frame->width = context->width;
  
    frame->height = context->height;
  
  
  
  
  
    avpicture_fill((AVPicture *) frame, rawPixelBase, context->pix_fmt, frame->width, frame->height);
  
  
  
    int got_output = 0;
  
    av_init_packet(&packet);
  
    avcodec_encode_video2(context, &packet, frame, &got_output)
  
  
  
    // Unlock the pixel data
  
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
  
    // Send the data over the network
  
    [self uploadData:[NSData dataWithBytes:packet.data length:packet.size] toRTMP:self.rtmp_OutVideoStream];
  
  }

  Note : It is known that this code has memory leaks because I am not freeing the memory that is dynamically allocated.

  UPDATE

  I updated my code to use @pogorskiy method. I only try to upload the frame if got output returns 1 and clear the buffer once I am done encoding video frames.