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• Upload video and convert to MPEG-DASH [on hold]

  26 juin 2018, par Justin Rec

  Upload video and convert to MPEG-DASH I’m doing ...

  Upload file
  
  1. move_uploaded_file($_FILES['video']['tmp_name'], video.mp4);
  
  
  
  Converting video
  
  2.  ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 3000k -maxrate 3000k -bufsize 1500k -vf "scale=-1:1080" video_1080.mp4
  
      ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 1500k -maxrate 1500k -bufsize 1000k -vf "scale=-1:720"  video_720.mp4
  
      ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 500k  -maxrate 500k  -bufsize 500k  -vf "scale=-1:480"  video_480.mp4
  
  
  
  From mp4 to MPEG-DASH
  
  3. MP4Box -dash 4000 -frag 4000 -rap -segment-name %s/segment_ -url-template -out manifest.mpd video_1080.mp4 video_720.mp4 video_480.mp4
  
  
  
  Delete mp4 videos
  
  4.  unlink('video_1080.mp4');
  
      unlink('video_720.mp4');
  
      unlink('video_480.mp4');

  Everything is working. But I’m not sure that this is the right decision. Is there a better solution ? Do I do everything right ?

• Developers and vendors : Want a Matomo Hoodie ? Add a tag to the Matomo Open Source Tag Manager and this could be yours !

  7 juin 2018, par Matomo Core Team — Community, Development

  The Free Open Source Tag Manager is now available as a public beta on the Matomo Marketplace. Don’t know what a Tag Manager is ? Learn more here. In Short : It lets you easily manage all your third party JavaScript and HTML snippets (analytics, ads, social media, remarketing, affiliates, etc) through a single interface.

  Over the last few months we have worked on building the core for the Matomo Tag Manager which comes with a great set of features and a large set of pre-configured triggers and variables. However, we currently lack tags.

  This is where we need your help ! Together we can build a complete and industry leading open source tag manager.

  Tag examples include Google AdWords Conversion Tracking, Facebook Buttons, Facebook Pixels, Twitter Universal Website Tags, LinkedIn Insights.

  Are you a developer who is familiar with JavaScript and keen on adding a tag ? Or are you a vendor ? Don’t be shy, we appreciate any tags, even analytics related :) We have documented how to develop a new tag here, which is quite easy and straightforward. You may also need to understand a tiny bit of PHP but you’ll likely be fine even if you don’t (here is an example PHP file and the related JS file).

  As we want to ship the Matomo Tag Manager with as many tags as possible out of the box, we appreciate any new tag additions as a pull request on https://github.com/matomo-org/tag-manager.

  We will send out “Matomo Contributor” stickers that cannot be purchased anywhere for every contributor who contributes a tag within the next 3 months. As for the top 3 contributors… you’ll receive a Matomo hoodie ! Simply send us an email at hello@matomo.org after your tag has been merged. If needed, a draw will decide who gets the hoodies.

  FYI : The Matomo Tag Manager is already prepared to be handled in different contexts and we may possibly generate containers for Android and iOS. If you are keen on building the official Matomo SDKs for any of these mobile platforms, please get in touch.

  

• C++ ffmpeg video missing frames and won't play in Quicktime

  5 décembre 2019, par Oliver Dain

  I wrote some C++ code that uses ffmpeg to encode a video. I’m having two strange issues :

  1. The final video is always missing 1 frame. That is, if I have it encode 10 frames the final video only has 9 (at least that’s what ffprobe -show_frames -pretty $VIDEO | grep -F '[FRAME]' | wc -l tells me.
  2. The final video plays fine in some players (mpv and vlc) but not in Quicktime. Quicktime just shows a completely black screen.

  My code is roughly this (modified a bit to remove types that are unique to our code base) :

  First, I open the video file, write the headers and initialize things :

  template <class ptrt="ptrt">
  
  using UniquePtrWithDeleteFunction = std::unique_ptr>;
  
  
  
  
  
  std::unique_ptr<ffmpegencodingframesink> FfmpegEncodingFrameSink::Create(
  
      const std::string&amp; dest_url) {
  
    AVFormatContext* tmp_format_ctxt;
  
    auto alloc_format_res = avformat_alloc_output_context2(&amp;tmp_format_ctxt, nullptr, "mp4", dest_url.c_str());
  
    if (alloc_format_res &lt; 0) {
  
      throw FfmpegException("Error opening output file.");
  
    }
  
    auto format_ctxt = UniquePtrWithDeleteFunction<avformatcontext>(
  
        tmp_format_ctxt, CloseAvFormatContext);
  
  
  
    AVStream* out_stream_video = avformat_new_stream(format_ctxt.get(), nullptr);
  
    if (out_stream_video == nullptr) {
  
      throw FfmpegException("Could not create outputstream");
  
    }
  
  
  
    auto codec_context = GetCodecContext(options);
  
    out_stream_video->time_base = codec_context->time_base;
  
  
  
    auto ret = avcodec_parameters_from_context(out_stream_video->codecpar, codec_context.get());
  
    if (ret &lt; 0) {
  
      throw FfmpegException("Failed to copy encoder parameters to outputstream");
  
    }
  
  
  
    if (!(format_ctxt->oformat->flags &amp; AVFMT_NOFILE)) {
  
      ret = avio_open(&amp;format_ctxt->pb, dest_url.c_str(), AVIO_FLAG_WRITE);
  
      if (ret &lt; 0) {
  
        throw VideoDecodeException("Could not open output file: " + dest_url);
  
      }
  
    }
  
  
  
    ret = avformat_init_output(format_ctxt.get(), nullptr);
  
    if (ret &lt; 0) {
  
      throw FfmpegException("Unable to initialize the codec.");
  
    }
  
  
  
    ret = avformat_write_header(format_ctxt.get(), nullptr);
  
    if (ret &lt; 0) {
  
      throw FfmpegException("Error occurred writing format header");
  
    }
  
  
  
    return std::unique_ptr<ffmpegencodingframesink>(
  
        new FfmpegEncodingFrameSink(std::move(format_ctxt), std::move(codec_context)));
  
  }
  
  </ffmpegencodingframesink></avformatcontext></ffmpegencodingframesink></class>

  Then, every time I get a new frame to encode I pass it to this function (the frames are being decoded via ffmpeg from another mp4 file which Quicktime plays just fine) :

  // If frame == nullptr then we're done and we're just flushing the encoder
  
  // otherwise encode an actual frame
  
  void FfmpegEncodingFrameSink::EncodeAndWriteFrame(
  
      const AVFrame* frame) {
  
    auto ret = avcodec_send_frame(codec_ctxt_.get(), frame);
  
    if (ret < 0) {
  
      throw FfmpegException("Error encoding the frame.");
  
    }
  
  
  
    AVPacket enc_packet;
  
    enc_packet.data = nullptr;
  
    enc_packet.size = 0;
  
    av_init_packet(&enc_packet);
  
  
  
    do {
  
      ret = avcodec_receive_packet(codec_ctxt_.get(), &enc_packet);
  
      if (ret ==  AVERROR(EAGAIN)) {
  
        CHECK(frame != nullptr);
  
        break;
  
      } else if (ret ==  AVERROR_EOF) {
  
        CHECK(frame == nullptr);
  
        break;
  
      } else if (ret < 0) {
  
        throw FfmpegException("Error putting the encoded frame into the packet.");
  
      }
  
  
  
      assert(ret == 0);
  
      enc_packet.stream_index = 0;
  
  
  
      LOG(INFO) << "Writing packet to stream.";
  
      av_interleaved_write_frame(format_ctxt_.get(), &enc_packet);
  
      av_packet_unref(&enc_packet);
  
    } while (ret == 0);
  
  }

  Finally, in my destructor I close everything up like so :

  FfmpegEncodingFrameSink::~FfmpegEncodingFrameSink() {
  
    // Pass a nullptr to EncodeAndWriteFrame so it flushes the encoder
  
    EncodeAndWriteFrame(nullptr);
  
    // write mp4 trailer
  
    av_write_trailer(format_ctxt_.get());
  
  }

  If I run this passing n frames to EncodeAndWriteFrame line LOG(INFO) << "Writing packet to stream."; gets run n times indicating the n packets were written to the stream. But ffprobe always shows only n - 1 frames int he video. And the final video doesn’t play on quicktime.

  What am I doing wrong ??