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• FFmpeg : bitrate change dynamically

  13 avril 2012, par Kevin Yen-Fu Ou

  I read the previous thread and this is the response from NISHAnT,
  FFMPEG : Dynamic change of bit_rate for Video

   avcodec_init();
  
  
  
   avcodec_register_all();
  
  
  
   codec = avcodec_find_encoder(CODEC_ID_H263);
  
  
  
   c = avcodec_alloc_context();
  
  
  
   picture= avcodec_alloc_frame();
  
  
  
      c->bit_rate = bitrate;
  
      c->width = w;
  
      c->height = h;
  
      c->time_base= (AVRational){1,framerate};
  
      c->pix_fmt = PIX_FMT_YUV420P;
  
  
  
   avcodec_close(c);
  
  
  
   av_free(c);

  And this is my code :

      if(previous_BR != cur_BR){
  
          previous_BR = cur_BR;
  
  
  
          AVCodecContext* new_c = av_mallocz(sizeof(AVCodecContext));;
  
  
  
          avcodec_copy_context(new_c, ost_table[0]->st->codec);
  
  
  
  
  
          avcodec_close(ost_table[0]->st->codec);
  
          av_free(ost_table[0]->st->codec);
  
  
  
          avcodec_init();
  
          avcodec_register_all();
  
  
  
          ost_table[0]->enc = avcodec_find_encoder(CODEC_ID_H264);
  
          new_c = avcodec_alloc_context3(ost_table[0]->enc);
  
          ost_table[0]->st->codec = new_c;
  
  
  
          AVFrame *picture= avcodec_alloc_frame();
  
  
  
          new_c->bit_rate = cur_BR;
  
          new_c->width = 352;
  
          new_c->height = 288;
  
          int framerate = 30;
  
          new_c->time_base= (AVRational){1,framerate};
  
          new_c->pix_fmt = PIX_FMT_YUV420P;
  
          new_c->codec_type = AVMEDIA_TYPE_VIDEO;
  
          new_c->codec_id = CODEC_ID_H264;}

  ---

  I tried to add my code to transcode(), but ffmpeg exits after it goes through my codes.
  is there something wrong with my codes ?
  or what else I should add ?

  I put the code after "redo :", so that it will recursively loop back.
  please help !!

  Thank you.

• Introducing Matomo SEO Web Vitals

  13 septembre 2021, par Ben Erskine — About, Analytics Tips, Plugins

  SEO Web Vitals track your critical website performance metrics and are a core element of SEO best practice. 

  Start using Matomo SEO Web Vitals to monitor your website performance, optimise your visitor experience, improve your search result rankings, and see how your site compares to your competitors.

  

  What are SEO Web Vitals ?

  Web Vitals are made up of a number of important metrics, such as your website’s page speed and loading performance, these metrics all play an important role in search engine optimisation. 

  The more technical terms for these metrics are Page Speed Score, First Contentful Paint (FCP), Final Input Delay (FID), Last Contentful Paint (LCP) and Cumulative Layout Shift (CLS).

  Why should you use SEO Web Vitals ?

  SEO Web Vitals are being used more and more by search engines such as Google to rank websites so they help ensure a great page experience for users who arrive via links from their search results. 

  By monitoring your SEO Web Vitals you can see how good or bad a single page performs and then prioritise the optimisation of strategically important pages to help improve the ranking position within search engine results.

  For ease of use you can receive regular reports in your email inbox and you can configure custom alerts to automatically notify you when a page score changes significantly. This saves time by not having to check page performance scores manually while ensuring you will be notified should there be any important change that needs to be actioned.

  You should use SEO Web Vitals to understand how your site performance is impacting your overall visitor experience.

  Four key benefits of using SEO Web Vitals :

  Improve your search result rankings

  • SEO Web Vitals are a core element of SEO best practice and directly impact your search rankings.
  • Pages that load quickly and are more stable deliver a better user experience, so they’re ranked higher by search engines.

  Optimise your website visitor experience

  • Know how quickly pages on your website load to ensure you deliver an optimal visitor experience.
  • Identify page stability issues and implement the changes needed to enhance your visitor experience.

  Automate your website performance monitoring

  • Have peace of mind knowing if your metrics decrease, you can find and fix the root cause quickly.
  • Configure performance alerts and get automated reports sent to you.

  Incorporate website performance into your competitor analysis

  • These performance metrics are essentially open for anyone to inspect, so you can measure and benchmark your site against competitors. 

  How can I improve my SEO Web Vitals ?

  There are so many ways to improve these performance metrics, here are five of the common contributing factors.

  1. Your page speed score is a weighted average of your other performance metrics, so focus on improving the underlying metrics that contribute to this score.
  2. Ensure you use a high quality web host with an appropriate plan for your level of traffic to help improve your FCP time.
  3. Try removing large elements that aren’t required on your page to improve your LCP time.
  4. Optimise against Total Blocking Time to Improve your FID score.
  5. Consider using a Layout Shift Debugger to improve Your CLS Score

  Guide to Matomo SEO Web Vitals

  For more information and to learn how to configure SEO Web Vitals in Matomo, check out our full guide to SEO Web Vitals.

  You will learn :

  • What’s required to measure your SEO Web Vitals
  • How to configure SEO Web Vitals
  • How to analyse your SEO Web Vitals
  • How to understanding SEO Web Vitals metrics
  • How to analyse your page’s SEO Web Vitals over time
  • How to improve your SEO Web Vitals
  • How to monitor changes in your scores with custom alerts

  Need more resources ?

  Matomo Plugin SEO Web Vitals

  Matomo SEO Web Vitals FAQs

• Lossless ffmpeg conversion/encoding

  28 août 2021, par Marc Brown

  I'm looking for the best in quality when converting videos.

  



  I only want to use lossless audio and video encoders and a good container.

  



  How do I enable lossless x264 vcodec for ffmpeg ?

  



  I currently use ffmpeg -i "inputvideo" -s 1280x720 -ar 48000 -threads 4 -vcodec libx264 -acodec copy -dsur_mode 2 -ac 6 "outputvideo720p.mkv"

  



  I plan on using flac for the acodec by am unsure because I don't want to use quality if it switches to 16-bit instead of 24-bit