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• how to fix ffmpeg error 'frame crc mismatch'

  9 août 2013, par Sam

  I am trying to re-encode a video file using ffmpeg but every time I try to run it

  ffmpeg -i  -c:v libx264 -crf 25 -preset slow -c:a libfaac 

  it does the first five minutes or so of the video and then gives the following error and stops :

  frame CRC mismatch
  
  [matroska,webm @ 0x7ff609806600] Unknown entry 0x762F
  
  [matroska,webm @ 0x7ff609806600] Unknown entry 0x4B61
  
  [matroska,webm @ 0x7ff609806600] Unknown entry 0xA2
  
  [matroska,webm @ 0x7ff609806600] Unknown entry 0x7F38
  
  [matroska,webm @ 0x7ff609806600] Unknown entry 0x39E0B1
  
  frame= 7473 fps=8.3 q=30.0 size=   42488kB time=-577014:-32:-22.-77 bitrate=N/A 
  
  frame= 7473 fps=8.2 q=-1.0 Lsize=   43099kB time=00:05:12.06 bitrate=1131.4kbits/s    
  
  video:35549kB audio:7338kB subtitle:0 global headers:0kB muxing overhead 0.494802%
  
  [libx264 @ 0x7ff609826c00] frame I:70    Avg QP:21.35  size: 41968
  
  [libx264 @ 0x7ff609826c00] frame P:2000  Avg QP:24.37  size:  9139
  
  [libx264 @ 0x7ff609826c00] frame B:5403  Avg QP:26.21  size:  2811
  
  [libx264 @ 0x7ff609826c00] consecutive B-frames:  1.8%  2.7%  8.5% 87.1%
  
  [libx264 @ 0x7ff609826c00] mb I  I16..4: 25.7% 61.5% 12.8%
  
  [libx264 @ 0x7ff609826c00] mb P  I16..4:  5.3%  5.5%  0.5%  P16..4: 39.9%  6.3%  5.4%  0.0%  0.0%    skip:37.2%
  
  [libx264 @ 0x7ff609826c00] mb B  I16..4:  0.2%  0.4%  0.0%  B16..8: 36.6%  1.5%  0.2%  direct: 0.6%  skip:60.5%  L0:40.3% L1:58.3% BI: 1.3%
  
  [libx264 @ 0x7ff609826c00] 8x8 transform intra:52.6% inter:89.8%
  
  [libx264 @ 0x7ff609826c00] direct mvs  spatial:100.0% temporal:0.0%
  
  [libx264 @ 0x7ff609826c00] coded y,uvDC,uvAC intra: 38.4% 47.1% 8.5% inter: 6.5% 10.0% 0.0%
  
  [libx264 @ 0x7ff609826c00] i16 v,h,dc,p: 34% 18%  8% 39%
  
  [libx264 @ 0x7ff609826c00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 11%  7% 10% 10% 14% 13% 13% 11% 11%
  
  [libx264 @ 0x7ff609826c00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 16% 11%  6%  8% 13% 12% 12% 10% 12%
  
  [libx264 @ 0x7ff609826c00] i8c dc,h,v,p: 55% 21% 18%  6%
  
  [libx264 @ 0x7ff609826c00] Weighted P-Frames: Y:1.2% UV:0.9%
  
  [libx264 @ 0x7ff609826c00] ref P L0: 57.7% 10.2% 19.2%  5.9%  6.5%  0.5%  0.0%
  
  [libx264 @ 0x7ff609826c00] ref B L0: 82.1% 13.2%  3.6%  1.0%
  
  [libx264 @ 0x7ff609826c00] ref B L1: 94.8%  5.2%
  
  [libx264 @ 0x7ff609826c00] kb/s:934.32

  If I play the original video file in VLC, the frames at the point where the encoding stops go glitchy for a few seconds but then comes good again.

  How can I get around this ? I don't really mind if those few seconds stay glitchy (although it would be nice if that could be fixed) but I do need to re-encode this video, with or without the glitchy couple of seconds...

  Even if I use another program like iFlicks to try and re-encode it does up to the same point and then stops. It also stops at the same point if I use ffmpeg to copy the codecs into a new mp4 container.

• How to configure and validate a Funnel in Piwik Analytics

  16 janvier 2017, par InnoCraft — Community

  In the last blog post we have covered how the conversion Funnel plugin enriches your Piwik experience. This post will focus on how to configure and validate your funnel in Piwik so you get the correct data when you view the funnel reports. When you set up a funnel, it is crucial to have it configured correctly as the funnel report will be only as good as its configuration. When we built this Funnel feature, we focused on making the configuration and validation real simple because it is so important to get it right.

  To recap quickly : A Funnel defines a series of steps that you expect your visitors to take on their way to converting a goal or a sale. Funnels, a premium feature for Piwik developed by InnoCraft, lets you define funnels so you can improve your websites and mobile apps based on this data. Learn more about Funnel.

  Configuring a funnel

  As you will notice Funnels integrates nicely into the Piwik Goals management. You can configure a funnel whenever you create or update a goal. You can access the Goals Management either via “Administration => Goals” or via the reporting menu “Goals => Manage”. Then click on either “Add a new goal” or select an existing goal to edit it. At the bottom of the goal form, you will see a new row letting you configure a funnel. As with all our premium features we focused on displaying lots of inline help and explain directly in the UI what a funnel is about, what the steps are in order to configure a funnel, how a funnel helps you and more. This lets you use the Funnel feature even if you have never created or analyzed a funnel before.

  Preparing your Funnel configuration

  Before starting to configure a Funnel we usually have a brainstorm session identifying the funnels on a website or app and the paths we expect users to take there. Once we have identified each step, we click through those identified pages in our website and we note the URLs for each page as the URLs will be needed when you configure a funnel.

  Setting up a Goal

  Once we have finished the planning phase it is time to log into Piwik. We start by either adding a new goal or selecting an existing goal. If you are unfamiliar with setting up goals, have a look at the Piwik Goals user guide. At the bottom of a goal form when you create or update a goal, you can configure your funnel. The UI will first explain you everything about Funnels, what they are, how they help you and which steps you need to take in order to configure it.

  Configuring Funnel steps

  We start by configuring the steps we have identified in the planning phase. Those are the steps we expect our users to take when they convert a goal or purchase something. Now we need to add a step for each page we expect users to take, each step consists of a name and a pattern.

  The name will be shown to you in the funnel reporting so think of a good name that describes each step best, for example “Product”, “Cart”, “Checkout” and “Order”.

  The pattern is needed to define when a visitor will enter this step. Here it comes in handy to have already notes for each URL from the planning phase. You can select lots of different patterns based on “URL Path”, “URL” and “URL parameter”. For example “URL starts with”, “Path ends with”, “URL contains”, “URL matches the regular expression”, and more. Most tools make this configuration unnecessarily hard because they only allow you to choose from one or two patterns (only complicated pattern like regular expressions) and they don’t let you validate whether the URL you have in mind actually matches the pattern. There are three ways to validate your step configurations.

  

  Validating funnel steps

  When we configure a funnel, we validate our steps in the following three ways.

  1. Via the help icon next to the step configuration

  When you click on the help icon, you will receive valuable tips about configuring steps, what “required” means and how to match popular pages. It will also show you a list of all URLs that were tracked in your Piwik in the past and match your specified pattern. For example say you specify a pattern “Path starts with /products”, then Piwik will list all URLs that were tracked in the past matching this pattern. This lets you validate whether your pattern actually matches the URLs you had in mind. It will also show you if the pattern doesn’t match any known URL which can indicate that your configuration may be wrong.

  

  2. Via the URL validator

  Below the steps configuration you find a form field that lets you enter any URL.

  

  We recommend to enter each URL that you have noted before in the planning phase. Once you enter a URL, the configurations will be validated immediately and the result will be shown to you in the step configuration. When a step matches your specified URL, the background will become green, when a step does not match the URL, the background will be red.

  

  If the URL does not match the expected step, simply change your step configuration and the steps will be re-validated as you change the configuration. This way you will see instantly as soon as you got the configuration right.

  What you don’t want is that either all of your steps don’t match (red background) or that several steps match a certain URL (green background). When several step match one URL, then one visitor might enter several funnel steps on just one page. This usually indicates a problem with the step configuration.

  3. Manual funnel validation

  After we have created or updated the goal (more about this soon), we always test a funnel configuration manually. This means we now open our website and click through the pages that we hand in mind and check afterwards whether the steps we took actually appear in the funnel report as expected. This is just another safety net to make sure your funnel configuration is right.

  It is really crucial to have a correct funnel configuration as otherwise the shown data in the funnel reports might not be as helpful. That’s why we focused so much on making the validation part real easy.

  Activating and saving the funnel

  Once you are happy with your configuration, it is time to activate your funnel. As soon as you activate your funnel, a report for this funnel will be generated and the links and reports for this funnel will be visible in the UI. If you are later no longer interested in the funnel, simply deactivate the funnel so it won’t appear in the reporting UI anymore.

  

  To save your funnel configuration simply click on either “Add goal” or “Update goal”. The funnel will be automatically saved whenever you update your goal.

  Goals Management

  The funnel plugin also enriches the list of goals in the Piwik goal management. At a glance you can see whether a funnel for a goal is configured and activated (green tick in the funnel column), whether a funnel is configured but not activated (grey tick in the funnel column) or whether no funnel is configured for a goal (no tick at all).

  

  How to get Funnels and related features

  You can get Funnels on the Piwik Marketplace. If you want to learn more about Funnels you might be also interested in the Funnel User Guide and the Funnel FAQ.

  Similar to Funnels we also offer Users Flow which lets you visualize the flow of your users and visitors across several interactions.

• ffmpeg : Audio out of sync after conversion mp4 -> DNxHD

  7 février 2019, par Daniel E

  Based on this post I used the command :

  ffmpeg -i input.mp4 -c:v dnxhd -vf "scale=1280:720,fps=29.90,format=yuv422p" -b:v 110M -c:a pcm_s16le output.mov

  to convert an mp4 file to mov with the dnxhd video codec. I also want the pcm_s16le audio codec.

  Here you can see the input file’s properties :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'mexico-raw-combined.mp4':                                                                                                                                             
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512 
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.23.101
  
    Duration: 00:49:59.01, start: 0.000000, bitrate: 17220 kb/s
  
      Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 16961 kb/s, SAR 1:1 DAR 16:9, 29.90 fps, 29.92 tbr, 90k tbn, 180k tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandle
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 249 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandle

  And here are the output file’s properties :

   Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mov':
  
    Metadata:
  
      major_brand     : qt  
  
      minor_version   : 512
  
      compatible_brands: qt  
  
      encoder         : Lavf58.12.100
  
    Duration: 00:49:59.01, start: 0.000000, bitrate: 111235 kb/s
  
      Stream #0:0(eng): Video: dnxhd (DNXHD) (AVdn / 0x6E645641), yuv422p(tv, bt709/unknown/unknown), 1280x720, 109733 kb/s, SAR 1:1 DAR 16:9, 29.90 fps, 29.90 tbr, 19136 tbn, 19136 tbc (default)
  
      Metadata:
  
        handler_name    : DataHandler
  
        encoder         : Lavc58.18.100 dnxhd
  
      Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
  
      Metadata:
  
        handler_name    : DataHandler

  The issue is that towards the end of the output file (keep in mind it’s a 50 min video) the audio ends a bit ahead of the video, and the last 1 min 10 seconds are silent for some reason.

  Also note that I chose a framerate of 29.9 fps because that’s what the input file uses.