Recherche avancée

Sur d’autres sites (9411)

• Wipe image in and out with ffmpeg / imagemagick

  29 septembre 2017, par alexschomb

  I’d like to create a wipe in/out from left to right effect with ffmpeg and/or ImageMagick that is common to most video editors. (e.g. Adobe Premiere, Final Cut Pro and even OpenShot) Some might call this a slide in/out transition effect.

  I found that ffmpeg has a lot of filters (including fades), but none seem to be the correct choice for this.

  There are also ImageMagick transitions that achieve a wipe in effect. Like in the following example (that is derived from here) :

  convert overlay.png -crop 10x1080 miff:- | convert - out.gif

  But I found it hard to control the actual speed/duration of the transition. I’d like it to last only 2.5 seconds. But I can’t make it that fast, because the -delay 1x30 option doesn’t seem to let me decrease the delay that low. There is also a library with ImageMagick transitions here that unfortuantely isn’t compatible with batch.

  I suppose there is a solution for ffmpeg that I couldn’t think of, yet. I’d really appreciate your advice !

• Assigning of dts values to encoded packets

  24 mars, par Alex

  I have a dump of H264-encoded data, which I need to put in mp4 container. I verified the validity of the encoded data by using mp4box utility against it. The mp4 file created by mp4box contained a proper 17 seconds long video. It is interesting that if I try ffmpeg to achieve the same, the resulting video is 34 seconds long and rather crappy (probably ffmpeg tries to decode video and then encode it, which results in the loss of video quality ?) Anyway, for my project I can't use command line approach and need to come up wit a programmatic way to embed the data in the mp4 container.

  



  Below is the code I use (I removed error checking for brevity. During execution all the calls succeed) :

  



  AVFormatContext* pInputFormatContext = avformat_alloc_context();
avformat_open_input(&pInputFormatContext, "Data.264", NULL, NULL);
avformat_find_stream_info(pInputFormatContext, NULL);
AVRational* pTime_base = &pInputFormatContext->streams[0]->time_base;

int nFrameRate = pInputFormatContext->streams[0]->r_frame_rate.num / pFormatCtx->streams[0]->r_frame_rate.den;
int nWidth = pInputFormatContext->streams[0]->codecpar->width;
int nHeight = pInputFormatContext->streams[0]->codecpar->height;
// nWidth = 1920, nHeight = 1080, nFrameRate = 25

// Create output objects
AVFormatContext* pOutputFormatContext = NULL;
avformat_alloc_output_context2(&pOutputFormatContext, NULL, NULL, "Destination.mp4");

AVCodec* pVideoCodec = avcodec_find_encoder(pOutputFormatContext->oformat->video_codec/*AV_CODEC_ID_264*/);
AVStream* pOutputStream = avformat_new_stream(pOutputFormatContext, NULL);
pOutputStream->id = pOutputFormatContext->nb_streams - 1;
AVCodecContext* pCodecContext = avcodec_alloc_context3(pVideoCodec);

switch (pVideoCodec->type) {
case AVMEDIA_TYPE_VIDEO:
  pCodecContext->codec_id = codec_id;
  pCodecContext->bit_rate = 400000;
  /* Resolution must be a multiple of two. */
  pCodecContext->width = nFrameWidth;
  pCodecContext->height = nFrameHeight;
  /* timebase: This is the fundamental unit of time (in seconds) in terms
  * of which frame timestamps are represented. For fixed-fps content,
  * timebase should be 1/framerate and timestamp increments should be
  * identical to 1. */
  pOutputStream->time_base.num = 1;
  pOutputStream->time_base.den = nFrameRate;
  pCodecContext->time_base = pOutputStream->time_base;
  pCodecContext->gop_size = 12; /* emit one intra frame every twelve frames at most */
  pCodecContext->pix_fmt = STREAM_PIX_FMT;
  break;
default:
  break;
}

/* copy the stream parameters to the muxer */
avcodec_parameters_from_context(pOutputStream->codecpar, pCodecContext);

avio_open(&pOutputFormatContext->pb, "Destination.mp4", AVIO_FLAG_WRITE);

// Start writing
AVDictionary* pDict = NULL;
avformat_write_header(pOutputFormatContext, &pDict);

// Process packets
AVPacket packet;
int64_t nCurrentDts = 0;
int64_t nDuration = 0;
int nReadResult = 0;

while (nReadResult == 0)
{
  nReadResult = av_read_frame(m_pInputFormatContext, &packet);
// At this point, packet.dts == AV_NOPTS_VALUE. 
// The duration field of the packet contains valid data

  packet.flags |= AV_PKT_FLAG_KEY;
  nDuration = packet.duration;
  packet.dts = nCurrentDts;
  packet.dts = av_rescale_q(nCurrentDts, pOutputFormatContext->streams[0]->codec->time_base, pOutputFormatContext->streams[0]->time_base);
  av_interleaved_write_frame(pOutputFormatContext, &packet);
  nCurrentDts += nDuration;
  nDuration += packet.duration;
  av_free_packet(&packet);
}

av_write_trailer(pOutputFormatContext);


  



  The properties for the Destination.mp4 file I receive indicate it is about 1 hour long with frame rate 0. I am sure the culprit is in the way I calculate dts values for each packet and use av_rescale_q(), but I do not have sufficient understanding of the avformat library to figure out the proper way to do it. Any help will be appreciated !

  


• How you can use the Piwik AOM plugin to improve your data and make better online marketing decisions

  13 septembre 2017, par André Kolell — Plugins, AdWords, Bing, Case Study, Criteo, eccommerce tracking, Facebook Ads, how to install piwik analytics, how-to piwik, integration, piwik, Taboola

  Hi, this is André, one of the authors of the Piwik Advanced Online Marketing plugin, which has just hit 5,000 downloads on the Piwik marketplace. In this blog post I’ll show you how Piwik AOM improves your data and enables you to make better online marketing decisions.

  Piwik itself is excellent in tracking all kinds of visitor data, like where a visitor is coming from and what he’s doing on your page or app (pageviews, events, conversions). But what Piwik did not yet take a closer a look at, is how much you’ve invested into your marketing activities and how profitable they are.

  With the Piwik AOM plugin you can integrate data like advertising costs, advertising campaign names, ad impressions etc. from advertising platforms (such as Google AdWords, Microsoft Bing, Criteo, Facebook Ads and Taboola) and individual campaigns (such as such as cost per view/click/acquisition and fixed price per months deals) into Piwik and combine that data with individual Piwik visits.

  Piwik AOM adds a new marketing performance report to Piwik giving you a great overview of all your marketing activities with drill-down functionality :

  

   

  When taking a look at a specific visitor, Piwik AOM shows you the exact cost of acquiring a specific visit :

  

   

  Leveraging Piwik AOM’s full potential

  But although you can access Piwik AOM’s valuable data directly in the Piwik UI for ad-hoc analyses, Piwik AOM’s true strength comes into play when working with the raw data in an external business intelligence application of your choice, where you can further integrate Piwik AOM’s data with your most accurate backend data (like conversion’s contribution margins after returns, new vs. existing customer, etc.).

  Piwik AOM offers some API endpoints that allow you to fetch the data you need but you can also retrieve it directly from Piwik AOM’s aom_visits table, which includes all visits, all allocated advertising costs and advertising campaign details. As there is never data being deleted from aom_visits, the table can easily be connected to your ETL tool with its last update timestamp column. A third way to get data out of Piwik AOM is by developing your own Piwik plugin and listening to the AOM.aomVisitAddedOrUpdated event, which is posted whenever an aom_visits record is added or updated.

  Integrating Piwik AOM’s data with your backend data in the business intelligence application of your choice allows you to evaluate the real performance of your online marketing campaigns when applying different conversion attribution models, conduct customer journey analyses, create sophisticated forecasts and whatever you can think of.

  AOM Use case

  A company that followed this approach, is FINANZCHECK.de, one of Germany’s leading loan comparison websites. At the eMetrics summit 2016 in Berlin, Germany, I gave a talk about FINANZCHECK’s architectural online marketing setup. Until recently, FINANZCHECK used Pentaho data integration to integrate data from Piwik, Piwik AOM and additional internal tools like its proprietary CRM software into Jaspersoft, its data warehouse an BI solution. The enriched data in Jaspersoft was not only used for reporting to various stakeholders but also for optimising all kinds of marketing activities (e.g. bids for individual keywords in Google AdWords) and proactive alerting. Not long ago, FINANZCHECK started an initiative to improve its setup even further – I’ll hopefully be able to cover this in a more detailed case study soon.

  Roadmap

  In the past, we had the chance to make great progress in developing this plugin by solving specific requirements of different companies who use Piwik AOM. During the next months, we plan to integrate more advertising platforms, reimplement Facebook Ads, improve the support of individual campaigns and work on the general plugin stability and performance.

  Before you install Piwik AOM

  Before installing Piwik AOM, you should know that its initial setup and even its maintenance can be quite complex. Piwik AOM will heavily modify your Piwik installation and you will only benefit from Piwik AOM if you are willing to invest quite some time into it.

  If you are not familiar with Piwik’s internals, PHP, MySQL, database backups, cronjobs, creating API accounts at the advertising platforms or adding parameters to your advertising campaign’s URLs, you should probably not install it on your own (at least not in your production environment).

  Piwik AOM has successfully been tested with up to 25k visitors a day for a period of more than two years, running on an AWS server with 4 GB RAM, once CPU and a separate AWS RDS MySQL database.

  Ideas and Support

  If you have ideas for new features or need support with your Piwik AOM installation or leveraging your marketing data’s potential in general, feel free to get in touch with the plugin’s co-author Daniel or me. You can find our contact details on the plugin’s website http://www.advanced-online-marketing.com.

  How to get the Piwik AOM plugin ?

  The Piwik AOM plugin is freely available through the Piwik marketplace at https://plugins.piwik.org/AOM

  Did you like this article ? If yes do not hesitate to share it or give your feedback about the topic you would like us to write about.