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• How to convert a Video to a Slideshow with synced audio ? [closed]

  25 mai 2013, par Henry Mazza

  I want a simple way to convert a Ted Talk Presentation to a SlideShow + (synced)Audio format so I can listen to it in my car. I don't want to lose most of the visuals as it does in the audio format and also want to reduce the storage/cell data needs of the video format.

  So far I already extracted the key scenes with timing and the audio, now I must glue this together in a synced fashion.

  Possible ways I found but couldn't make work :

  • MP4Box to make a .m4b (audiobook/enhanced podcast) with mp4chap to set each image as a chapter image (but I could find proper documentation on how to do this)
  • FFMPEG to make a flat movie with the images (but I couldn't make each image stay for a random period of time)

  Ultimately I will automate this process in my VPS and make my private podcast server, so no fancy tools that don't work in Linux, please.

  EDIT : actually the Podcast is a lousy idea, the artwork must be in a square aspect ratio and has great compatibility problems with varius players. Still studing the Book format.

• The Guide to an Ethical Web : With Big Data Comes Big Responsibility

  13 mars, par Alex Carmona

  Roughly two-thirds of Earth’s 8 billion people use the internet for communication, education, entertainment, business and more. We are connected globally in ways previous generations could’ve never dreamed of. It’s been a wild ride, and we’re just starting.

  Many users have learned that experiences online can be a mix of good and bad. Sometimes, the bad can feel like it outweighs the good, particularly when large tech companies use our data shadily, cut corners on accessibility or act in any other way that devalues the human being behind the screen.

  As fellow internet citizens, what responsibility do we have to create a more ethical web for our customers ?

  In this article, we’ll look at ethical principles online and how to act (and not act) to build trust, reach customers regardless of ability, safeguard privacy and stay compliant while improving business outcomes.

  

  What is an “ethical web” ?

  When we talk about the ethical web, we’re talking about the use of the internet in an ethical way. Among other values, it involves transparency, consent and restraint. It applies the Golden Rule to the internet : Treat others (and their data and user experience) how you’d want yourself (and yours) to be treated. 

  With limited oversight, the internet has evolved in ways that often prioritise profit over user rights. While selling data or pushing cookies might seem logical in this context, they can undermine trust and reputation. And the tide is slowly but surely shifting as consumers and legislators push back.

  Consumers no longer want to buy from companies that will use their data in ways they don’t agree to. In 2022, 75% of UK and US consumers surveyed said they were uncomfortable purchasing from businesses with weak data ethics.

  Legislators worldwide have been taking part in this effort for nearly a decade, with laws like GDPR in the EU and LGPD in Brazil, as well as the various state laws in the US, like California’s CCPA and Virginia’s VCDPA. 

  Even tech giants are no longer above the law, like Meta, which was fined over a billion Euros for GDPR violations in 2023.

  

  These changes may make the internet feel less business-friendly at first glance, but ethical choices ultimately build a stronger digital ecosystem for both companies and consumers. 

  Likewise, all internet users alike can make this happen by shunning short-term profit and convenience for healthier, long-term choices and behaviour.

  As we dig into what it takes to build an ethical web, remember that no company or individual is free from mistakes in these areas nor is it an overnight fix. Progress is made one click at a time.

  Ethical SEO : Optimising your content and your ethics

  Content creation and search engine optimisation (SEO) require so much work that it’s hard to fault creators for not always abiding by search engine guidelines and seeking shortcuts – especially when there’s a sea of LinkedIn posts about how copying/pasting ChatGPT responses helped someone rank #1 for several keywords in one week.

  However, users turn to Google and other search engines for something of substance that will guide or entertain them.

  Content meets customer needs and is more likely to lead to sales when it’s well-written, original and optimised just enough to make it easier to find on the first page of results. This doesn’t happen when content teams dilute quality and waste a reader or viewer’s time on posts that will only yield a higher bounce rate.

  Some SEO pros do find success by building backlinks through private blog networks or crafting a million unedited posts with generative AI, but it’s short-lived. Google and other search engines always catch up, and their content plummets or gets penalised and delisted with every new update.

  Content teams can still rank at the top while sticking to ethical SEO principles. Here’s a sample list of dos and don’ts to get started :

  • Do put content quality above all else. Make content that serves the audience, not just a brand or partner ad network.
  • Do apply the E-E-A-T framework. Search engines value content written by authors who bring expertise, experience, authority and trust (E-E-A-T).
  • Don’t keyword stuff. This might have worked in the early days of SEO, but it hurts readability and now harms article performance.
  • Do use alt text as intended. While it can still help SEO, alt text should prioritise accessibility for users with screen readers.

  • Don’t steal content. Whether it’s violating copyright, copying/pasting other people’s content or simply paraphrasing without citation, companies should never steal content.
  • Don’t steal ideas. It’s okay to join in on a current conversation or trends in an industry, but content creators should be sure they have something valuable to add.
  • Do use AI tools as partners, not creators. AI can be an incredible aid in crafting content, but it should never be posted without a human’s touch.

  When we follow ethical SEO guidelines and get more clients with our content, how do we best handle their data ?

  Ethical data governance : Important principles and how to avoid data misuse

  Data governance comprises every aspect of how a company manages data, including storage, security, privacy, lifecycle management, setting policies and maintaining compliance with laws like GDPR and HIPAA.

  Applying data ethics to governance is doing it all in a transparent, restrained way that acknowledges an individual’s right to ownership over their data. 

  For organisations, this translates to getting consent to collect data and clearly spelling out how it will be stored and used — and sticking to it.

  If a user’s birth date is needed for legal reasons, it cannot be sold to a third party or later used for something else without explicit permission. Reusing data in ways that stray from its original purpose is a form of commingling, one of the data misuses that is easy for even well-intentioned teams to do accidentally.

  Ethical data governance also includes the vigilant safeguarding of users’ data and minimising potential privacy issues.

  Failing to implement and adhere to strong security measures leads to situations like the National Public Data (NPD) breach, where cyber criminals expose the addresses, phone numbers and social security numbers of hundreds of millions of people. This was due in large part to a weakness in storing login credentials and a lack of password policy enforcement.

  No one at NPD wanted this to happen, but security likely took a backseat to other business concerns, leading to the company’s filing for bankruptcy.

  More importantly, as a data broker that aggregates information from other sources, the people affected likely had no clue this organisation had been buying and selling their data. The companies originally entrusted with their information helped provide the leaked data, showing a lack of care for privacy.

  Situations like this reinforce the need for strict data protection laws and for companies to refine their data governance approach. 

  Businesses can improve their data governance posturing with managers and other higher-ups setting the right tone at the top. If leadership takes a firm and disciplined approach by setting and adhering to strong policies, the rest of the team will follow and minimise the chances of data misuse and security incidents.

  One way to start is by using tools that make the principles of data ethics easier to follow.

  Ethical web analytics : Drawing insights while respecting privacy

  Web analytics tools are designed to gather data about users and what they do while visiting a site.
  The most popular tool worldwide is Google Analytics (GA). Its brand name and feature set carry a lot of weight, but many former users have switched to alternatives due to dissatisfaction with the changes made in GA4 and reservations about the way Google handles data.

  

  Google is another tech giant that has been slapped with massive GDPR fines for issues over its data processing practices. It has run so afoul of compliance that it was banned in France and Austria for a while. Additionally, in the US Department of Justice’s ongoing antitrust lawsuit against Google, the company’s data tracking has been targeted for both how it affects users and potential rivals.

  Unlike GA, ethical web analytics tools allow websites to get the data they need while respecting user privacy.

  Matomo offers privacy protections like :

  • Providing data anonymisation and IP anonymisation
  • Allowing users the ability to not process personally identifiable information (PII)
  • Disabling the ability to track users across websites by default to make compliance easier
  • Giving users full control over their customer data without the risk of it getting into the hands of third parties
  • Much more

  We’re also fully transparent about how we handle your data on the web and in the Matomo Cloud and in how we build Matomo as an open-source tool. Our openness allows you to be more open with your customers and how you ethically use their data.

  There are other GDPR-compliant tools on the market, but some of them, like Adobe Analytics, require more setup from users for compliance, don’t grant full control over data and don’t offer on-premise options or consent-free tracking.

  Beyond tracking, there are other ways to make a user’s experience more enjoyable and ethical.

  Ethical user experience : User-friendliness, not user-hostility

  When designing a website or application, creating a positive user experience (UX) always comes first. 

  The UI should be simple to navigate, data and privacy policy information should be easy to find and customers should feel welcomed. They must never be tricked into consenting or installing. 

  When businesses resort to user-hostile tactics, the UX becomes a battle between the user and them. What may seem like a clever tactic to increase sign-ups can alienate potential customers and ruin a brand’s image. 

  Here are some best practices for creating a more ethical UX :

  Avoid dark patterns

  Dark patterns are UI designs and strategies that mislead users into paying for, agreeing to or doing something they don’t actually want. These designs are unethical because they’re manipulative and remove transparency and consent from the interaction. 

  In some cases, they’re illegal and can bring lawsuits. 

  In 2023, Italy’s Data Protection Authority (DPA) fined a digital marketing company €300,000 for alleged GDPR violations. They employed dark patterns by asking customers to accept cookies again after rejecting them and placing the option to reject cookies outside the cookie banner. 

  Despite their legality and 56% of surveyed customers losing trust in platforms that employ dark patterns, a review by the Organisation for Economic Co-operation and Development (OECD) found that 76% of the websites examined contained at least one dark pattern.

  

  If a company is worried that they may be relying on dark patterns, here are some examples of what to avoid :

  • Pre-ticking boxes to have users agree to third-party cookies, sign up for a newsletter, etc.
  • Complicated cookie banners without a one-click way to reject all unnecessary cookies
  • Hiding important text with text colour, under drop-down menus or requiring hovering over something with a mouse 
  • “Confirm shaming” users with emotionally manipulative language to delay subscription cancellations or opt out of tracking 

  Improve trust centres

  Trust centres are the sections of a website that outline how a company approaches topics like data governance, user privacy and security. 

  They should be easy to find and understand. If a user has a question about a company’s data policy, it should be one click away with language that doesn’t require a law degree to comprehend.

  Additionally, trust centres must cover all relevant details, including where data is stored and who does the subprocessing. This is an area where even some of the best-intentioned companies may miss the mark, but it’s also an easy fix and a great place to start creating a more ethical web.

  Embrace inclusivity

  People want to feel welcomed to the party — and deserve to be — regardless of their race, ethnicity, religion, gender identity, orientation or ability. 

  Inclusivity is great for customers and companies alike. 

  A study by the Unstereotype Alliance found that progressive marketing drove up short- and long-term sales, customer loyalty and purchase consideration. A Kantar study reported that 75% of surveyed customers around the world consider a company’s diversity and inclusivity when making a purchasing decision.

  An easy place to start embracing inclusivity is with a website’s blog images. The people in photos and cartoons should reflect a variety of different backgrounds.

  Another area to improve inclusivity is by making your site or app more accessible.

  Accessibility ethics : An internet for everyone

  Accessibility is designing your product in a way that everyone can enjoy or take part in, regardless of ability. Digital accessibility is applying this design to the web and applications by making accommodations like adding descriptive alt text to images for users with visual impairments.

  Just because someone has a hearing, vision, speech, mobility, neurological or other impairment doesn’t mean they have any less of a right to shop online, read silly listicles or get into arguments with strangers in the comment section.

  Beyond being the right thing to do, the Fable team shows there’s a strong business case for accessibility. People with disabilities have money to spend, and the accommodations businesses make for them often benefit people without disabilities, too – as anyone who streams with subtitles can attest.

  Despite being a win-win for greater inclusivity and business, much of the web is still inaccessible. WebAIM, a leader in web accessibility, studied a million web pages and found an average of over 55 accessibility errors per page.

  We must all play a more active role in improving the experience of our users with disabilities, and we can start with accessibility auditing and testing.

  An accessibility audit is an evaluation of how usable a site is for people with disabilities. It may be done in-house by an expert on a company’s team or, for better results, a third-party consultant who can give a fully objective audit.

  Auditing might consist of running an automated tool or manually checking your site, PDFs, emails and other materials for compliance with the Web Content Accessibility Guidelines list.

  Accessibility testing is narrower than auditing. It checks how accessibility or its absence looks in action. It can be done after a site, app, email or product is released, but it ideally starts in the development process.

  Testing should be done manually and with automated tools. Manual checks put developers in the position of their users, allowing them to get a better idea of what users are dealing with firsthand. Automated tools can save time and money, but there should always be manual testing in the process.

  Auditing gives teams an idea of where to start with improving accessibility, and testing helps make sure accommodations work as intended.

  Conclusion

  At Matomo, we strive to make the ethical web a reality, starting with web analytics.

  For our users, it means full compliance with stringent policies like GDPR and providing 100% accurate data. For their customers, it’s collecting only the data required to do the job and enabling cookieless configurations to get rid of annoying banners. 

  For both parties, it’s knowing that respect for privacy is one of our foundational values, whether it’s the ability to look under Matomo’s hood and read our open-source code, the option to store data on-premise to minimise the chances of it falling into the wrong hands or one of the other ways that we protect privacy.

  If you weren’t 100% ethical before, it’s never too late to change. You can even bring your Google Analytics data with you.

  Join us in our mission to improve the web. We can’t do it alone ! 

  Try Matomo free for 21 days

  no credit card required

• ffmpeg API h264 encoded video does not play on all platforms

  19 juillet 2012, par TheSHEEEP

  Edit : In the previous version I used a very old ffmpeg API. I now use the newest libraries. The problem has only changed slightly, from "Main" to "High".

  I am using the ffmpeg C API to create a mp4 video in C++.

  I want the resulting video to be of the profile "Constrained Baseline", so that the resulting video can be played on as much platforms as possible, especially mobile, but I get "High" profile every time, even though I hard coded the codec profile to be FF_PROFILE_H264_CONSTRAINED_BASELINE. As a result, the video does not play on all our testing platforms.

  This is what "ffprobe video.mp4 -show_streams" tells about my video streams :

    Metadata:
  
  major_brand     : isom
  
  minor_version   : 512
  
  compatible_brands: isomiso2avc1mp41
  
  creation_time   : 1970-01-01 00:00:00
  
  encoder         : Lavf53.5.0
  
    Duration: 00:00:13.20, start: 0.000000, bitrate: 553 kb/s
  
  Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 320x180,
  
  424 kb/s, 15 fps, 15 tbr, 15 tbn, 30 tbc
  
  Metadata:
  
    creation_time   : 1970-01-01 00:00:00
  
    handler_name    : VideoHandler
  
  Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 12
  
  kb/s
  
  Metadata:
  
    creation_time   : 1970-01-01 00:00:00
  
    handler_name    : SoundHandler
  
  -------VIDEO STREAM--------
  
  [STREAM] 
  
  index=0
  
  codec_name=h264
  
  codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
  
  
  
  profile=High <-- This should be "Constrained Baseline"
  
  
  
  codec_type=video
  
  codec_time_base=1/30
  
  codec_tag_string=avc1
  
  codec_tag=0x31637661
  
  width=320
  
  height=180
  
  has_b_frames=0
  
  sample_aspect_ratio=N/A
  
  display_aspect_ratio=N/A
  
  pix_fmt=yuv420p
  
  level=30
  
  timecode=N/A
  
  is_avc=1
  
  nal_length_size=4
  
  id=N/A
  
  r_frame_rate=15/1
  
  avg_frame_rate=15/1
  
  time_base=1/15
  
  start_time=0.000000
  
  duration=13.200000
  
  bit_rate=424252
  
  nb_frames=198
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  TAG:creation_time=1970-01-01 00:00:00
  
  TAG:language=und
  
  TAG:handler_name=VideoHandler
  
  [/STREAM]
  
  -------AUDIO STREAM--------
  
  [STREAM]
  
  index=1
  
  codec_name=aac
  
  codec_long_name=Advanced Audio Coding
  
  profile=unknown
  
  codec_type=audio
  
  codec_time_base=1/44100
  
  codec_tag_string=mp4a
  
  codec_tag=0x6134706d
  
  sample_fmt=s16
  
  sample_rate=44100
  
  channels=2
  
  bits_per_sample=0
  
  id=N/A
  
  r_frame_rate=0/0
  
  avg_frame_rate=0/0
  
  time_base=1/44100
  
  start_time=0.000000
  
  duration=13.165714
  
  bit_rate=125301
  
  nb_frames=567
  
  nb_read_frames=N/A
  
  nb_read_packets=N/A
  
  TAG:creation_time=1970-01-01 00:00:00
  
  TAG:language=und
  
  TAG:handler_name=SoundHandler
  
  [/STREAM]

  This is the function I use to add a video stream. All the values that come from ptr-> are defined from outside, do those values have to be specific values to get the correct profile ? :

  static AVStream *add_video_stream( Cffmpeg_dll * ptr, AVFormatContext *oc, enum   CodecID codec_id )
  
  {
  
  AVCodecContext *c;
  
  AVStream *st;  
  
  AVCodec* codec;
  
  
  
  // Get correct codec
  
  codec = avcodec_find_encoder(codec_id);
  
  if (!codec) {
  
      av_log(NULL, AV_LOG_ERROR, "%s","Video codec not found\n");
  
      exit(1);
  
  }
  
  
  
  // Create stream
  
  st = avformat_new_stream(oc, codec);
  
  if (!st) {
  
      av_log(NULL, AV_LOG_ERROR, "%s","Could not alloc stream\n");
  
      exit(1);
  
  }
  
  
  
  c = st->codec;
  
  
  
  /* Get default values */
  
  codec = avcodec_find_encoder(codec_id);
  
  if (!codec) {
  
      av_log(NULL, AV_LOG_ERROR, "%s","Video codec not found (default values)\n");
  
      exit(1);
  
  }
  
  avcodec_get_context_defaults3(c, codec);
  
  
  
  c->codec_id = codec_id;
  
  c->codec_type = AVMEDIA_TYPE_VIDEO;
  
  
  
  c->bit_rate = ptr->video_bit_rate;
  
  av_log(NULL, AV_LOG_ERROR, " Bit rate: %i", c->bit_rate);
  
  
  
      c->qmin = ptr->qmin;
  
      c->qmax = ptr->qmax;
  
      c->me_method = ptr->me_method;
  
      c->me_subpel_quality = ptr->me_subpel_quality;
  
      c->i_quant_factor = ptr->i_quant_factor;
  
      c->qcompress = ptr->qcompress;
  
      c->max_qdiff = ptr->max_qdiff;
  
  
  
      // We need to set the level and profile to get videos that play (hopefully) on all platforms
  
      c->level = 30;
  
      c->profile = FF_PROFILE_H264_CONSTRAINED_BASELINE;
  
  
  
  c->width = ptr->dstWidth; 
  
  c->height = ptr->dstHeight; 
  
  
  
  c->time_base.den = ptr->fps;
  
  c->time_base.num = 1;
  
  c->gop_size = ptr->fps;
  
  c->pix_fmt = STREAM_PIX_FMT;
  
  c->max_b_frames = 0;
  
  
  
  // some formats want stream headers to be separate
  
  if(oc->oformat->flags & AVFMT_GLOBALHEADER)
  
      c->flags |= CODEC_FLAG_GLOBAL_HEADER;
  
  
  
  return st;
  
  }

  Additional info :

  As a reference video, I use the gizmo.mp4 that Mozilla serves as an example that plays on every platform/browser. It definitely has the "Constrained Baseline" profile, and definitely works on all our testing smartphones. You can download it here. Our self-created video doesn't work on all platforms and I'm convinced this is because of the profile.

  I am also using qt-faststart.exe to move the headers to the start of the file after creating the mp4, as this cannot be done in a good way in C++ directly. Could that be the problem ?

  Obviously, I am doing something wrong, but I don't know what it could be. I'd be thankful for every hint ;)