Recherche avancée

Sur d’autres sites (6513)

• Dreamcast Finds

  15 avril 2022, par Multimedia Mike — Sega Dreamcast

  Pursuant to my recent post about finally understanding how Sega Dreamcast GD-ROM rips are structured, I was able to prepare the contents of various demo discs in a manner that makes exploration easy via the Internet Archive. This is due to the way that IA makes it easy to browse archives such as ZIP or ISO files (anything that 7zip knows how to unpack), and also presents the audio tracks for native playback directly through the web browser.

  These are some of the interesting things I have found while perusing the various Dreamcast sampler discs.

  Multimedia Formats
  First and foremost : Multimedia-wise, SFD and ADX files abound on all the discs. SFD files are Sofdec, a middleware format used for a lot of FMV on Dreamcast games. These were little more than MPEG video files with a non-MPEG (ADPCM instead) audio codec. VLC will usually play the video portions of these files but has trouble detecting the audio. It’s not for lack of audio codec support because it can play the ADX files just fine.
  

  It should be noted that Dreamcast Magazine Disc 11 has an actual .mpg file (as opposed to a .sfd file) that has proper MPEG audio instead instead of ADX ADPCM.

  The only other multimedia format I know of that was used in any Dreamcast games was 4XM, used on Alone In The Dark : The New Nightmare. I wrote a simple C tool a long time to recover these files from a disc image I extracted myself. Rather than interpreting the ISO-9660 filesystem, the tool just crawled through the binary blob searching for ‘4XMV’ file signatures and using length data within the files for extraction.

  Also, there are plentiful PVR files (in reference to the PowerVR2 GPU hardware that the DC uses) which ‘file’ dutifully identifies as “Sega PVR image”. There are probably tools to view them. It doesn’t appear to be a complicated format.

  Scripting
  I was fascinated to see Lua files on at least one of the discs. It turns out that MDK 2 leverages the language, as several other games do. But it was still interesting to see the .lua files show up in the Dreamcast version as well.

  That Windows CE Logo
  Every Sega Dreamcast is famously emblazoned with a logo mentioning Microsoft Windows CE :

  
  
  

  It has confused many folks. It also confused me until this exploratory exercise. Many would wonder if the Dreamcast booted up into some Windows CE OS environment that then ran the game, but that certainly wasn’t it. Indeed, Dreamcast was one of the last consoles that really didn’t have any kind of hypervisor operating system managing everything.

  I found a file called rt2dc.exe on one sampler disc. At first, I suspected that this was a development utility for Windows to convert some “RT” graphical format into a format more suitable for the Dreamcast. Then, ‘file’ told me that it was actually a Windows EXE but compiled for the Hitachi SH-4 CPU (the brain inside the DC). Does the conversion utility run on the Dreamcast itself ? Then I analyzed the strings inside the binary and saw references to train stations. That’s when it started to click for me that this was the binary executable for the demo version of Railroad Tycoon 2 : Gold Edition, hence “rt2dc.exe”. Still, this provides some insight about whether Dreamcast “runs” Windows. This binary was built against a series of Windows CE libraries. The symbols also imply DirectX compatibility.

  Here is a page with more info about the WinCE/DirectX variant for the Sega Dreamcast. It seems that this was useful for closing the gap between PC and DC ports of games (i.e., being able to re-use more code between the 2 platforms). I guess this was part of what made Dreamcast a dry run for the DirectXbox (later Xbox).

  Here is a list of all the Dreamcast games that are known to use Windows CE.

  Suddenly, I am curious if tools such as IDA Pro or Ghidra can possibly open up Windows CE binaries that contain SH-4 code. Not that I’m particularly interested in reverse engineering any algorithms locked up in Dreamcast land.

  Tomb Raider Easter Egg
  The volume 6 sampler disc has a demo of Tomb Raider : The Last Revelation. While inspecting the strings, I found an Easter egg. I was far from the first person to discover it, though, as seen on this The Cutting Room Floor wiki page (look under “Developer Message”). It looks like I am the first person to notice it on the Dreamcast version. It shows up at offset 0xE3978 in the Dreamcast (demo version) binary, if anyone with permissions wants to update the page.

  Web Browser
  Then there’s the Web Browser for Sega Dreamcast. It seemed to be included on a lot of these sampler discs. But only mentioning the web browser undersells it– the thing also bundled an email client and an IRC client. It’s important to remember that the Dreamcast also had a keyboard peripheral.

  I need to check the timeline for when the web browser first became available vs. when the MIL-CD hack became known. My thinking is that there is no way that the web browser program didn’t have some security issues– buffer overflows and the like. It seems like this would have been a good method of breaking the security of the system.

  Ironically, I suddenly can think of a reason why one might want to use advanced reverse engineering tools on Dreamcast binaries, something I struggled with just a few paragraphs ago.

  Odds ‘n Ends
  It’s always fun to find plain text files among video game assets and speculating on the precise meaning… while also marveling how long people have been struggling to correctly spell “length”.

  Internationalization via plain text files.

  Another game (Slave Zero) saw fit to zip its assets. Maybe this was to save space in order to fit everything on the magazine sampler disc. Quizzically, this didn’t really save an appreciable amount of space.

  Finally, all the discs have an audio track 2 that advises that the disc must be played in a Dreamcast console. Not unusual. However, volume 4 also has a Japanese lady saying the same thing on track 4. This is odd because track 4 is one of the GD area audio tracks and is not accessible with normal CD hardware. Further, she identifies the disc as a “Windows CE disc”.

  The post Dreamcast Finds first appeared on Breaking Eggs And Making Omelettes.

• FFMPEG — using 'amix' to combine short audio clip with a video results in final video's sound cutting off early

  12 avril 2022, par kilika

  I am trying to combine the following :

  


  (a) : 29s video clip that has its own audio that lasts the entire duration

  


  (b) : audio clip I want to play at the start of the video, in conjunction with original audio, and is 2 seconds long

  


  I successfully use 'amix' to obtain a video at the end with combined audio, but the problem is that the final video's audio cuts off at around 26 out of the 29 seconds of the video and goes silent.

  


  What doesn't make any sense is that the resulting video plays as it should, with the audio successfully mixed. But the output video's audio stream loses the last 3 seconds.

  


  Here's the 'amix' command I'm using (sending via subprocess) :

  


  subprocess.call(['ffmpeg','-i', input.mp4', '-i', "audioclip.mp3", '-filter_complex', 'amix', output.mp4'])


  


  I've also used versions of this command that spell out the -map "0:a" and -map "1:a", or tried using 'amix=inputs=2:duration:longest' among many other additions. All lead to the same problem : the final combined video's audio drops out with 3 seconds remaining in the video, even though the initial 'input.mp4' video has a full 29 out of 29 seconds of audio.

  


  Does anyone know why these last several seconds of audio from [a] are missing in the final video ?

  


  _________________________________________________________________

  


  edit : Below is my output when I run the amix command listed above :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advanced.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5441 kb/s
  Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 5304 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : Bento4 Sound Handler
      vendor_id       : [0][0][0][0]
[mp3 @ 000001f0c8ec2040] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from 'TTS_clip.mp3':
  Duration: 00:00:01.90, start: 0.000000, bitrate: 32 kb/s
  Stream #1:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
Stream mapping:
  Stream #0:1 (aac) -> amix (graph 0)
  Stream #1:0 (mp3float) -> amix (graph 0)
  amix:default (graph 0) -> Stream #0:0 (aac)
  Stream #0:0 -> #0:1 (h264 (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 000001f0c8cbe5c0] using SAR=1/1
[libx264 @ 000001f0c8cbe5c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000001f0c8cbe5c0] profile High, level 4.0, 4:2:0, 8-bit
[libx264 @ 000001f0c8cbe5c0] 264 - core 164 r3094 bfc87b7 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=24 lookahead_threads=4 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'RuneBearinstakill_advancedwithtts.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc59.25.100 aac
  Stream #0:1(eng): Video: h264 (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 30 fps, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.25.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=  893 fps=110 q=-1.0 Lsize=   18717kB time=00:00:29.66 bitrate=5168.5kbits/s speed=3.66x    
video:18256kB audio:433kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.150179%
[aac @ 000001f0c8f9ebc0] Qavg: 921.259
[libx264 @ 000001f0c8cbe5c0] frame I:4     Avg QP:21.33  size: 71366
[libx264 @ 000001f0c8cbe5c0] frame P:633   Avg QP:23.32  size: 23837
[libx264 @ 000001f0c8cbe5c0] frame B:256   Avg QP:25.22  size: 12968
[libx264 @ 000001f0c8cbe5c0] consecutive B-frames: 57.2% 10.3% 10.1% 22.4%
[libx264 @ 000001f0c8cbe5c0] mb I  I16..4: 17.9% 71.4% 10.8%
[libx264 @ 000001f0c8cbe5c0] mb P  I16..4:  6.9% 17.6%  0.8%  P16..4: 43.1%  6.5%  1.5%  0.0%  0.0%    skip:23.6%
[libx264 @ 000001f0c8cbe5c0] mb B  I16..4:  1.5%  4.2%  0.3%  B16..8: 39.7%  4.6%  0.5%  direct: 1.6%  skip:47.6%  L0:55.9% L1:41.8% BI: 2.3%
[libx264 @ 000001f0c8cbe5c0] 8x8 transform intra:69.5% inter:87.3%
[libx264 @ 000001f0c8cbe5c0] coded y,uvDC,uvAC intra: 35.6% 26.8% 0.8% inter: 13.4% 10.8% 0.0%
[libx264 @ 000001f0c8cbe5c0] i16 v,h,dc,p: 21% 37% 12% 30%
[libx264 @ 000001f0c8cbe5c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 26% 21%  4%  5%  5%  6%  4%  5%
[libx264 @ 000001f0c8cbe5c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 28% 15%  5%  7%  7%  7%  5%  4%
[libx264 @ 000001f0c8cbe5c0] i8c dc,h,v,p: 67% 18% 14%  1%
[libx264 @ 000001f0c8cbe5c0] Weighted P-Frames: Y:0.2% UV:0.0%
[libx264 @ 000001f0c8cbe5c0] ref P L0: 72.3% 15.4%  8.7%  3.6%  0.0%
[libx264 @ 000001f0c8cbe5c0] ref B L0: 88.9%  9.5%  1.6%
[libx264 @ 000001f0c8cbe5c0] ref B L1: 97.7%  2.3%
[libx264 @ 000001f0c8cbe5c0] kb/s:5024.13


  


  And here is the output when I check the stream durations for the input video and the output video, showing how the output video's audio stream is somehow reduced by several seconds after the amix :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advanced.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5403 kb/s
  Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 5266 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : Bento4 Sound Handler
      vendor_id       : [0][0][0][0]
[STREAM]
duration=29.766667
[/STREAM]
[STREAM]
duration=29.738000
[/STREAM]

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RuneBearinstakill_advancedwithtts.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf59.20.101
  Duration: 00:00:29.77, start: 0.000000, bitrate: 5098 kb/s
  Stream #0:0[0x1](und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt470bg/bt470bg/smpte170m, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 4971 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : Bento4 Video Handler
      vendor_id       : [0][0][0][0]
[STREAM]
duration=27.477000
[/STREAM]
[STREAM]
duration=29.766667


  


• Google Analytics 4 (GA4) vs Matomo

  7 avril 2022, par Erin

  Google announced that Universal Analytics’ days are numbered. Universal Analytics will be replaced by Google Analytics 4 (or GA4) on the 1st of July 2023. 

  If Google Analytics users want to compare year-on-year data, they have until July 2022 to get set up and start collecting data before the sun sets on Universal Analytics (or UA).

  But is upgrading to Google Analytics 4 the right move ? There’s a lot to consider, and many organisations are looking for an alternative to Google Analytics. So in this blog, we’ll compare GA4 to Matomo – the leading Google Analytics alternative. 

  In this blog, we’ll look at :

  What is Matomo ?

  Matomo is a powerful privacy-first web analytics platform that gives you 100% data ownership. First launched in 2007, Matomo is now the world’s leading open-source web analytics platform and is used by more than 1 million websites. 

  Matomo’s core values are based on ethical data collection and processing. Consistently more businesses and organisations from around the globe are adopting data-privacy-compliant web analytics solutions like Matomo. 

  Matomo offers both Cloud and On-Premise solutions (and a five-star rated WordPress plugin), making for an adaptable and flexible solution. 

  What is Google Analytics 4 ?

  Google Analytics 4 is the latest version of Google Analytics and represents a completely new approach to data-modelling than its predecessor, Universal Analytics. For an in-depth look at how GA4 and UA compare, check out this Google Analytics 4 vs Universal Analytics comparison. 

  Google Analytics 4 will soon be the only available version of analytics software from Google. So what’s the issue ? Surely, in 2022, Google makes it easy to migrate to their newest (and only) analytics platform ? Not quite.

  Google Analytics 4 vs Matomo

  Whilst the core purpose of GA4 and Matomo is similar (providing web analytics that help to optimise your website and grow your business), there are several key differences that organisations should consider before making the switch.

  Importing Historical Data from Universal Analytics

  Google Analytics 4

  Users assuming that historical data from Universal Analytics could be imported into Google Analytics 4 were faced with swift disappointment. Unfortunately, Google Analytics 4 does not have an option to import data from its predecessor, Universal Analytics. This means that businesses won’t be able to import and compare data from previous years.

  Matomo

  If you don’t want to start from scratch with your web analytics data, then Matomo is an ideal solution for data continuity. Matomo offers users the ability to import their historical Universal Analytics data. So you can keep all that valuable historical data you’ve collected over the years.

  

  User Interface

  Google Analytics 4

  GA4’s new user interface has been met with mixed reviews. Many claim that it’s overly complex and difficult to navigate. Some have even suggested that the tool has been designed specifically for enterprises with specialised analytics teams. 

  

  Matomo

  Matomo, on the other hand, is recognised for an easy to use interface, with a rating of 4.5 out of 5 stars for ease of use on Capterra. Matomo perfectly balances powerful features with a user-friendly interface so valuable insights are only a click away. There’s a reason why over 1 million websites are using Matomo. 

  

  Advanced Behavioural Analytics Features 

  Google Analytics 4

  While Google Analytics is undoubtedly robust in some areas (machine learning, for instance), what it really lacks is advanced behavioural analytics. Heatmaps, session recordings and other advanced tools can give you valuable insights into how users are engaging with your site. Well beyond pageviews and other metrics.

  Unfortunately, with this new generation of GA, Google still hasn’t introduced these features. So users have to manage subscriptions and tracking in third-party behavioural analytics tools like Hotjar or Lucky Orange, for example. This is inefficient, costly and time-consuming to manage. 

  

  Matomo 

  Meanwhile, Matomo is a one-stop shop for all of your web analytics needs. Not only do you get access to the metrics you’ve grown accustomed to with Universal Analytics, but you also get built-in behavioural analytics features like Heatmaps, Scroll Depth, Session Recordings and more. 

  Want to know if visitors are reaching your call to action at the bottom of the page ? Scroll Depth will answer that.

  Want to know why visitors aren’t clicking through to the next page ? Heatmaps will give you the insights you need.

  You get the picture – the full picture, that is. 

  

  Data Accuracy

  Google Analytics 4

  GA4 aims to make web and app analytics more privacy-centric by reducing the reliance on cookies to record certain events across platforms and devices. 

  However, when site and application visitors opt-out of cookie tracking, GA4 instead relies on machine learning to fill in the gaps. Data sampling could mean that your business is making business decisions based on inaccurate reports. 

  Matomo

  Data is the backbone of web analytics, so why make critical business decisions on sampled data ? With Matomo, you’re guaranteed 100% unsampled accurate data. So you can rest assured that any decisions you make are based on actual facts. 

  Compliance with Privacy Laws (GDPR, CCPA, etc.) 

  Google Analytics 4

  Google is making changes in an attempt to become compliant with privacy laws. However, even with GA4, users are still transferring data to the US. For this reason, both Austrian and French governments have ruled Google Analytics illegal under GDPR.

  The only possible workaround is “Privacy Shield 2.0”, but GDPR experts are still sceptical of this one. 

  Matomo

  If compliance with global privacy laws is a concern (and it should be), then Matomo is the clear winner here. 

  As an EU hosted web analytics tool, your data is stored in Europe, and no data is transferred to the US. On the other hand, if you choose to self-host, the data is stored in your country of choice.

  In addition, with cookieless tracking enabled, you can say goodbye to those pesky cookie consent screens. 

  Also, remember that under GDPR, and many other data privacy laws like CCPA and LGPD, end users have a legal right to access, amend and/or erase the personal data collected about them. 

  With Matomo you get 100% ownership of your web analytics data. This means that we don’t on-sell to third parties ; can’t claim ownership of the data ; and you can export your data at any time.

  

  Wrap up

  At the end of the day, the worst thing an organisation can do is nothing. Waiting until July 2023 to migrate to GA4 or another web analytics platform would be very disruptive and costly. Organisations need to consider their options now and start migrating in the next few months. 

  With all that said, moving to Google Analytics 4 could prove to be a costly and time-consuming operation. The global trend towards increased data privacy is a threat to platforms like Google Analytics which uses data for advertising and transfers data across borders.

  With Matomo, you get an easy to use all-in-one web analytics platform and keep your historical Universal Analytics data. Plus, you can future-proof your business by being compliant with global privacy laws and get access to advanced behavioural analytics features. 

  There’s a lot to weigh up here but fortunately, getting started with Matomo is easy. Try it free for 21-days (no credit card required) and see for yourself why over 1 million websites choose Matomo. 

  While this is the end of the road for Universal Analytics, it’s also an opportune time for organisations to find a better fit web analytics tool. 

  21 day free trial. No credit card required.

  Your email address
  

  Your website address
  

  Your Analytics subdomain will be .matomo.cloud (change)

  Choose your analytics subdomain
  

  .matomo.cloud

  I hereby accept the terms and conditions and the data processing agreeement (DPA).

  
  Your information will be used to create an account on our cloud service. For more information please consult our privacy policy.
  
  

  » Start improving your websites now