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• Video Processing Library on Windows Phone 8

  3 avril 2015, par ssk

  Are there video processing library on Windows phone 8 ? I am trying to convert very short videos from one format to another. From what I searched, FFMPEG is not available for windows phone : Using FFmpeg in .net ?

  Is there an SDK support for video processing on Windows Phone ?

• Game Music Appreciation, One Year Later

  1er août 2013, par Multimedia Mike — General

  I released my game music website last year about this time. It was a good start and had potential to grow in a lot of directions. But I’m a bit disappointed that I haven’t evolved it as quickly as I would like to. I have made a few improvements, like adjusting the play lengths of many metadata-less songs and revising the original atrocious design of the website using something called Twitter Bootstrap (and, wow, once you know what Bootstrap is, you start noticing it everywhere on the modern web). However, here are a few of the challenges that have slowed me down over the year :

  Problems With Native Client – Build System
  The technology which enables this project — Google’s Native Client (NaCl) — can be troublesome. One of my key frustrations with the environment is that every single revision of the NaCl SDK seems to adopt a completely new build system layout. If you want to port your NaCl project forward to newer revisions, you have to spend time wrapping your head around whatever the favored build system is. When I first investigated NaCl, I think it was using vanilla GNU Make. Then it switched to SCons. Then I forgot about NaCl for about a year and when I came back, the SDK had reverted back to GNU Make. While that has been consistent, the layout of the SDK sometimes changes and a different example Makefile shows the way.

  The very latest version of the API has required me to really overhaul the Makefile and to truly understand the zen of Makefile programming. I’m even starting to grasp the relationship it has to functional programming.

  Problems With Native Client – API Versions and Chrome Bugs
  I built the original Salty Game Music Player when NaCl API version 16 was current. By the time I published the v16 version, v19 was available. I made the effort to port forward (a few APIs had superfically changed, nothing too dramatic). However, when I would experiment with this new player, I would see intermittent problems on my Windows 7 desktop. Because of this, I was hesitant to make a new player release.

  Around the end of May, I started getting bug reports from site users that their Chrome browsers weren’t allowing them to activate the Salty Game Music Player — the upshot was that they couldn’t play music unless they manually flipped a setting in their browser configuration. It turns out that Chrome 27 introduced a bug that caused this problem. Not only that, but my player was one of only 2 known NaCl apps that used the problematic feature (the other was developed by the Google engineer who entered the bug).

  After feeling negligent for a long while about not doing anything to fix the bug, I made a concerted and creative effort to work around the bug and pushed out a new version of the player (based on API v25). My effort didn’t work and I had to roll it back somewhat (but still using the new player binaries). The bug was something that I couldn’t work around. However, at about the same time that I was attempting to do this, Google was rolling out Chrome 28 which fixed the bug, rendering my worry and effort moot.

  Problems With Native Client – Still Not In The Clear
  I felt reasonably secure about releasing the updated player since I couldn’t make my aforementioned problem occur on my Windows 7 setup anymore. I actually have a written test plan for this player, believe it or not. However, I quickly started receiving new bug reports from Windows users. Mostly, these are Windows 8 users. The player basically doesn’t work at all for them now. One user reports the problem on Windows 7 (and another on Windows 2008 Server, I think). But I can’t see it.

  I have a theory about what might be going wrong, but of course I’ll need to test it, and determine how to fix it.

  Database Difficulties
  The player is only half of the site ; the other half is the organization of music files. Working on this project has repeatedly reminded me of my fundamental lack of skill concerning databases. I have a ‘production’ database– now I’m afraid to do anything with it for fear of messing it up. It’s an an SQLite3 database, so it’s easy to make backups and to create a copy in order to test and debug a new script. Still, I feel like I’m missing an entire career path worth of database best practices.

  There is also the matter of ongoing database maintenance. There are graphical frontends for SQLite3 which make casual updates easier and obviate the need for anything more sophisticated (like a custom web app). However, I have a slightly more complicated database entry task that I fear will require, well, a custom web app in order to smoothly process hundreds, if not thousands of new song files (which have quirks which prohibit the easy mass processing I have been able to get away with so far).

  Going Forward
  I remain hopeful that I’ll gradually overcome these difficulties. I still love this project and I have received nothing but positive feedback over the past year (modulo the assorted recommendations that I port the entire player to pure JavaScript).

  You would think I would learn a lesson about building anything on top of a Google platform in the future, especially Native Client. Despite all this, I have another NaCl project planned.

• Cracking Aztec Game Audio

  7 juin 2011, par Multimedia Mike — Game Hacking

  Here’s a mild multimedia-related reverse engineering challenge for you. It’s pretty straightforward for those skilled in the art.

  The Setup
  One side effect of running this ridiculously niche interest blog at the intersection of multimedia, reverse engineering, and game hacking is that people occasionally contact me for assistance on those very matters. So it was when one of my MobyGames peers asked if I can help to extract some music from a game called Aztec Wars. The game consists of 2 discs, each with a music.xbe file that contains multiple tunes and is hundreds of megabytes large.

  
  
  

  That’s all the data I received from the first email. At first I’m wondering what makes people think I have some magical insight into cracking these formats with such little information. Ordinarily, I would need to have the entire data file to work with and possibly the game binaries. But I didn’t want to ask him to upload hundreds of megabytes of data and I didn’t feel like downloading it ; commitment issues and all.

  But then I gathered a little confidence and remembered that the .xbe files are probably just Game Resource Archive Formats (GRAF) which are, traditionally, absurdly simple. I asked my colleague to send me a hexdump of the first kilobyte of one of the .xbe GRAFs ('hexdump -C -n 1024 music.xbe > file') as well as the total file size of the GRAF.

  The Hexdump
  The first music.xbe file is 192817376 bytes large. These are the first 1024 144 bytes (more than enough) :

  00000000  01 00 00 00 60 04 00 00  14 00 00 00 01 00 00 00  |....`...........|
  00000010  0d 00 00 00 48 00 00 00  94 39 63 01 1c a4 21 03  |....H....9c..¤ !.|
  00000020  7a d2 54 04 04 28 ad 05  d8 88 fd 06 d8 88 fd 06  |zÒT..(­.Ø.ý.Ø.ý.|
  00000030  2a 6e 46 08 2a 6e 46 08  2a 6e 46 08 2a 6e 46 08  |*nF.*nF.*nF.*nF.|
  00000040  50 13 2f 0a e0 28 7e 0b  52 49 46 46 44 39 63 01  |P./.à( .RIFFD9c.|
  00000050  57 41 56 45 66 6d 74 20  10 00 00 00 01 00 02 00  |WAVEfmt ........|
  00000060  44 ac 00 00 10 b1 02 00  04 00 10 00 64 61 74 61  |D¬...±......data|
  00000070  fc 13 63 01 00 00 00 00  00 00 00 00 00 00 00 00  |ü.c.............|
  00000080  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
  

  The Challenge
  Armed with only the information in the foregoing section, figure out a method for extracting all the audio files in that file and advise on their playback/conversion. Ideally, this method should require minimal effort from both you and the person on the other end of the conversation.

  The Resolution
  The reason I ask is because I came up with a solution but knew, deep down, that there must be a slightly easier way. How would you solve this ?

  The music files in question are now preserved on YouTube (until they see fit to remove them for one reason or another).