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• ffmpeg & png watermark issue

  2 décembre 2013, par mindcast

  I tried to create a watermark (using a png image) on a video like this :

  ffmpeg -i test.wmv -b:a 300k -ar 22050 -t 10 -f flv -s 352x288 -vf "movie = watermark_logo352.png [watermark]; [in][watermark] overlay =0:0 [out]" out.flv

  but I get the error :

  ffmpeg version 0.10.4 Copyright (c) 2000-2012 the FFmpeg developers
  
  built on Jun 14 2012 13:14:31 with gcc 4.4.5   configuration:
  
  --prefix=/home/username --enable-cross-compile --enable-shared --arch=amd64 --target-os=linux --disable-yasm --enable-decoder=png --enable-encoder=png   
  
          libavutil      51. 35.100 / 51. 35.100   
  
          libavcodec     53. 61.100 / 53. 61.100   
  
          libavformat    53. 32.100 / 53. 32.100   
  
          libavdevice    53.  4.100 / 53.  4.100   
  
          libavfilter     2. 61.100 /  2. 61.100   
  
          libswscale      2.  1.100 /  2.  1.100   
  
          libswresample   0.  6.100 /  0.  6.100 
  
          Input #0, asf, from 'test.wmv':   
  
          Metadata:
  
              >     WMFSDKVersion   : 9.00.00.2980
  
              >     WMFSDKNeeded    : 0.0.0.0000
  
              >     IsVBR           : 1
  
              >     VBR Peak        : 351
  
              >     Buffer Average  : 728   Duration: 00:00:05.59, start: 0.000000, bitrate: 574 kb/s
  
              >     Stream #0:0(jpn): Audio: wmav2 (a[1][0][0] / 0x0161), 22050 Hz, 2 channels, s16, 32 kb/s
  
              >     Stream #0:1(jpn): Video: wmv1 (WMV1 / 0x31564D57), yuv420p, 352x288, 520 kb/s, SAR 8:9 DAR 88:81, 29.97 tbr, 1k tbn, 1k tbc File
  
              > 'out2.flv' already exists. Overwrite ? [y/N] y w:352 h:288
  
              > pixfmt:yuv420p tb:1/1000000 sar:8/9 sws_param: 
  
      [image2 @ 0x551f880] decoding for stream 0 failed 
  
      [image2 @ 0x551f880] Could not find codec parameters (Video: png) 
  
      [movie @ 0x551f440] Failed to find stream info
  
      [movie @ 0x551f440] Failed to find any codec 
  
      Error initializing filter 'movie' with args 'watermark_logo352.png' 
  
      Error opening filters!

  When I use a jpg, it works like a charm.

  I'm use ffmpeg v 0.10.4 on Debian 6 Squeeze.
  Any help would be much appreciated.

  EDIT

  The problem is simpler than i thought. If i use ffmpeg -i with any png image i get a similar error :

    libavutil      51. 35.100 / 51. 35.100
  
    libavcodec     53. 61.100 / 53. 61.100
  
    libavformat    53. 32.100 / 53. 32.100
  
    libavdevice    53.  4.100 / 53.  4.100
  
    libavfilter     2. 61.100 /  2. 61.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0.  6.100 /  0.  6.100
  
    libpostproc    52.  0.100 / 52.  0.100
  
  [image2 @ 0xc8b73a0] decoding for stream 0 failed
  
  [image2 @ 0xc8b73a0] Could not find codec parameters (Video: png)
  
  watermark.png: could not find codec parameters

• Alias Artifacts

  26 avril 2013, par Multimedia Mike — General

  Throughout my own life, I have often observed that my own sense of nostalgia has a window that stretches about 10-15 years past from the current moment. Earlier this year, I discovered the show “Alias” and watched through the entire series thanks to Amazon Prime Instant Video (to be fair, I sort of skimmed the fifth and final season which I found to be horribly dull, or maybe franchise fatigue had set in). The show originally aired from 2001-2006 so I found that it fit well within the aforementioned nostalgia window.

  
  
  

  But what was it, exactly, about the show that triggered nostalgia ? The computers, of course ! The show revolved around spies and espionage and cutting-edge technology necessarily played a role. The production designer for the series must have decided that Unix/Linux == awesome hacking and so many screenshots featured Linux.

  Since this is still nominally a multimedia blog, I’ll start of the screenshot recon with an old multimedia player. Here is a vintage Mac OS desktop running an ancient web browser (probably Netscape) that’s playing a full-window video (probably QuickTime embedded directly into the browser).

  
  

  

  Click for larger image

  
  

  Let’s jump right into the Linux side of things. This screenshot makes me particularly sentimental since this is exactly what a stock Linux/KDE desktop looked like circa 2001-2003 and is more or less what I would have worked with on my home computer at the time :

  
  

  

  Click for larger image

  
  

  Studying that screenshot, we see that the user logs in as root, even to the desktop environment. Poor security practice ; I would expect better from a bunch of spooks.

  Echelon
  Look at the terminal output in the above screenshot– it’s building a program named Echelon, an omniscient spy tool inspired by a real-world surveillance network of the same name. In the show, Echelon is used to supply plot-convenient intelligence. At one point, some antagonists get their hands on the Echelon source code and seek to compile it. When they do, they will have access to the vast surveillance network. If you know anything about how computers work, don’t think about that too hard.

  Anyway, it’s interesting to note that Echelon is a properly autotool’d program– when the bad guys finally got Echelon, installation was just a ‘make install’ command away. The compilation was very user-friendly, though, as it would pop up a nice dialog box showing build progress :

  
  

  

  Click for larger image

  
  

  Examining the build lines in both that screenshot and the following lines, we can see that Echelon cares about files such as common/db_err.c and bt_curadj.c :

  
  

  

  Click for larger image

  
  

  A little googling reveals that these files both belong to the Berkeley DB library. That works ; I can imagine a program like this leveraging various database packages.

  Computer Languages
  The Echelon source code stuff comes from episode 2.11 : “A Higher Echelon”. While one faction had gotten a hold of the actual Echelon source code, a rival faction had abducted the show’s resident uber-nerd and, learning that they didn’t actually receive the Echelon code, force the nerd to re-write Echelon from scratch. Which he then proceeds to do…

  
  

  

  Click for larger image

  
  

  The code he’s examining there appears to be C code that has something to do with joystick programming (JS_X_0, JS_Y_1, etc.). An eagle-eyed IMDb user contributed the trivia that he is looking at the file /usr/include/Linux/joystick.h.

  Getting back to the plot, how could the bad buys possibly expect him to re-write a hugely complex piece of software from scratch ? You might think this is the height of absurdity for a computer-oriented story. You’ll be pleased to know that the writers agreed with that assessment since, when the program was actually executed, it claimed to be Echelon, but that broke into a game of Pong (or some simple game). Suddenly, it makes perfect sense why the guy was looking at the joystick header file.

  This is the first bit of computer-oriented fun that I captured when I was watching the series :

  
  

  

  Click for larger image

  
  

  This printout purports to be a “mainframe log summary”. After some plot-advancing text about a security issue, it proceeds to dump out some Java source code.

  SSH
  Secure Shell (SSH) frequently showed up. Here’s a screenshot in which a verbose ‘ssh -v’ connection has just been closed, while a telnet command has apparently just been launched (evidenced by “Escape character is ‘^]’.”) :

  
  

  

  Click for larger image

  
  

  This is followed by some good old Hollywood Hacking in which a free-form database command is entered through any available command line interface :

  
  

  

  Click for larger image

  
  

  I don’t remember the episode details, but I’m pretty sure the output made perfect sense to the character typing the command. Here’s another screenshot where the SSH client pops up an extra-large GUI dialog element to notify the user that it’s currently negotiating with the host :

  
  

  

  Click for larger image

  
  

  Now that I look at that screenshot a little more closely, it appears to be a Win95/98 program. I wonder if there was an SSH client that actually popped up that gaudy dialog.

  There’s a lot of gibberish in this screenshot and I wish I had written down some details about what it represented according to the episode’s plot :

  
  

  

  Click for larger image

  
  

  It almost sounds like they were trying to break into a network computer. Analyzing MD5 structure… public key synthesized. To me, the funniest feature is the 7-digit public key. I’m a bit rusty on the math of the RSA cryptosystem, but intuitively, it seems that the public and private keys need to be of roughly equal lengths. I.e., the private key in this scenario would also be 7 digits long.

  Gadgets
  Various devices and gadgets were seen at various junctures in the show. Here’s a tablet computer from back when tablet computers seemed like fantastical (albeit stylus-requiring) devices– the Fujitsu Stylistic 2300 :

  
  

  

  Click for larger image

  
  

  Here’s a videophone from an episode that aired in 2005. The specific model is the Packet8 DV326 (MSRP of US$500). As you can see from the screenshot, it can do 384 kbps both down and up.

  
  

  

  Click for larger image

  
  

  I really regret not writing down the episode details surrounding this gadget. I just know that it was critical that the good guys get it and keep from falling into the hands of the bad guys.

  
  

  

  Click for larger image

  
  

  As you can see, the (presumably) deadly device contains a Samsung chip and a Lexar chip. I have to wonder what device the production crew salvaged this from (probably just an old cell phone).

  Other Programs

  The GIMP photo editor makes an appearance while scrubbing security camera footage, and serves as the magical Enhance Button (at least they slung around the term “gamma”) :

  
  

  

  Click for larger image

  
  

  I have no idea what MacOS-based audio editing program this is. Any ideas ?

  
  

  

  Click for larger image

  
  

  FTP shows up in episode 2.12, “The Getaway”. It’s described as a “secure channel” for communication, which is quite humorous to anyone versed in internet technology.

  
  

  

  Click for larger image

  
  

• Revision 458c2833c0 : Use saturated addition in SSSE3 of 32x32 quant The 32x32 forward transform can

  4 septembre 2013, par Jingning Han

  Changed Paths :
   Modify /vp9/common/vp9_rtcd_defs.sh

  
   Modify /vp9/encoder/vp9_quantize.c

  
   Modify /vp9/encoder/x86/vp9_quantize_ssse3.asm

  
  
  Use saturated addition in SSSE3 of 32x32 quant

  The 32x32 forward transform can potentially reach peak coefficient
  value close to 32700, while the rounding factor can go upto 610.
  This could cause overflow issue in the SSSE3 implementation of 32x32
  quantization process.

  This commit resolves this issue by replacing the addition operations
  with saturated addition operations in 32x32 block quantization.

  Change-Id : Id6b98996458e16c5b6241338ca113c332bef6e70