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• FFMPEG on Windows faststart command line with or without a +

  24 juillet 2014, par C0nw0nk

  So on the following wiki page i see ffmpeg tells us when using faststart for HTML5 compatibility we should use a + symbol.

  https://trac.ffmpeg.org/wiki/Encode/H.264#faststartforwebvideo

  -movflags +faststart

  But looking at command line examples on here and other sites everyone puts it in their command line like this.

  ffmpeg -i C:\vidtests\Wildlife.mp4 -movflags faststart C:\vidtests\Wildlife_fs.mp4

  So my question is should it matter if the + symbol is there or not ?

• FFmpeg : Read profile level information from mp4

  31 mars 2016, par Martin

  I have a mp4 file and need the profile level of it. FFmpeg says, it has baseline profile, which is what I need, but I need also the level.

  Here is what I get from FFmpeg :

  ffmpeg version 0.8, Copyright (c) 2000-2011 the FFmpeg developers
  
    built on Jul 20 2011 13:32:19 with gcc 4.4.3
  
    configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-libfaac --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264
  
    libavutil    51.  9. 1 / 51.  9. 1
  
    libavcodec   53.  7. 0 / 53.  7. 0
  
    libavformat  53.  4. 0 / 53.  4. 0
  
    libavdevice  53.  1. 1 / 53.  1. 1
  
    libavfilter   2. 23. 0 /  2. 23. 0
  
    libswscale    2.  0. 0 /  2.  0. 0
  
    libpostproc  51.  2. 0 / 51.  2. 0
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test-show.mp4':
  
    Metadata:
  
      major_brand     : f4v 
  
      minor_version   : 0
  
      compatible_brands: isommp42m4v 
  
      creation_time   : 2012-03-21 16:00:00
  
    Duration: 00:56:07.40, start: 0.000000, bitrate: 2004 kb/s
  
      Stream #0.0(eng): Video: h264 (Baseline), yuv420p, 854x480 [PAR 1:1 DAR 427:240], 1904 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
  
      Metadata:
  
        creation_time   : 2012-03-21 16:00:00
  
      Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16, 96 kb/s
  
      Metadata:
  
        creation_time   : 2012-03-21 16:00:00
  
  At least one output file must be specified

  Is there any option other than -i I can use to get the level information ?

• Solving The XVD Puzzle

  15 avril 2012, par Multimedia Mike — General, multimedi archaeology, silicon valley, vg2, xvd, zygo

  I downloaded a multimedia file a long time ago (at least, I strongly suspected it was a multimedia file which is why I downloaded it). It went by the name of ‘lamborghini_850kbps.vg2′. I have had it in my collection for at least 7 years. I couldn’t remember where I found it. I downloaded it before it occurred to me to take notes about this sort of stuff.

  I found myself staring at the file again today and Googled the filename. This led me to a few Japanese sites which also contained working URLs for a few more .vg2 samples. Some other clues led me to a Russian language forum where someone had linked to a site that had Win32 codec modules that could process the files. The site was defunct but the Internet Archive Wayback Machine kept a copy for me, as well as copies of several more .vg2 samples from a defunct Japanese site previously involved with this codec.

  Sometimes this internet technology works really well. But I digress.

  Anyway, through all this, I finally found a clue : XVD. and wouldn’t you know, there is already a basic page on the MultimediaWiki describing the technology. In fact, while VG2 is a custom container, the MultimediaWiki states that the video component has a FourCC of VGMV, and there is already a file named VGMV.avi in the root V-codecs/ samples directory, something I vow to correct (that’s a big pet peeve of mine– putting samples in the root V-codecs/ or A-codecs/ directories).

  XVD… XVD… XVD… why does that sound so familiar ? Oh, of course ; there is a company named XVD and they have an office in the Bay Area which I have passed on numerous occasions, like this morning :

  
  <

  Someone originally connected with the multimedia technology in question operates a website which contains an unofficial history of the XVD tech. At first, I was wondering if the technology was completely defunct (and should therefore be open sourced). But if XVD’s solutions page (dated 2010) is to be believed, the technology is still in service, and purported to be better than H.264 and VC-1 : “The current generation of XVD video compression technology provides better video quality at any given data rate than standards-based codecs (H.264 or VC-1) with four times lower encoding complexity (when compared with H.264 Main Profile).”

  If they say so. For my part, I’m just happy that I have finally figured out what this lamborghini_850kbps.vg2 is so that I can properly catalog it on the samples site, which I have now done, along with other samples and various codecs modules.

  This episode reminds me that there’s a branch office of Zygo Corporation close to my home (though the headquarters are far, far away). The companies you see in Silicon Valley. Anyway, long-time open source multimedia hackers will no doubt recognize Zygo from the ZyGo FourCC & video codec transported in QuickTime files that was almost decode-able using an H.263 decoder.

  
  
  

  I may never learn what Zygo’s core competency actually is, but I will always remember their multimedia tech every time I run past their office.