Recherche avancée

Sur d’autres sites (5332)

• FFmpeg output file format with no extension

  26 mars 2012, par Simone Margaritelli

  I'm developing a system which needs to store videos in the form :

  /path/to/video/<md5 of="of" the="the" file="file">
  
  </md5>

  So i do not have an output extension.
  I'm using ffmpeg to convert those videos, but it seems that it uses output file extension to determine the output format, so here's my problem.

  Due to the fact i don't have an output extension in file names, is there a way to specify the output format directly in the command line without create temporary files or dirty solutions like this ?

  Thanks

• DirectShow RTSP SourceFilter with MPEG-4 Video Stream

  5 octobre 2011, par 6.45.Vapuru

  I create a simple direct show source filter using FFmpeg.I read rtp packets from RTSP source and give them to decoder. It works for h264 stream.

  MyRtspSourceFilter[H264 Stream] ---> h264 Decoder --> Video Renderer

  The bad news is that it does not work for MPEG-4. I can able to connect my rtsp source filter with MPEG-Decoder. I got no exception but video renderer does not show anything. Actually just show one frame then nothing [just stop]... Decoders and Renderers are 3rd party so i can not debug them.

  MyRtspSourceFilter[MP4 Stream] ---> MPEG-4 Decoder --> Video Renderer

  I can able to get rtp packets from MPEG-4 RTSP Source using FFmpeg sucessfully.There is no problem with it.

  It seems that i have not set something(?) in my Rtsps Source
  Filter which is not necessary for H264 stream but may be important for
  MPEG-4 stream

  What may cause this h264 stream and MPEG-4 stream difference in a direct show rtsp source filter ? Any ideas.

  More Info :

  — First i try some other rtsp source filters for MPEG-4 Stream...Although my rtsp source is same i see different subtypes in their pin connections.

  — Secondly i realy get suspicious if the source is really MPEG-4 SO i check with FFmpeg...FFmpeg gives the source codec id as "CODEC_ID_MPEG4".

  Update :
  [ Hack ]

  I just set m_bmpInfo.biCompression = DWORD('xvid') it just worked fine...But it is static. How to dynamically get/determine this value using ffmpeg or other ways...

• Internecine Legal Threats

  1er juin 2011, par Multimedia Mike — Legal/Ethical

  FFmpeg and associated open source multimedia projects such as xine, MPlayer, and VLC have long had a rebel mystique about them ; a bunch of hackers playing fast and loose with IP law in order to give the world the free multimedia experience it deserved. We figured out the algorithms using any tools available, including the feared technique of binary reverse engineering. When I gave a presentation about FFmpeg at Linuxtag in 2007, I created this image illustrating said mystique :

  
  
  

  It garnered laughs. But I made the point that we multimedia hackers just press on, doing our thing while ignoring legal threats. The policy has historically worked out famously for us– to date, I seem to be the only person on the receiving end of a sort-of legal threat from the outside world.

  Who would have thought that the most credible legal threat to an open source multimedia project would emanate from a fork of that very project ? Because that’s exactly what has transpired :

  
  
  Click for full threat
  

  So it came to pass that Michael Niedermayer — the leader of the FFmpeg project — received a bona fide legal nastygram from Mans Rullgard, a representative of the FFmpeg-forked Libav project. The subject of dispute is a scorched-earth matter involving the somewhat iconic FFmpeg zigzag logo :

  Original 2D logo		enhanced 3D logo

  To think of all those years we spent worrying about legal threats from organizations outside the community. I’m reminded of that time-honored horror trope/urban legend staple : Get out ! The legal threats are coming from inside the house !

  I’m interested to see how this all plays out, particularly regarding jurisdiction, as we have a U.K. resident engaging an Italian lawyer outfit to deliver a legal threat to an Austrian citizen regarding an image hosted on a server in Hungary. I suspect I know why that law firm was chosen, but it’s still a curious jurisdictional setup.

  People often used to ask me if we multimedia hackers would get sued to death for doing what we do. My response was always, “There’s only one way to know for sure,” by which I meant that we would just have to engage in said shady activities and determine empirically if lawsuits resulted. So I’m a strong advocate for experimentation to push the limits. Kudos to Michael and Mans for volunteering to push the legal limits.