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• How to speed up thumbnail generation for video files using FFMPEG on MIPS

  6 juillet 2012, par Spottsworth

  I'm using the following command to get a thumbnail from a video file. It uses the seek option to grab a thumbnail. The problem is that this command takes up quite some time especially with certain containers such as MPEG-2 TS. (As much as 40 seconds). If I vary the point (duration) at which I want to grab the thumbnail , it does not seem to have an impact on the time taken. Of course when I run this on my Linux workstation, it hardly takes 2 seconds to produce the thumbnail. Any suggestions to speed up the process on my MIPS board ?

  ./ffmpeg -ss 18 -i input.ts -vf select='eq(pict_type\,PICT_TYPE_I)' -vframes 1 -an -s 150x100 thumb.jpg

• Qt browser plugin with Live555 and FFMPEG

  7 mars 2014, par user1047400

  I built a widget in Qt that play a rtsp audio/video stream with Live555 and FFMPEG.
  I works and now I want to include it inside a Qt BrowserPlugin.
  My plugin at the moment is able to start the RTSP session (i can see packets start to arrive from the camera) but an error occurs and plugin stops with an error.

  Could anyone say me anything about this kind of problem ?

  The only thing that Firefox says is "anomalous plugin crash". In practice it starts for some seconds and than crashs, even if with WireShark I can see that the RTSP session is started and packets are coming from the camera to my PC.

  My .pro file is :

  QT += core
  
  QT += gui
  
  QT += multimedia
  
  
  
  CONFIG   += console
  
  CONFIG   -= app_bundle
  
  TEMPLATE = app
  
  
  
  TARGET = pluginvs
  
  
  
  win32 {
  
  RC_FILE     = pluginvs.rc
  
  } else:mac {
  
  QMAKE_INFO_PLIST = Info.plist
  
  REZ_FILES += pluginvs.r
  
  rsrc_files.files = pluginvs.rsrc
  
  rsrc_files.path = Contents/Resources
  
  QMAKE_BUNDLE_DATA += rsrc_files
  
  }
  
  
  
  SOURCES += \
  
  virtualscreen.cpp \
  
  videosink.cpp \
  
  threadlistener.cpp \
  
  rtspmanager.cpp \
  
  livetaskscheduler.cpp \
  
  audiosink.cpp \
  
  audioplayer.cpp \
  
  pluginvs.cpp
  
  
  
  HEADERS += \
  
  virtualscreen.h \
  
  videosink.h \
  
  threadlistener.h \
  
  rtspmanager.h \
  
  livetaskscheduler.h \
  
  audiosink.h \
  
  audioplayer.h
  
  
  
  include(src/qtbrowserplugin.pri)
  
  
  
  
  
  # Requied for some C99 defines
  
  DEFINES += __STDC_CONSTANT_MACROS
  
  
  
  FFMPEG_ROOT = C:/dev/ffmpeg/ffmpeg-git-059707e-win32-dev
  
  FFMPEG_LIBRARY_PATH = $$FFMPEG_ROOT/lib
  
  FFMPEG_INCLUDE_PATH = $$FFMPEG_ROOT/include
  
  LIVE555_LIBRARY_PATH = C:/dev/live/
  
  
  
  LIBS += -L$$FFMPEG_LIBRARY_PATH \
  
  $$LIVE555_LIBRARY_PATH/BasicUsageEnvironment/libBasicUsageEnvironment.a \
  
  $$LIVE555_LIBRARY_PATH/groupsock/libgroupsock.a \
  
  $$LIVE555_LIBRARY_PATH/UsageEnvironment/libUsageEnvironment.a \
  
  $$LIVE555_LIBRARY_PATH/liveMedia/libliveMedia.a \
  
  C:/MinGW/lib/libws2_32.a \
  
  -lavutil \
  
  -lavcodec \
  
  -lavformat \
  
  -lswscale
  
  
  
  INCLUDEPATH += $$FFMPEG_INCLUDE_PATH \
  
  $$LIVE555_LIBRARY_PATH/liveMedia/include \
  
  $$LIVE555_LIBRARY_PATH/BasicUsageEnvironment/include \
  
  $$LIVE555_LIBRARY_PATH/groupsock/include \
  
  $$LIVE555_LIBRARY_PATH/UsageEnvironment/include

  Thank you
   Antonio

• Transcoding to webm with ffmpeg audio problems

  9 novembre 2011, par Max A.

  For the past few days, I have been trying to get my lossless .mov video(that has an audio track) to a .webm format.

  Some info on the video & audio is that the fps is 30. Also the audio track has about 3-5 seconds of silence/blank audio before you start hearing some music.

  My problem is that is seems during the transcoding to webm, it strips away this blank audio because when I go to play the video, the audio starts right away.I've also notice that it jumps right away to 4 seconds in the video. When i play it on the browser, it jumps to that moment in the timeline. If I try to scrub to the beginning, the video ends.

  I've have figured somethings out.

  1. This is just a webm problem. This does not happen with ogv or mp4
  2. It only happens if they is blank audio in the beginning of the audio track.

  I am using ffmpeg with the libvpx and libvorbis librarys and I am doing just the basic command line setup

  ffmpeg -i "infile" "outfile.webm"