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• FFMPEG terrible conversion quality when using -sameq (same quality as source) flag

  23 décembre 2011, par Brad

  I'm trying to convert .flv videos to .ogg format. After experimenting for a while, the ogg is always produced as very low quality. Even when I use the -sameq flag which essentially outputs the same bitrate, size, etc as the input file, the quality is substantially worse.

  Since I am pretty new with ffmpeg, does anyone know some good options to convert video files with maximum quality? I'm trying to preserve as much quality as possible which is why -sameq would be perfect, but it doesn't seem to work..

  Any help is appreciated :)

• how to read a http video stream with libavcodec (ffmpeg)

  23 décembre 2011, par mwahab

  I'm trying to read a real-time http video stream (I've set one up using VLC and my webcam) using libavcodec from ffmpeg. so far I've been able to read an mpeg file fine but when I pass a url instead of the file name it hangs (I assume it's waiting for the end of the file).

  anyone have experience/ideas on how to do this? I'm also open to alternatives if people have other suggestions.

  the end goal is to do live video-streaming on the iphone. apple's http live streaming has too much lag for what I need but that's for another post :)

  any help is greatly appreciated!

• Streaming Desktop using FFMPEG in windows [migrated]

  23 décembre 2011, par sonu thomas

  How to stream Desktop using FFMPEG in windows??

  I have tried ffmpeg -list_devices true -f dshow -i dummy

  and after that this to stream

  ffmpeg -f dshow  -i video="Chicony USB 2.0 Camera"  -r 30 -vcodec mpeg4 -q 12 -f mpegts        udp://192.168.2.7:6666?pkt_size=188?buffer_size=65535
  

  Using this i got to stream the Camera.

  What command i have to type to stream the Desktop in windows?

• FFMpeg compilation error "Undefined symbols for architecture x86_64"

  23 décembre 2011, par Saptarshi Biswas

  I am trying to compile ffmpeg (0.9.0.git) with x264(0.120) like this

  ./configure --enable-gpl --enable-libmp3lame \
     --enable-static --disable-shared --enable-libx264 \
     --enable-pthreads --disable-doc --enable-avfilter \
     --disable-ffplay --disable-ffserver --disable-ffprobe
  make
  

  and I encounter the following error:

  LD  ffmpeg_g
  Undefined symbols for architecture x86_64:
    "_MM_FIX_0_707106781", referenced from:
        _filter in libavfilter.a(vf_fspp.o)
    "_MM_FIX_0_541196100", referenced from:
        _filter in libavfilter.a(vf_fspp.o)
  ld: symbol(s) not found for architecture x86_64
  collect2: ld returned 1 exit status
  make: *** [ffmpeg_g] Error 1
  

  Any idea what the fix might be?

  Update: Might be unrelated but this discussion https://trac.macports.org/ticket/30093 says the issue was ffmpeg picking up llvm instead of gcc-4.2 but then this had already fixed in 0.7.4

• FFmpeg quality in PHP

  22 décembre 2011, par Psalms twnTysVn

  how to set an option using php code with regards of selecting the quality of the video/audio file. They can select either low or high quality then convert it to the selected quality type. Is there any code for that?