Recherche avancée

Sur d’autres sites (8830)

• Gstreamer, x264enc "Redistribute latency..." error

  20 août 2021, par Jason

  I'm trying to setup a video pipeline with very limited bandwidth. I was able to do it with two raspberry pis using the below lines. The first is for the camera pi and the second is to watch stream :

  


  gst-launch-1.0 rpicamsrc preview=false !  'video/x-h264, width=800, height=600, framerate=30/1' ! h264parse ! rtph264pay config-interval=1 pt=96 ! gdppay ! udpsink host=YOUR_PC_IP port=5000
gst-launch-1.0 udpsrc port=5000 ! gdpdepay ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink sync=false


  


  It works but I go over my bandwidth limit if there is movement. I'm not sure if there is a way to limit bandwidth by setting a parameter here :

  


  'video/x-h264, width=800, height=600, framerate=30/1'


  


  From what I can find online, I have to use something like x264enc. I've followed tutorials but I can't get x264enc to work. it always outputs "Redistribute latency..." on both machines when run and it stays there.

  


  I've tried using x264enc like follows :

  


  gst-launch-1.0 rpicamsrc preview=false !  'video/x-raw, width=800, height=600, framerate=30/1' ! x264enc ! h264parse ! rtph264pay config-interval=1 pt=96 ! gdppay ! udpsink host=YOUR_PC_IP port=5000
gst-launch-1.0 rpicamsrc preview=false !  'video/x-raw, width=800, height=600, framerate=30/1' ! x264enc tune=zerolatency ! h264parse ! rtph264pay config-interval=1 pt=96 ! gdppay ! udpsink host=YOUR_PC_IP port=5000
gst-launch-1.0 rpicamsrc preview=false ! x264enc ! h264parse ! rtph264pay config-interval=1 pt=96 ! gdppay ! udpsink host=YOUR_PC_IP port=5000
gst-launch-1.0 rpicamsrc preview=false ! x264enc tune=zerolatency ! h264parse ! rtph264pay config-interval=1 pt=96 ! gdppay ! udpsink host=YOUR_PC_IP port=5000


  


  Based on tutorials, I would think some of those should work. Other threads say that tune=zerolatency fixes my problem. At least the ones with same output of "Redistribute latency..." I don't know what I'm doing wrong.

  


  Any help would be appreciated. Thanks !

  


• gcc "relocation R_X86_64_PC32 against symbol `ff_M24A'" error when linking statically against ffmpeg on linux

  15 juillet 2021, par YB_Evil

  I am trying to build a JNI shared library which statically links to ffmpeg.

  



  But at the linking stage, gcc fails with the following error :

  



  /usr/bin/ld: ./lib_lin64/libswscale.a(swscale.o): relocation R_X86_64_PC32 against symbol `ff_M24A' can not be used when making a shared object; recompile with -fPIC


  



  I am using the following commands to compile my jni library :

  



  gcc -I $JAVA_HOME/include -I $JAVA_HOME/include/linux -I ./include -fPIC -c *.c
  
gcc -shared -Wl,--no-undefined -o libnv_avc_dec.so *.o -Wl,-Bstatic -L./lib_lin64 -lavcodec -lavutil -lswresample -lswscale -Wl,-Bdynamic -lm


  



  And I only use h264 decoding feature, so I am also building ffmpeg from source with the minimal required feature set. The ./configure command I use is :

  



  ./configure \
--enable-pic --prefix=ffmpeg-dist \
--disable-debug --enable-version3 --enable-gpl \
--disable-everything --enable-hwaccel=h264_vdpau --enable-hwaccel=h264_vaapi --enable-hwaccel=h264_qsv --enable-hwaccel=h264_mmal \
--enable-decoder=h264 --enable-decoder=h264_vdpau --enable-decoder=h264_crystalhd --enable-decoder=h264_mmal --enable-decoder=h264_qsv \
--disable-iconv --disable-securetransport --disable-xlib --disable-zlib --disable-lzma  --disable-bzlib  --disable-doc --disable-programs --disable-avformat --disable-avfilter --disable-postproc


  



  So, as I understand, the linker tells me that ffmpeg should be compiled with -fPIC flag in order to make a shared library. But I believe that I've already done so by specifying the —enable-pic configure flag. And I am pretty much stuck here because I am not very familiar with autotools, nor with ffmpeg build process in particular.

  



  If this is the issue of ffmpeg .a libs not being compiled with -fPIC flag, how can i force it ? And if this is not the case, what am i doing wrong and how can i fix this error ?

  



  Environment details : Ubuntu 14.04.3 64-bit in Virtualbox, gcc 4.8.5 and 5.3 (both give the same results), ffmpeg v.2.8.5

  


• Getting a "memory access out of bounds" error while concatenating multiple videos with @mmfpeg React

  1er juillet 2021, par Bilal Mohammed

  I'm trying to concatenate multiple videos with react using @ffmpeg. I tried creating a GIF from the video, and it's working fine, but I'm not having luck with video concatenation. I'm getting a "memory access out of bounds" error. Have no idea what can go wrong here.
Any help will be appreciated.

  


  const mergeVideos = async () =>

  


  let myFile = ''

for (let i = 0; i < video.length; i++) {
  myFile += `file ${ await fetchFile(video[i]) }`

}
ffmpeg.FS('writeFile', 'MyList.txt', myFile);

await ffmpeg.run('-f','concat', '-safe',0, '-i', 'MyList.txt', '-codec','-c',  'output.mp4');

// Read the result
 data = ffmpeg.FS('readFile', 'output.mp4');

// Create a URL
const url = URL.createObjectURL(new Blob([data.buffer], { type: 'video/mp4'}));

setMergedVideos(url)