Sur d’autres sites (10283)

• Media viewer add on cannot convert wmv file in alfresco

  14 mai 2014, par sameer

  I am using Media Viewer add on to preview documents. For video files I am using FFMPEG as described in Media Viewer configuration page. It is able to convert for .avi files. But when I preview .wmv file it says could not load thumbnail list and the page is stuck. When I reload all I get is black screen and only volume is audible no video is available.

• Media Source Extension with an unfragmented mp4 file

  12 novembre 2015, par Matt

  I’m attempting to use media source extensions to play a mp4 file. The example that I’m following is here : http://html5-demos.appspot.com/static/media-source.html

  I have this example working with both webm videos, and fragmented mp4 videos. Do media source extensions not work with unfragmented mp4 videos ? Shouldn’t I be able to manually append chunks of the video to the source buffer ? It looks like the appending works, but the video won’t play.

• FFmpeg h264_v4l2m2m encoder changing aspect ratio from 16:9 to 1:1 with black bars

  8 janvier, par LycoReco2007

  When switching from libx264 to h264_v4l2m2m encoder in FFmpeg for YouTube streaming, the output video's aspect ratio changes from 16:9 to 1:1 with black bars on the sides, despite keeping the same resolution settings.

  


  Original working command (with libx264) :

  


  ffmpeg -f v4l2 \
    -input_format yuyv422 \
    -video_size 1280x720 \
    -framerate 30 \
    -i /dev/video0 \
    -f lavfi \
    -i anullsrc=r=44100:cl=stereo \
    -c:v libx264 \
    -preset ultrafast \
    -tune zerolatency \
    -b:v 2500k \
    -c:a aac \
    -b:a 128k \
    -ar 44100 \
    -f flv rtmp://a.rtmp.youtube.com/live2/[STREAM-KEY]


  


  When I replaced libx264 with h264_v4lm2m, it always produce a square resolution, and it automatically adds black bars to the top and the bottom of the sides of the camera. I currently using a Rasberry Pi 4 model B, with a webcam that I believe supports the 16:9 ratio (I've verified using v4l2-ctl --list-formats-ext -d /dev/video0 command)

  


  I've tried the follows :

  


  

  • Adding -aspect 16:9 parameter in the ffmpeg command

  


  • Adding video filters such as -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1"
None of these give me the correct aspect ratio.

  


  


  How can I make the h264_v4l2m2m encoder maintain the original 16:9 aspect ratio without adding black bars ? Is this a known limitation of the encoder, or am I missing some required parameters ?