Sur d’autres sites (6374)

• mpegpsenc : show first SCR/DTS at debug level

  4 janvier 2013, par Michael Niedermayer

  mpegpsenc : show first SCR/DTS at debug level

• How to show audio bitrate information

  25 février 2014, par poc

  The ffmpeg only shows the video bitrate.How can I show the audio bitrate when I dump a streaming to file

  ffmpeg -i rtsp://172.19.1.40/live.sdp -acodec copy -vcodec copy export.avi

  

  

• 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 ?