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• ffmpeg - Stream webcam - RTP h264 + audio

  17 mai 2016, par Hossein

  I am trying to create a rtp stream using ffmpeg. I am taking input from my logitech C920 which has built in h264 encoding support and also has a microphone. I wanted to send both video(h264 either with the built in encoder or ffmpeg’s encoder) and audio(any encoding) through RTP and then play the stream using ffplay.

  So far I am able to send only the video with the following command :

  ffmpeg -i /dev/video0 -r 24 -video_size 320x240 -c:v libx264 -f  rtp rtp://127.0.0.1:9999

  and also the audio separately using the command :

  ffmpeg  -f alsa -i plughw:CARD=C920,DEV=0 -acodec libmp3lame -t 20 -f  rtp rtp://127.0.0.1:9998

  and play the sdp file with :

   ffplay -i -protocol_whitelist file,udp,rtp test3.sdp 
  
   ffplay -i -protocol_whitelist file,udp,rtp test4.sdp 

  I’m on Ubuntu 14.04

  How can I play the two streams with a single ffplay command as ffplay cannot take two inputs and I can’t send two streams using a single RTP stream(or can I ?).
  Also, how can I use the built in h264 encoder of my webcam ?

  Thank you !

• MoviePY write_videofile using GPU for faster encoding [closed]

  5 mai, par kaushal

  I'm creating a video from scratch using moviePY. I am generating all the required frames, adding required audio (including a voiceover and background music), adding a logo and finally writing the video file in 4K.

  


  Everything works fine, except the write_videofile takes a lot of time.

  


  I have read many related posts which mentions using the right codec etc. I have NVidia card, so tried both h264_nvenc and hevc_nvenc. Quality of the output video dropped with the first one, so I'm sticking to hevc_nvenc. I'm using below line to write the file.

  


          video_clip.write_videofile(targetfile, codec="hevc_nvenc", threads=32, fps=24)


  


  What I have noticed is, it does seem to be using the gpu, but very little. Compared to this, when I run stable diffusion or vegas rendering, it uses gpu a lot more.

  


  That's why I think there is definitely some scope of improvement here. If you see below screenshot, when the video file write starts, the gpu utilisation increases a tiny bit, but it can take a lot more I think, isn't it ?

  


  I can try various parameters that I've seen in other threads, like logger=None, progress_bar = False, ffmpeg_params=['-b:v','10000k'] etc., but they are not going to improve gpu utilisation in any shape or form. I've been wondering what am I missing.

  


  Any ideas or suggestions please ?

  


  

  


• Merging video and audio stream, where audio drifts

  22 avril 2015, par TL_IPD

  I want to record audio and video with my raspberry pi b+ 2.
  I tried to accomplish this with one ffmpeg command but this is to slow. and i could not get it working correctly

  I have a raspberry pi camera module and a Cirrus audio card. On the raspberry i have compiled a new kernel with support for the audio card. I also compiled ffmpeg on the raspberr with alsa support

  ~$ ffmpeg
  
  ffmpeg version N-71470-g2db24cf Copyright (c) 2000-2015 the FFmpeg developers
  
  built with gcc 4.6 (Debian 4.6.3-14+rpi1)
  
  configuration: --arch=armel --target-os=linux --enable-gpl --extra-libs=-lasound --enable-nonfree
  
    libavutil      54. 22.101 / 54. 22.101
  
    libavcodec     56. 34.100 / 56. 34.100
  
    libavformat    56. 30.100 / 56. 30.100
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 14.100 /  5. 14.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Hyper fast Audio and Video encoder
  
  usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

  Now i try to record an audio stream and a video stream ’at the same time’
  I do this my running a shell script

  raspivid -t 60000 -vs -w 1280 -h 720 -b 5000000 -fps 25 -o video.h264 &
  
  arecord -Dhw:sndrpiwsp -r 44100 -c 2 -d 60 -f S32_LE audio.aac

  i also tried with -r 22050 and -f S16_LE

  when running this it sometimes gives an (i think)

  overrun!!! (at least 1038.725 ms long)

  at the end of the script i have two files. a video and a audio file.

  now i want to merge those two together by using ffmpeg

  ffmpeg -i video.h264 -i audio.aac -c:v copy -c:a aac -strict experimental output.mp4

  this gives the output :

  ffmpeg version N-71470-g2db24cf Copyright (c) 2000-2015 the FFmpeg developers
  
  built with gcc 4.6 (Debian 4.6.3-14+rpi1)
  
  configuration: --arch=armel --target-os=linux --enable-gpl --extra-libs=-lasound --enable-nonfree
  
    libavutil      54. 22.101 / 54. 22.101
  
    libavcodec     56. 34.100 / 56. 34.100
  
    libavformat    56. 30.100 / 56. 30.100
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 14.100 /  5. 14.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, h264, from 'video_1min_3.h264':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: h264 (High), yuv420p, 1280x720, 25 fps, 25 tbr, 1200k tbn, 50 tbc
  
  Guessed Channel Layout for  Input Stream #1.0 : stereo
  
  Input #1, wav, from 'audio_1min_3.aac':
  
    Duration: 00:01:00.00, bitrate: 705 kb/s
  
      Stream #1:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 22050 Hz, 2 channels, s16, 705 kb/s
  
  [mp4 @ 0x3230f20] Codec for stream 0 does not use global headers but container format requires global headers
  
  Output #0, mp4, to 'output_1min_3.mp4':
  
    Metadata:
  
      encoder         : Lavf56.30.100
  
      Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1280x720, q=2-31, 25 fps, 25 tbr, 1200k tbn, 1200k tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 22050 Hz, stereo, fltp, 128 kb/s
  
      Metadata:
  
        encoder         : Lavc56.34.100 aac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #1:0 -> #0:1 (pcm_s16le (native) -> aac (native))
  
  Press [q] to stop, [?] for help
  
  frame= 1822 fps=310 q=-1.0 Lsize=   33269kB time=00:01:12.84 bitrate=3741.7kbits/s
  
  video:32300kB audio:941kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.086073%

  so finally i have a file output.mp4 that is a movie with audio that is in sync at the beginning but drifts away to a difference of about 4 seconds. where the audio is ahead of the video.

  I hope you can help me trying to solve this issue so the audio does not drift away anymore.

  Thanks in advance

  ( i tried to be as clear as possible )