Multimedia: FFMpeg

Streaming with FFMPEG

The simplest command line you can use to generate an RTP session composed by an audio stream and a video stream from an mp4 audio/video file is:

ffmpeg -re -i Videos/big_buck_bunny_720p_h264.mp4 \
-vcodec copy -an -f rtp rtp://192.168.1.4:9000 \
-vn -acodec copy -f rtp rtp://192.168.1.4:9002

Analysing this command line:

• “-re” is needed to stream the audio and the video at the correct rate (instead of streaming as fast as possible)
• “input.mpg” is the input file, to be streamed
• “-vcodec copy” and “-acodec copy” mean the audio and the video tracks will be streamed without re-encoding them
• “-f rtp” meand that the output format is RTP; we need one output stream for the video, and one for the audio. Hence, the first output has “-an” (no audio), the second output has “-vn” (no video)
• The output protocol is RTP, hence, the output file names are “rtp://:”

After you start the ffmpeg program, it will print something like

v=0
o=- 0 0 IN IP4 0.0.0.0
s=No Name
t=0 0
a=tool:libavformat 58.17.101
m=video 9000 RTP/AVP 96
c=IN IP4 192.168.1.4
b=AS:2972
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1; sprop-parameter-sets=J0IAH5WQBQBbsBEAESqIAzf5gOBAAC3GwABbja974O0OGSQ=,KM48gA==; profile-level-id=42001F
m=audio 9002 RTP/AVP 97
c=IN IP4 192.168.1.4
b=AS:188
a=rtpmap:97 MPEG4-GENERIC/48000/6
a=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3; config=11B0

You need to copy the SDP description (starting with “v=0”) in a .sdp file, that you will use to play the stream with vlc, ffplay, mplayer, or your favorite video player.

• FFmpeg Streaming Guide
• FFmpeg – the swiss army knife of Internet Streaming – part IV
• How can I generate a video file directly from an FFmpeg filter with no actual input file?
• Esempi d’utilizzo di ffmpeg e ffprobe
• Is sprop-parameter-sets or profile-level-id the SDP parameter required to decode H264?
• Using FFmpeg’s lavfi (libavfilter)

FFmpeg Docker containers

• FFmpeg Docker image (jrottenberg/ffmpeg) – based on Ubuntu, CentOS, Alpine
• Minimal FFmpeg Docker image built on Alpine Linux (opencoconut/ffmpeg)

Other FFMpeg  examples

• ffmpeg -f lavfi -i sine=f=220:b=4:d=5 -c:a libvorbis output.oga
• ffmpeg -f lavfi -i testsrc -f lavfi -i sine -t 10 -c:v libtheora -c:a libvorbis \
-q:v 5 -q:a 5 output.ogv
• ffmpeg -i http://archive.org/download/thethreeagesbusterkeaton/Buster.Keaton.The.Three.Ages.ogv -loop 0 -final_delay 500 -c:v gif -f gif -ss 00:01:20 -t 5 - > book_opening.gif

Streaming with VLC

VLC: Stream over UDP

http://www.jpsaman.org/sites/jpsaman.org/files/vlc-streaming-nluug.pdf