Record and Live-Stream simultaneously
ffmpeg -re -i ${INPUTFILE} -map 0 -flags +global_header -vf scale="1280:-1,format=yuv420p" -pix_fmt yuv420p -level 3.1 -vsync passthrough -crf 26 -g 50 -bufsize 3500k -maxrate 1800k -c:v libx264 -c:a aac -b:a 128000 -r:a 44100 -ac 2 -t ${STREAMDURATION} -f tee "[movflags=+faststart]${TARGETFILE}|[f=flv]${STREAMTARGET}"
- I use this script to stream to a RTMP target and record the stream locally as .mp4 with only one ffmpeg-instance.
- As input, I use
bmdcapture which is piped to ffmpeg. But it can also be used with a static videofile as input.
- The input will be scaled to 1280px width, maintaining height. Also the stream will stop after a given time (see
-t option.)
-
Note 1
- I recommend to use this inside a shell script. then you can define the variables ${INPUTFILE}, ${STREAMDURATION}, ${TARGETFILE}, ${STREAMTARGET}.
-
Note 2
- This is in daily use to live-stream a real-world TV show. No errors for nearly 4 years. Some parameters were found by trial-and-error or empiric testing. So suggestions / questions are welcome.
+
I use this script to stream to a RTMP target and record the stream locally as .mp4 with only one ffmpeg-instance.
+
As input, I use bmdcapture which is piped to ffmpeg. But it can also be used with a static videofile as input.
+
The input will be scaled to 1280px width, maintaining height. Also the stream will stop after a given time (see -t option.)
+
Notes
+
+ - I recommend to use this inside a shell script. then you can define the variables
${INPUTFILE}, ${STREAMDURATION}, ${TARGETFILE}, ${STREAMTARGET}.
+ - This is in daily use to live-stream a real-world TV show. No errors for nearly 4 years. Some parameters were found by trial-and-error or empiric testing. So suggestions / questions are welcome.
+
- - /usr/local/bin/ffmpeg
- starts the command
- - -re
- Read input at native framerate
- - -i input.mov
- The input file. Can also be a
- to use STDIN if you pipe in from webcam or SDI.
- - -map 0
- map ALL streams from input file to output
- - -flags +global_header
- Dont place extradata in every keyframe
- - -vf scale="1280:-1"
- Scale to 1280 width, maintain aspect ratio.
- - -pix_fmt yuv420p
- convert to 420p color space
- - -level 3.1
- H264 Level (defines some thresholds for bitrate)
- - -vsync passthrough
- Each frame is passed with its timestamp from the demuxer to the muxer.
- - -crf 26
- Constant rate factor - basically the quality
- - -g 50
- GOP size.
- - -bufsize 3500k
- Ratecontrol buffer size (~ maxrate x2)
- - -maxrate 1800k
- Maximum bit rate
- - -c:v libx264
- The video codec
- - -c:a aac
- The audio codec
- - -b:a 128000
- The audio bitrate
- - -r:a 44100
- The audio samplerate
- - -ac 2
- Two audio channels
- - -t ${STREAMDURATION}
- Time (in seconds) after which the stream should automatically end.
- - -f tee
- Use multiple outputs. Outputs defined below.
- - "[movflags=+faststart]target-file.mp4|[f=flv]rtmp://stream-url/stream-id"
- The output divided by pipe (|). First is local file. Second is Live Stream. Options for each target in square brackets before the target.
+ - ffmpeg
- starts the command
+ - -re
- Read input at native framerate
+ - -i input.mov
- The input file. Can also be a
- to use STDIN if you pipe in from webcam or SDI.
+ - -map 0
- map ALL streams from input file to output
+ - -flags +global_header
- Don't place extra data in every keyframe
+ - -vf scale="1280:-1"
- Scale to 1280 width, maintain aspect ratio.
+ - -pix_fmt yuv420p
- convert to 420p chroma subsampling scheme
+ - -level 3.1
- H264 Level (defines some thresholds for bitrate)
+ - -vsync passthrough
- Each frame is passed with its timestamp from the demuxer to the muxer.
+ - -crf 26
- Constant rate factor - basically the quality
+ - -g 50
- GOP size.
+ - -bufsize 3500k
- Ratecontrol buffer size (~ maxrate x2)
+ - -maxrate 1800k
- Maximum bit rate
+ - -c:v libx264
- encode output video stream using H.264
+ - -c:a aac
- encode output audio stream using AAC
+ - -b:a 128000
- The audio bitrate
+ - -r:a 44100
- The audio samplerate
+ - -ac 2
- Two audio channels
+ - -t ${STREAMDURATION}
- Time (in seconds) after which the stream should automatically end.
+ - -f tee
- Use multiple outputs. Outputs defined below.
+ - "[movflags=+faststart]target-file.mp4|[f=flv]rtmp://stream-url/stream-id"
- The output divided by pipe (|). First is local file. Second is Live Stream. Options for each target in square brackets before the target.