ffstream

A drop-in replacement for ffmpeg that is tailored to live-streaming: it allows for dynamically changing encoding settings (e.g. bitrate).

The main use case this was implemented for is IRL streaming. For example:

• When the internet connection is of variable bandwidth: one may dynamically adjust the bitrate according to available channel.
• When the recoding equipment is overheating, it is possible to dynamically enable a pass-through (and disable recoding until the equipment would cool down).

But actually, if you got into using ffstream instead of ffmpeg you may want to consider writing yourown tool that is tailored for your needs by just using avpipeline directly.

How to use

This is supposed to be a kick-in replacement. So for example if you have:

ffmpeg -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1

you should be able to just replace ffmpeg with ffstream:

ffstream -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1

However, it won't work with various fancy functionality like filters, yet (to be implemented).

But since you switched to ffstream, now you can add flag -listen_control which would open a socket and listen for incoming requests live, e.g.:

ffstream -listen_control unix:/tmp/ffstream.sock -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1

After that you may use ffstreamctl to manage the actively running ffstream, for example:

<TBD>

Android

On Android it works based on Termux. If you already have Termux on your phone, then you can just build on your computer the tool:

make bin/ffstream-android-arm64.deb

(it will use Docker for that)

then install the deb file bin/ffstream-android-termux-arm64.deb in your Termux environment.

If you also need ffstreamctl then just build the static binary for normal Linux:

make bin/ffstreamctl-linux-arm64

and copy to /data/data/com.termux/files/usr/bin/ffstreamctl (it will be a static binary, so it works in any Linux environment)

But on the bright side when you succeed you get access to MediaCodec (hardware encoder) as well:

~ $ ffstream -encoders | grep mediacodec
00000000000000E2 av1_mediacodec
000000000000001B h264_mediacodec
00000000000000AD hevc_mediacodec
000000000000000C mpeg4_mediacodec
000000000000008B vp8_mediacodec
00000000000000A7 vp9_mediacodec

Debugging

For debugging, you may:

1. Add verbosity (e.g. with -v trace), e.g.:

ffstream -v trace -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1

2. Add the flag -listen_net_pprof, e.g.:

ffstream -v trace -listen_net_pprof 0.0.0.0:12345 -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1

This allows to debug the app as any other Go app, e.g.:

curl http://127.0.0.1:12345/debug/pprof/goroutine?debug=1 | less

3. Collect all logs to a centralized logging server (for investigating rarely occurring problems), e.g.:

ffstream -v trace -logstash_addr udp://my.logstash.server:9600 -sentry_dsn https://my.sentry.server/URI -i rtmp://127.0.0.1:1937/test/stream0 -c:v libx264 -f flv rtmp://127.0.0.1:1937/test/stream1