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Version: 4.0 (Archived) 📦

Snapshot

SRS provides workaround for snapshots:

  1. HttpCallback: Use http callbacks to handle on_publish event to snapshot by FFMPEG, and to stop FFMPEG when got on_unpublish event.
  2. Transcoder: Use transcoder to snapshot.

HttpCallback​

This section describes how to use http callbacks to snapshot.

First, start the sample api server:

python research/api-server/server.py 8085

Second, write the config for SRS to snapshot:

# snapshot.conf
listen 1935;
max_connections 1000;
daemon off;
srs_log_tank console;
vhost __defaultVhost__ {
http_hooks {
enabled on;
on_publish http://127.0.0.1:8085/api/v1/snapshots;
on_unpublish http://127.0.0.1:8085/api/v1/snapshots;
}
ingest {
enabled on;
input {
type file;
url ./doc/source.flv;
}
ffmpeg ./objs/ffmpeg/bin/ffmpeg;
engine {
enabled off;
output rtmp://127.0.0.1:[port]/live?vhost=[vhost]/livestream;
}
}
}

Thrird, start SRS and the ingest will publish RTMP stream, which will trigger the on_publish event, then api will snapshot:

./objs/srs -c snapshot.conf

The snapshot generate thumbnails to directory:

winlin:srs winlin$ ls -lh research/api-server/static-dir/live/*.png
-rw-r--r-- 1 winlin staff 73K Oct 20 13:35 livestream-001.png
-rw-r--r-- 1 winlin staff 91K Oct 20 13:35 livestream-002.png
-rw-r--r-- 1 winlin staff 11K Oct 20 13:35 livestream-003.png
-rw-r--r-- 1 winlin staff 167K Oct 20 13:35 livestream-004.png
-rw-r--r-- 1 winlin staff 172K Oct 20 13:35 livestream-005.png
-rw-r--r-- 1 winlin staff 264K Oct 20 13:35 livestream-006.png
lrwxr-xr-x 1 winlin staff 105B Oct 20 13:35 livestream-best.png -> livestream-006.png

The thumbnail live-livestream-best.png will link to the big one to avoid blank image.

User can access it by http server: http://localhost:8085/live/livestream-best.png

Transcoder​

The transcoder can be used for snapshot:

listen              1935;
max_connections 1000;
daemon off;
srs_log_tank console;
vhost __defaultVhost__ {
transcode {
enabled on;
ffmpeg ./objs/ffmpeg/bin/ffmpeg;
engine snapshot {
enabled on;
iformat flv;
vfilter {
vf fps=1;
}
vcodec png;
vparams {
vframes 6;
}
acodec an;
oformat image2;
output ./objs/nginx/html/[app]/[stream]-%03d.png;
}
}
ingest {
enabled on;
input {
type file;
url ./doc/source.flv;
}
ffmpeg ./objs/ffmpeg/bin/ffmpeg;
engine {
enabled off;
output rtmp://127.0.0.1:[port]/live?vhost=[vhost]/livestream;
}
}
}

The thumbnails:

winlin:srs winlin$ ls -lh objs/nginx/html/live/*.png
-rw-r--r-- 1 winlin staff 265K Oct 20 14:52 livestream-001.png
-rw-r--r-- 1 winlin staff 265K Oct 20 14:52 livestream-002.png
-rw-r--r-- 1 winlin staff 287K Oct 20 14:52 livestream-003.png
-rw-r--r-- 1 winlin staff 235K Oct 20 14:52 livestream-004.png
-rw-r--r-- 1 winlin staff 315K Oct 20 14:52 livestream-005.png
-rw-r--r-- 1 winlin staff 405K Oct 20 14:52 livestream-006.png

Note: SRS never choose the best thumbnail.

Winlin 2015.10