Overview

OBS Studio is a free and open source software for video recording and live streaming.

Quick manual on testing

1. For test we use:

• WCS server
• OBS Studio
• Player web application in Chrome browser to stream playback

2. Set up RTMP streaming to the server address, for example rtmp://test1.flashphoner.com:1935/live/, set the stream key obsStream:

3. Start streaming in OBS Studio:

4. Open Player application. Set the stream key in 'Stream' field and press 'Start' button. The stream captured playback begins.

Known issues

1. OBS Studio does no support KeepAlive.

Symptoms: disconnection occurs often while stream publishing with RTMP-encoder.

Solution: switch KeepAlive off for RTMP on the server using the following parameter in flashphoner.properties file

keep_alive.enabled=websocket,rtmfp

Since build 5.2.643 KeepAlive is turned off by default for RTMP publishers.

2. If RTMP stream is published from OBS using Nvidia GPU encoding, this stream may freeze when it is playing in Safari browser as WebRTC, or Safari browser may hang

Symptoms: stream playback freezes of browser hangs while playing RTMP stream as WebRTC in Safari browser

Solution: in OBS settings switch recording format from flv (by default) to mp4

3. If RTMP stream is published from OBS using QuickSync GPU encoding, P-frames contain SPS or PPS and considered to be keyframes

Symptoms: Error messages in client log like

11:29:56,151 ERROR H264AccessUnit - RTMP-pool-12-thread-23 Failed to get config, H264 can't generate AVC Config without sps/pps
11:29:56,151 ERROR H264AccessUnit - RTMP-pool-12-thread-23 Can't generate extradata, H264 can't generate extra data without sps/pps
11:29:56,151 INFO BitstreamNormalizer - RTMP-pool-12-thread-23 Add config in key frame
11:29:56,151 WARN BitstreamNormalizer - RTMP-pool-12-thread-23 Timing problem: Last received frame time 30758940; syncTime - 341766.
Current frame time - 30758940; syncTime - 341766; frame type - videoFrameKey

stream FPS is detected twice as much FPS defined in settings (for example, VIDEO_FPS: 60 while setting is 30)

Solution:

a) since build 5.2.627. set the following parameter

h264_strict_kframe_detect=true

b) for previous builds, disable QuickSync in OBS

4. RTMP connection is restored slowly on an unstable channel

Symptoms: when RTMP connection is closed by OBS due to a channel bad quality between OBS and server, the connection is not restored or is restored more than minute after the channel quality becomes good again

Solution: enable media activity control for RTMP publishing and reduce the activity control timeout to 10 seconds

flash_rtp_activity_enabled=true
rtp_activity_timeout=10