WebRTC: Off-sync audio/video in DVR files #3993
Description
Describe the bug
In SRS Stack 5, enabling DVR with any settings (including default) for the default vhost results in off-sync audio/video files when trying to record WebRTC streams. The problem is especially conspicuous for small video fragments (10 sec or less).
Version
SRS Stack 5 (latest) via Docker: ossrs/srs-stack:5
To Reproduce
Steps to reproduce the behavior:
- Use the following bare-bones server config:
server_id srs-server;
listen 1935;
max_connections 1000;
daemon on;
disable_daemon_for_docker off;
utc_time on;
ff_log_dir /data/ffmpeg_logs;
rtc_server {
enabled on;
listen 8000;
candidate $CANDIDATE;
protocol udp;
reuseport 5;
use_auto_detect_network_ip off;
api_as_candidates off;
}
vhost __defaultVhost__ {
# General settings
tcp_nodelay on;
min_latency on;
# WebRTC
rtc {
enabled on;
nack on;
twcc on;
rtmp_to_rtc off;
rtc_to_rtmp on;
}
# Digital Video Recording
dvr {
enabled on;
dvr_apply all;
dvr_plan session;
dvr_path /data/record/[app]/[stream].[timestamp].mp4; # tried also ...flv, but no effect
dvr_wait_keyframe on;
time_jitter full; # full / zero
}
}- Create a WebRTC stream by publishing to
https://MY-HOST.com/rtc/v1/whip/?app=live&stream=100&secret=SRS_PUB_SECRET - Go to your DVR path (
/data/record/live) and download the resulting video(s), e.g.100.TIMESTAMP.mp4 - Observe off-sync audio/video.
- Replace
dvr_pathin config for.....flvand do steps 2-5 above. Same issue remains.
Expected behavior
Expected fully-sync DVR files (mp4 or flv), with no data loss.
Additional context
For small videos, 10 sec or less, even video data is often lossy: the resulting DVR files get frozen or scrambled, with audio completely off-sync.