FFmpeg 手动启动但不随 Systemd 一起启动

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FFmpeg 手动启动但不随 Systemd 一起启动

eKr*_*nak 5 linux ffmpeg alsa raspberry-pi systemd

在带有官方 Debian 10 映像的 Raspberry Pi 4 B 4GB 上，我有 /home/pi/run.sh 脚本，其中包含以下内容：

#!/bin/bash
ffmpeg -nostdin -framerate 15 -video_size 1280x720 -input_format yuyv422  -i /dev/video0 -f alsa -i hw:Device \
    -af acompressor=threshold=-14dB:ratio=9:attack=10:release=1000 -c:a aac -ac 2 -ar 48000 -ab 160k \
    -c:v libx264 -pix_fmt yuv420p -b:v 3M -bf 1 -g 20 -flags +ilme+ildct -preset ultrafast \
    -streamid 0:0x101 -streamid 1:0x100 -mpegts_pmt_start_pid 4096 -mpegts_start_pid 0x259 -metadata:s:a:0 language="" -mpegts_service_id 131 -mpegts_transport_stream_id 9217 -metadata provider_name="Doesnt matter" -metadata service_name="Doesnt matter" \
    -minrate 3500 -maxrate 3500k -bufsize 4500k -muxrate 4000k  -f mpegts "udp://@239.1.67.13:1234?pkt_size=1316&bitrate=4000000&dscp=34" -loglevel debug < /dev/null > /tmp/ff3.log 2>&1

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脚本从控制台启动没有问题。它从 USB 声卡获取音频，从 USB 摄像头获取视频，并创建 UDP 流到 IPTV。然后我创建了 Systemd 服务：

[Unit]
Description=Streamer
After=multi-user.target sound.target network.target

[Service]
ExecStart=/home/pi/run.sh
KillMode=control-group
Restart=on-failure
TimeoutSec=1

[Install]
WantedBy=multi-user.target
Alias=streaming.service

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重新启动 Raspberry 后，脚本已启动，但 FFmpeg 因日志中的错误失败而挂起：

cur_dts is invalid st:0 (257) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:1 (256) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (257) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:1 (256) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (257) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:1 (256) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:0 (257) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
cur_dts is invalid st:1 (256) [init:1 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)

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并且不会开始流式传输到 UDP 目标。但是，如果我手动登录 SSH 并发出systemctl stop Streaming，然后systemctl start Streaming， Ffmpeg 会成功启动。开机自动启动服务有什么不同？

在脚本请求时设置“睡眠超时”不会有帮助。然而，从 FFmpeg 配置中删除音频流似乎可以解决启动时自动启动的问题。