FFmpeg编码海康DVR无有效音轨视频时卡顿的问题求助

我有两台海康DVR（一台老旧模拟型号），用bash脚本通过FFmpeg获取指定时长的录像/直播流，用于Home Assistant移动告警存储。带音频的摄像头正常工作，但无有效音轨的摄像头会在接近指定时长时卡顿（旧设备卡在9.96秒，新设备卡在9.97秒），生成0KB文件。推测是时间戳缺失导致编码空音轨时卡住。

使用的FFmpeg命令 #

makejob=$(ffmpeg -fflags +genpts -y -ac 1 -channel_layout mono -rtsp_transport tcp -hide_banner -loglevel info -err_detect ignore_err -i  "rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/${camnumber}01?starttime=$starttime&endtime=$endTime" -map 0:v -map 0:a? -ar 44100 -filter:a "volume=$volume" -t $seconds -acodec aac -vcodec copy $filepathname)

场景日志 #

(A) 带音频摄像头（正常录制） #

Downloading from DVR BeB-DVR a 7 seconds video of the CAM CAMERA-1 recorded from 2023-08-19 10:10:10
Input #0, rtsp, from 'rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/101?starttime=20230819T101010Z&endtime=20230819T101020Z':
  Metadata:
    title           : HIK Media Server V4.32.116
    comment         : HIK Media Server Session Description : standard
  Duration: 462428:22:56.-75, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: h264 (Baseline), yuvj420p(pc, bt709, progressive), 1920x1080, 25 fps, 25 tbr, 90k tbn, 180k tbc
    Stream #0:1: Audio: pcm_mulaw, 8000 Hz, mono, s16, 64 kb/s
Output #0, mp4, to '/home/pi/hikdwn/downloaded/BeB-DVR-CAMERA-1-2023-08-19-h01010-(10s).mp4':
  Metadata:
    title           : HIK Media Server V4.32.116
    comment         : HIK Media Server Session Description : standard
    encoder         : Lavf57.56.101
    Stream #0:0: Video: h264 (Baseline) ([33][0][0][0] / 0x0021), yuvj420p(pc, bt709, progressive), 1920x1080, q=2-31, 25 fps, 25 tbr, 90k tbn, 90k tbc
    Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc57.64.101 aac
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (pcm_mulaw (native) -> aac (native))
Press [q] to stop, [?] for help
[mp4 @ 0x212a9d0] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
frame=  175 fps= 33 q=-1.0 Lsize=    1708kB time=00:00:07.00 bitrate=1998.8kbits/s speed=1.34x
video:1643kB audio:60kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.350157%
[aac @ 0x212cf00] Qavg: 111.884
Download completed!

(B) 无有效音轨摄像头（卡顿生成0KB文件） #

新DVR日志

Input #0, rtsp, from 'rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/501?starttime=20230819T101010Z&endtime=20230819T101020Z':
  Metadata:
    title           : HIK Media Server V4.32.116
    comment         : HIK Media Server Session Description : standard
  Duration: 462428:23:09.-90, start: 0.020000, bitrate: N/A
    Stream #0:0: Video: hevc (Main), yuv420p(tv), 2560x1440, 50 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1: Audio: pcm_mulaw, 8000 Hz, mono, s16, 64 kb/s
Output #0, mp4, to '/home/pi/hikdwn/downloaded/BeB-DVR-CAMERA-5-2023-08-19-h01010-(10s).mp4':
  Metadata:
    title           : HIK Media Server V4.32.116
    comment         : HIK Media Server Session Description : standard
    encoder         : Lavf57.56.101
    Stream #0:0: Video: hevc (Main) ([35][0][0][0] / 0x0023), yuv420p(tv), 2560x1440, q=2-31, 50 fps, 25 tbr, 90k tbn, 90k tbc
    Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc57.64.101 aac
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (pcm_mulaw (native) -> aac (native))
Press [q] to stop, [?] for help
frame=  251 fps=149 q=-1.0 size=       0kB time=00:00:09.97 bitrate=   0.0kbits/s speed=5.94x

旧DVR日志

Input #0, rtsp, from 'rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/501?starttime=20230819T101010Z&endtime=20230819T101020Z':
  Metadata:
    title           : HIK Media Server V3.1.4
    comment         : HIK Media Server Session Description : standard
  Duration: 97123:37:11.-81, start: 0.240000, bitrate: N/A
    Stream #0:0: Video: h264 (Baseline), yuv420p(progressive), 352x288, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1: Audio: pcm_mulaw, 8000 Hz, mono, s16, 64 kb/s
Output #0, mp4, to '/home/pi/hikdwn/downloaded/HomeDVR-VIALE-2023-08-19-h01010-(10s).mp4':
  Metadata:
    title           : HIK Media Server V3.1.4
    comment         : HIK Media Server Session Description : standard
    encoder         : Lavf57.56.101
    Stream #0:0: Video: h264 (Baseline) ([33][0][0][0] / 0x0021), yuv420p(progressive), 352x288, q=2-31, 25 fps, 25 tbr, 90k tbn, 90k tbc
    Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc57.64.101 aac
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (pcm_mulaw (native) -> aac (native))
Press [q] to stop, [?] for help
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 2, current: -17998; changing to 3. This may result in incorrect timestamps in the output file.
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 3, current: -14398; changing to 4. This may result in incorrect timestamps in the output file.
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 4, current: -10798; changing to 5. This may result in incorrect timestamps in the output file.
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 5, current: -7198; changing to 6. This may result in incorrect timestamps in the output file.
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 6, current: -3600; changing to 7. This may result in incorrect timestamps in the output file.
[mp4 @ 0x1377ce0] Non-monotonous DTS in output stream 0:0; previous: 7, current: 2; changing to 8. This may result in incorrect timestamps in the output file.
frame=  256 fps= 49 q=-1.0 size=       0kB time=00:00:09.96 bitrate=   0.0kbits/s speed=1.89x

问题分析 #

无有效音轨的摄像头，DVR依然返回了音轨流，但实际没有音频数据。FFmpeg尝试编码空音轨时，因时间戳异常导致卡顿无法完成封装，最终生成0KB文件。

解决方案 #

方案1：以最短流时长为准，避免空音轨卡住 #

添加-shortest参数，让FFmpeg自动以存在有效数据的流时长结束录制：

makejob=$(ffmpeg -fflags +genpts -y -ac 1 -channel_layout mono -rtsp_transport tcp -hide_banner -loglevel info -err_detect ignore_err -i  "rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/${camnumber}01?starttime=$starttime&endtime=$endTime" -map 0:v -map 0:a? -ar 44100 -filter:a "volume=$volume" -t $seconds -acodec aac -vcodec copy -shortest $filepathname)

方案2：强制禁用音频，仅录制视频 #

适合确定无音轨的摄像头，直接跳过音频处理：

makejob=$(ffmpeg -fflags +genpts -y -rtsp_transport tcp -hide_banner -loglevel info -err_detect ignore_err -i  "rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/${camnumber}01?starttime=$starttime&endtime=$endTime" -map 0:v -t $seconds -vcodec copy $filepathname)

方案3：增强错误处理，跳过损坏数据包 #

添加-fflags +discardcorrupt丢弃损坏数据包，-max_interleave_delta增大音视频交错阈值，缓解时间戳异常问题：

makejob=$(ffmpeg -fflags +genpts+discardcorrupt -y -ac 1 -channel_layout mono -rtsp_transport tcp -hide_banner -loglevel info -err_detect ignore_err -i  "rtsp://$user:$dvrpasswd@$dvraddress:554/ISAPI/streaming/tracks/${camnumber}01?starttime=$starttime&endtime=$endTime" -map 0:v -map 0:a? -ar 44100 -filter:a "volume=$volume" -t $seconds -acodec aac -vcodec copy -max_interleave_delta 1000000 $filepathname)

内容的提问来源于stack exchange，提问作者SkizZO