启动live555HLSProxy实现RTSP转HLS遇‘无可用子会话’错误

Let's break down why you're hitting this error and walk through fixes step by step:

First off, that error means live555HLSProxy can't detect valid audio/video subsessions (tracks) in your RTSP stream—even though ffplay can play it, the HLS proxy has stricter compatibility rules for HLS standards. Here's how to diagnose and fix this:

• Double-check your RTSP URL for typos
  Wait a minute—you said ffplay works with rtsp://192.168.1.2:8554/test.mpeg, but you’re passing rtsp://192.168.1.136:8554/test.mpg to the proxy. The IP addresses don’t match, and the file extensions differ (.mpeg vs .mpg). Make sure you’re using the exact same URL that ffplay successfully plays—this is a super common easy fix.

• Verify your stream’s codec compatibility
  live555HLSProxy requires HLS-friendly codecs:

  • Video: H.264 (MPEG-4 AVC)
  • Audio: AAC (MP3 works in some cases, but AAC is preferred)
    Use ffprobe to check your stream’s codecs:

  ffprobe rtsp://192.168.1.2:8554/test.mpeg
  

  Look for codec_name under the video and audio streams. If you see something like MPEG-2 video or PCM audio, live555 won’t recognize these as usable subsessions for HLS.

• Inspect the stream’s SDP metadata
  Sometimes the RTSP server’s SDP (Session Description Protocol) might be malformed or missing track info that live555 expects. Use rtspdump to grab the SDP:

  rtspdump -d rtsp://192.168.1.2:8554/test.mpeg
  

  Look for lines starting with m=video and m=audio—these should list the codec types and ports. If either track is missing, or the codec isn’t in live555’s supported list, that’s the root issue.

• Force subsession selection (if supported)
  Try running the proxy with verbose output to see more details about detected subsessions:

  /path/to/live555HLSProxy -v "rtsp://192.168.1.2:8554/test.mpeg" test_stream
  

  Some versions of live555HLSProxy let you manually specify video/audio tracks with -v <track number> or -a <track number>—check the help docs with /path/to/live555HLSProxy -h for available flags.

• Transcode the stream if codecs are incompatible
  If your original stream uses non-HLS codecs, use FFmpeg to transcode it to H.264+AAC first, then push it to your live555MediaServer:

  ffmpeg -i rtsp://192.168.1.2:8554/test.mpeg -c:v libx264 -preset fast -c:a aac -f rtsp rtsp://192.168.1.2:8554/hls_compatible_stream
  

  Then point the live555HLSProxy to this new transcoded stream:

  /path/to/live555HLSProxy "rtsp://192.168.1.2:8554/hls_compatible_stream" test_stream
  

内容的提问来源于stack exchange，提问作者marmeladze