关于MPEG-TS文件起始时间不一致的技术咨询

Hey there, great question—this is a super common quirk when working with Wowza Streaming Engine and MPEG-TS outputs, and you’re absolutely on the right track suspecting the source plays a role! Let’s break down the key factors that could be causing this:

• Source file timecode metadata
  Most of the time, non-zero start times in your downloaded TS files trace back to the original source video (like MP4, MOV, or ProRes files). Many professional cameras or editing tools set a non-zero starting timecode (e.g., to sync with other footage in a project), and Wowza often preserves this metadata when packaging the stream into MPEG-TS. You can verify this quickly with a tool like ffprobe—run this command on your source file to check its start time:

  ffprobe -show_entries stream=start_time,time_base -i your-source-video.mp4
  

  If the start_time value isn’t 0, that’s almost certainly the root cause.

• Wowza’s timecode handling settings
  Even if your source has a non-zero start time, you can configure Wowza to reset the timecode during packaging. Head to your Wowza application’s transcoder or VOD stream settings and look for the "Timecode Handling" option—if it’s set to "Preserve", it’ll keep the source’s original timecode. Switching it to "Reset" will force the TS file’s start time to 0. Also, double-check any custom transcoder templates you’re using; some might override this default behavior.

• How you’re downloading the TS files
  If you’re capturing the stream as if it were live (e.g., using a screen recorder or network sniffer) instead of pulling the pre-packaged VOD segments via Wowza’s HLS/DASH manifests, the start time might be tied to when you initiated the download rather than the source’s actual start. Make sure you’re using the manifest URLs Wowza generates for your VOD content to grab the properly segmented TS files directly.

• Source file gaps or corrupted timecode
  In rare cases, if your source video has gaps in its timecode (from editing or truncation), Wowza might adjust the start time to avoid playback issues. Running a quick re-encode of the source file to fix any timecode inconsistencies can resolve this.

To sum it up: Start by checking your source file’s timecode with ffprobe. If that’s non-zero, either re-encode the source to reset its start time, or tweak Wowza’s timecode handling settings to override it during packaging.

备注：内容来源于stack exchange，提问作者enriquedc04