Issue
The video generation pipeline crashed with a KeyError: 'start' when accessing character timing information from WhisperX’s alignment output. This occurred during the character timing extraction phase, specifically when attempting to access char_info['start'] and char_info['end'] directly without validation. The error halted the entire video generation process, preventing completion.
Culprit
The system assumed all character alignment objects from WhisperX would contain the required 'start' and 'end' timing keys, but this was not always the case. The code lacked defensive programming practices, directly accessing these keys without checking for their presence. This led to crashes whenever a character alignment object lacked one of these critical timing fields.
Solution
Implemented defensive programming measures to ensure pipeline reliability:
- Input Validation: Added checks to verify the presence of
'start'and'end'keys before accessing them. - Graceful Degradation: Introduced a fallback mechanism to use word-level timing interpolation when character-level timing data is incomplete.
- Debug Visibility: Added warning messages to log problematic character objects, improving visibility into data quality issues.
- Status Reporting: Implemented debug output to indicate whether character-level or word-level timing was used for each segment.
This transformation prevents crashes and ensures the video generation pipeline can complete successfully, even with incomplete character timing data.