ATH-MaaS/Pixelle-Video · error · RuntimeError

Failed to pad video: {error_msg}

Error message

Failed to pad video: {error_msg}

What it means

_pad_video_to_duration catches ffmpeg.Error from the padding step (extending the last frame or adding black frames to reach target duration) and re-raises RuntimeError with ffmpeg's stderr. It signals the ffmpeg pad filtergraph failed, distinct from the trim failure at the same call site.

Source

Thrown at pixelle_video/services/video.py:1003

                
                (
                    ffmpeg
                    .output(
                        video_stream,
                        output,
                        vcodec='libx264',
                        preset='fast',
                        crf=23
                    )
                    .overwrite_output()
                    .run(capture_stdout=True, capture_stderr=True, quiet=True)
                )
            
            return output
        except ffmpeg.Error as e:
            error_msg = e.stderr.decode() if e.stderr else str(e)
            logger.error(f"FFmpeg error padding video: {error_msg}")
            raise RuntimeError(f"Failed to pad video: {error_msg}")

View on GitHub (pinned to 848b054e4f)

Solutions

1. Inspect the stderr in the message for the specific filter/codec complaint
2. Try the other pad_strategy ('black' vs 'freeze') if one fails on this codec
3. Re-encode/normalize the input video to h264/yuv420p before padding
4. Verify target_duration > 0 and ffmpeg supports the required filters (`ffmpeg -filters | grep tpad`)

Example fix

// before
service._pad_video_to_duration('clip.mkv', 12.5, pad_strategy='freeze')
// after
service._pad_video_to_duration('clip.mkv', 12.5, pad_strategy='black')  # fallback strategy

import shutil

def ffmpeg_available() -> bool:
    return shutil.which('ffmpeg') is not None

def validate_pad_target(duration: float) -> float:
    if not (duration > 0):
        raise ValueError(f'target_duration must be positive: {duration}')
    return duration

try:
    padded = service._pad_video_to_duration(video, target, pad_strategy='freeze')
except RuntimeError:
    padded = service._pad_video_to_duration(video, target, pad_strategy='black')

When it happens

Trigger: merge_audio_video calls _pad_video_to_duration and ffmpeg fails: input codec/filter incompatibility with tpad or the freeze strategy, invalid target_duration (<= 0), unwritable output path, or missing ffmpeg binary.

Common situations: Videos with codecs the pad filter chain cannot handle (e.g. unusual pixel formats with 'freeze' strategy); duration values parsed from float rounding errors; ffmpeg build lacking needed filters.

Related errors

• Failed to trim video: {error_msg}
• Failed to concatenate videos: {error_msg}
• dashscope package not installed. Run: pip install dashscope
• HTML rendering failed: {type(e).__name__}: {e}
• API media service is not initialized

AI-assisted analysis of ATH-MaaS/Pixelle-Video@848b054e4f (2026-08-30). Data as JSON: /api/errors/004a31268a4edea4. Report an issue: GitHub.