Moving the horizontal track bar or using the arrow buttons chrashes the application

[Johndirr]

When using the horizontal track bar or the arrow buttons to navigate through the audio display the application crashes.

[protyposis]

This happens only with certain container formats (e.g., MKV, TS) and is related to FFmpeg seeking. The fix didn't make it into the last release due to QA issues, but will be rolled out when ready.

[protyposis]

Fix is out: https://github.com/protyposis/AudioAlign/releases/tag/v1.6.1

Please let me know if that resolves this issue.

[Johndirr]

The problem still exists in version 1.7. It happened with an MKV container. The audio inside the container is in AAC format.

[protyposis]

I unfortunately cannot reproduce, so this must be an issue with your specific file (there are many ways how an MKV container can be structured). Can you provide a sample file?

[Johndirr]

Sure. Here you go: Sample

[protyposis]

Thank you. Unfortunately, FFmpeg cannot precisely seek this file due to the way the audio frames are timestamped (the distance of the timestamps doesn't match the size of the frames), but AudioAlign requires frame-exact seeking.

As a quick fix, I'll force AudioAlign to generate wave proxy files for all containers that exhibit this behavior. Later, direct file access can probably be reintroduced by scanning through the file and building a seek index with corrected timestamps.

[protyposis]

the distance of the timestamps doesn't match the size of the frames

The reason for this is the low timescale resolution that FFmpeg uses for MKV (your sample file was encoded by FFmpeg 6.1): https://github.com/FFmpeg/FFmpeg/blob/e38092ef9395d7049f871ef4d5411eb410e283e0/libavformat/matroskaenc.c#L3430-L3431

Transcoding the container to MP4 fixes the timestamps: ffmpeg -i sample.mkv -c copy sample.mp4

[Johndirr]

Thank you. Unfortunately, FFmpeg cannot precisely seek this file due to the way the audio frames are timestamped (the distance of the timestamps doesn't match the size of the frames), but AudioAlign requires frame-exact seeking.

Will this be a problem when fingerprinting the file? Are the timestamps not corresponding to the actual audio frame then?

[protyposis]

Fingerprinting is unaffected - it doesn't use these timestamps.