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https://issues.apache.org/jira/browse/TIKA-4777?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18096400#comment-18096400
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ASF GitHub Bot commented on TIKA-4777:
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dschmidt commented on PR #2936:
URL: https://github.com/apache/tika/pull/2936#issuecomment-4978296729
Went with `quicktime:` after looking at precedent: ExifTool, exiv2 and
metadata-extractor all spell out "QuickTime" for this group, none abbreviate to
qt, and the abbreviation reads like the C++ framework to me. `video:` would be
wrong anyway since these keys live at container level and audio-only .m4a files
carry them too (Voice Memos write QuickTime atoms). So the property is
`quicktime:still-image-time`, emitted (including 0) for a single-sample
still-image-time track, absent otherwise, exactly the shape you described.
> Extract QuickTime timed metadata (mebx) tracks
> ----------------------------------------------
>
> Key: TIKA-4777
> URL: https://issues.apache.org/jira/browse/TIKA-4777
> Project: Tika
> Issue Type: Improvement
> Reporter: Dominik Schmidt
> Priority: Major
>
> Apple Live Photo videos mark the moment the paired still image was
> captured in a timed metadata track: the sample description declares the
> format 'mebx' with a keys structure containing
> com.apple.quicktime.still-image-time. The item value itself is always -1;
> the actual time is the presentation time of that sample, derived from the
> track's sample tables.
> Everything needed lives in the moov box, no mdat access is required:
> - mdhd: track timescale
> - stsd: detect the mebx sample entry and its still-image-time key
> - stts and elst: an empty edit shifts the single one-tick sample to the
> still moment
> Example from a real Live Photo video (iPhone 15 Pro, iOS 18.5): the
> still-image-time track has timescale 600, an edit list with an empty edit
> of 740 units followed by the sample, giving a still time of 1.2333 s.
> Neither the current MP4 handler (which reads the static keys/ilst
> metadata, TIKA-2861) nor the underlying metadata-extractor exposes timed
> metadata tracks; ExifTool only surfaces the constant -1 marker value.
> Note that the Apple maker note tag 0x0017 in the paired image
> (historically documented as "LivePhotoVideoIndex") does not encode a
> usable time on current iOS versions, so the video track is the only
> reliable source for this timestamp.
> Proposal: extend TikaMp4BoxHandler to accept the relevant trak child
> boxes, correlate mdhd/stsd/stts/elst per track, and emit the still time
> as metadata (e.g. com.apple.quicktime.still-image-time, in
> microseconds).
> Related: TIKA-2861 (QuickTime item-list metadata), TIKA-4776 (image-side
> Apple maker note, LONG8), TIKA-852.
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