Opened 2 years ago

Closed 2 years ago

#9648 closed defect (fixed)

IMF index seeking not supported

Reported by: jimz_01 Owned by: Pierre-Anthony Lemieux
Priority: normal Component: avformat
Version: git-master Keywords: IMF
Cc: jimz_01 Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: yes


Summary of the bug: the IMF ingest capability that was merged earlier this year does not appear to support index seeking. Seeking to a frame using "-s" and "-to" does produce the expected output video, but with large IMF assets, the operation takes a long time before the transcode begins (probably due to reading every frame)

How to reproduce (example command, should repro with any source):

ffmpeg -assetmaps LOKI-F004-VF-ERROR-FIX-V30149148-FP-DPO-IMFD-UHD-HDR-24-ENG-239-ENG/ASSETMAP.xml,LOKI-F004-OV-ERROR-V30149148-FP-DPO-IMFD-UHD-HDR-24-ENG-239-ENG/ASSETMAP.xml \
    -ss 585.0 -to 625.0 -pix_fmt yuv420p -vf scale=640:-2 -c:v libx264 -preset medium -crf 20 /tmp/proxy-VF.mp4

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

Change History (3)

comment:1 by Pierre-Anthony Lemieux, 2 years ago

Keywords: IMF added
Owner: set to Pierre-Anthony Lemieux
Reproduced by developer: set
Status: newopen

The IMF demuxer does not currently implement seeking.

Proposed patch at

comment:2 by Derek Prestegard, 2 years ago

This works great! I was able to render a segment of an IMP via -ss and -t with frame accuracy and good speed.

comment:3 by Pierre-Anthony Lemieux, 2 years ago

Analyzed by developer: set
Resolution: fixed
Status: openclosed
Note: See TracTickets for help on using tickets.