On 21/10/2019 09:28, Moritz Barsnick wrote: > Hi Budgie, > > On Sun, Oct 20, 2019 at 09:56:40 +0100, Budge wrote: >> I have a set of m4a audio files which I can play but on which the >> progress bar does not work. If I select anywhere along the progress bar >> playing starts again from the beginning. > > In which players does seeking not work? In all of them? Which did you > test? > > How were there files created? Are they arbitrary files, or did you > create them with ffmpeg? > > Can you provide some of these files? > >> The only difference I can see when using ffprobe to examine the metadata >> is that files which have a creation_time set have a non functioning >> progress bar problem. > > That may be a symptom of their creation, but not the actual root cause > for your issues. > >> What I wish to do is remove the tag: >> creation_time : 1970-01-01T00:00:00.000000Z > > ffmpeg certainly didn't create this by itself, but I understand that's > not what you're trying to say. ;-) > >> I confess using ffmpeg to achieve this, if indeed this is the correct >> tool, is well beyond my ability and I am seeking help here. > > Even though I don't believe that is the root cause, I was going to explain > to you how to strip metadata using ffmpeg. But it turns out that, when > remuxing, ffmpeg doesn't actually copy the creation_time. So all you > have to do may be: > > $ ffmpeg -i input.m4a -c copy output.m4a > > You can then test the output file. > > The resulting file may also be fixed for other reasons than the > metadata, e.g. reconstruction of some index or something like that, > which the original may be missing. (Guessing here - just go try.) > > Hope this helps, > Moritz > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". > Hi and very many thanks for the detailed reply.
I obtained the file from BBC using get_iplayer, one of several and years ago. I believe the problem resulted from my poor workmanship when, while upgrading my workstation, I failed to install AtomicParsley. (Running on 64 bit system with openSUSE but cannot recall version.) As a result the files would not play on the Linn DS until I moved the moov atom to the start of the file metadata using qt-faststart but otherwise I believe the tags were intact. The files then played OK but the progress bar problem was present. I can let you have samples of good and bad files for comparison but they are quite big so need your advice how to get them to you. I can use Dropbox and send a link if this would be OK. The problem only occurs with my Linn DS devices. I am using BubbleDS on Samsung S6 Android phone as control point and minimserver on Qnap NAS as media server. On another player such as a RaspberryPi with Raspbian OS and IQaudio PiDAC etc and Upmpdcli the progress bar works as it should. AFAIK get_iplayer uses ffmpeg when downloading but I am not a coder so cannot comment further. In the light of your advice above there may be other criteria to examine in the file as; None of the files I have which do NOT have the creation_time tag work perfectly. Only those files which still have the creation_time tag have a problem with the Linn DS devices. Meanwhile I will try your suggestion and report progress. Many thanks once more. Regards, Budge _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
