On 13/01/17 00:24, RS wrote:
From: Budge Sent: Thursday, January 12, 2017 18:26
Many thanks. Yes I agree ffmpeg was my first thought but I am spoiled
for choice of command options. ffprobe output didn't tell me what I
was looking for although that may be due to me not understanding what
I was looking at. However I have no doubt ffmpeg will clean things
up. I shall try a few options and see what happens.
Thanks for drawing attention to this. I did hope something similar
might lead to a solution of the problem I have playing DASH/M4A/AAC
files on my AGPtEK A02. I found about a year ago that ffmpeg created
files with Major Brand M4A and Minor Version 512, which the AGPtEK
player did not seem to like. I used
mp4box <file>.m4a -brand M4A:0 -out <file1>.m4a
from https://gpac.wp.mines-telecom.fr/mp4box/mp4box-documentation/
to change the Minor Version to 0. I then found I could play the files,
but only if they were shorter than 14min at 128kbit/s.
Following your post I have looked at it again. I see that by default
mp4box -brand M4A introduces interleaving of 500ms. I tried
mp4box <file>.m4a -brand M4A:0 -inter 1000 -out <file1>.m4a
to give 1s interleaving and that allowed a 24min file to be played, but
the display showed Format error after 15min. I also tried -inter 2000
for 2s interleaving. That again allowed a 24min file to be played but
with a Format error after 5min.
mp4box <file> -info
gives a bit more information than ffprobe and ffmpeg. GPAC refers to
segments, fragments and interleaving. I am not sure how these relate to
what Linn calls chunks.
I have tried running ffmpeg with -acodec copy and with -acodec aac, but
that does not seem to help.
artisticforge said Handbrake fixed his files. Handbrake will not
convert audio only files. I have seen a workaraound to add dummy video,
but that seemed a bit cumbersome. I'll have to give it a try.
Interesting. I thought I would have a look at mp4box but cannot find it
although I have gpac installed. I could download and build but wonder
why it is not shown in Packman repo along with gpac. Will dig further.
Meanwhile I am learning (slowly) a whole lot more about this through
necessity. I should point out however that my files are from 2 hours
and up to more than twice as long. Strange that only the Linn kit
chokes on these but they are now aware of the issue.
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