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big track does not play - lyapounov - 04-06-2020 16:47
I have an issue, and honestly it is hard for me to know where the problem is.
I have a very big single flac track, over one hour (64:46 minutes:seconds); 303Mo
Lumin app does see the file as 64:46 minutes, but on the top circle, it says 64:46 for half a second, then switch to 2:37, and the music stops at 2:37 (renderer is Klimax DS)
On another renderer (Yamaha WXAD-10), the top circle says 64:46 but again, the music stops at 2:37
I switched from lumin to Kazoo as a controller, well again the music stops at 2:37 and there is absolutely no indication of timing on this track.
I have looked at the file in audacity, and all is perfect, the 64 minutes are there.
What could it possibly be ?
Thx !
RE: big track does not play - lyapounov - 04-06-2020 17:15
OK: I have the same issue with other big files !
79:38 => 17:30
73:42 => 11:34
73:33 => 11:25
64:36 => 2:28
And here is the weird thing: for all those big files, the difference between the real timing and the timing the file is played is constant, and is 3728 seconds (62 minutes, 8 seconds)
I have actually 8 tracks which are above 3728 seconds (all my library is in synology mariadb, with lots of details ;-). And for all of them, the same phenomenon: the track is cut by 3728 seconds.
So the logic is: track is played it's timing modulo 3728 ;-)
Simon, looks like an overflow somewhere ???
RE: big track does not play - simoncn - 04-06-2020 21:53
Are you transcoding the FLAC file (for example, to WAV) when you play it? If so, what is the sample rate/bit depth of the original and transcoded versions?
RE: big track does not play - lyapounov - 05-06-2020 06:05
(04-06-2020 21:53)simoncn Wrote: Are you transcoding the FLAC file (for example, to WAV) when you play it? If so, what is the sample rate/bit depth of the original and transcoded versions?
yes: flac:wav24;192
all original tracks are 16/44
and I confirm that if I don't do any transcoding, the problem has disappeared, the file is played correctly and entirely
I use ffmpeg from http://johnvansickle.com/ffmpeg/
RE: big track does not play - simoncn - 05-06-2020 08:10
The WAV file format is limited to 4 GB maximum size. A 24/192 stereo file uses 1152000 bytes per second. The limit of 4 GB will be reached after 3728.27 seconds.
RE: big track does not play - lyapounov - 05-06-2020 08:37
(05-06-2020 08:10)simoncn Wrote: The WAV file format is limited to 4 GB maximum size. A 24/192 stereo file uses 1152000 bytes per second. The limit of 4 GB will be reached after 3728.27 seconds.
OK, that explains the 3728, but not why it takes the modulo. If it where a file, it would be cut at 3728 seconds; while here it takes only the remains of the division.
Anyway, I will downplay the frequency, which is not a big deal. Maybe that should deserve a warning somewhere on your web site ?
Thx Simon !
RE: big track does not play - simoncn - 05-06-2020 08:53
The modulo is explained because MinimServer's calculation of the file size uses a long integer which is automatically truncated to 32 bits when assigned to the stream length field. I think it would be a good idea to change this as you suggest and I will add this change to the next update. I will also add a comment to the Transcoding section to explain that WAV streams are limited to being less than 4GB.
RE: big track does not play - simoncn - 25-10-2020 19:55
I have done some more investigation of this issue. Because you are upsampling to 192 kHz, MinimStreamer uses FFmpeg to transcode FLAC to WAV and it is FFmpeg that is incorrectly setting the modulo length in the WAV header.
RE: big track does not play - lyapounov - 28-01-2021 17:15
(25-10-2020 19:55)simoncn Wrote: I have done some more investigation of this issue. Because you are upsampling to 192 kHz, MinimStreamer uses FFmpeg to transcode FLAC to WAV and it is FFmpeg that is incorrectly setting the modulo length in the WAV header.
Hi Simon
do you think FFmpeg developer can correct this ? And if so, what can I do ?
Cheers
Serge
RE: big track does not play - simoncn - 29-01-2021 12:22
There is a mechanism for submitting an FFmpeg bug report, described on this page. I think it would be better for me to submit the report as I can provide exact technical details of the issue. I will try to get to this soon.