Opened 7 years ago

Closed 7 years ago

#2740 closed defect (invalid)

Concatenating m4a files FAILED with output file name 'con.m4a'

Reported by: yumeyao Owned by: yumeyao
Priority: normal Component: undetermined
Version: unspecified Keywords:
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


Summary of the bug:
It seems the name 'con.m4a' is internally used or somewhat, I saw this message:

Input #0, concat, from 'mylist.txt':
  Duration: 00:00:00.00, start: 0.000000, bitrate: 163 kb/s
    Stream #0:0: Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 162 kb/s
File 'con.m4a' already exists. Overwrite ? [y/N]

Of course there's no such file there.

If I choose Yes:

[ipod @ 0261d2c0] muxer does not support non seekable output
Output #0, ipod, to 'con.m4a':
    encoder         : Lavf55.10.100
    Stream #0:0: Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, 162 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Could not write header for output file #0 (incorrect codec parameters ?): Error number -1 occurred

And yes, just by changing the output file name, the whole process goes to work.

How to reproduce:

% ffmpeg -f concat -i mylist.txt -c copy con.m4a
ffmpeg version N-54277-gff130d7 Copyright (c) 2000-2013 the FFmpeg developers
  built on Jun 30 2013 01:20:12 with gcc 4.7.3 (GCC)

(This is the version from, I was just lazy to build it myself because I just wanted to try out the concat function instructed in the wiki:,%20merge)%20media%20files

mylist.txt content:


Change History (4)

comment:1 Changed 7 years ago by cehoyos

Please provide your failing command line together with the complete, uncut console output to make this a valid ticket.

comment:2 Changed 7 years ago by DJX

If this is on Windows, this is not a bug.
There are reserved resource names in Windows that can not be used for files or folders, no matter what the extension.

"con" & "prn" are two I can think of off the top of my head.
They stand for console and printer.

comment:3 Changed 7 years ago by yumeyao

  • Owner set to yumeyao
  • Status changed from new to open

you're correct. This is not a ffmepg issue. Sorry for mis-reporting.
I'll close it.

--- EDIT ---
It seems I can't close even the owner is set to me. I guess only a developer could close it?

Last edited 7 years ago by yumeyao (previous) (diff)

comment:4 Changed 7 years ago by cehoyos

  • Priority changed from minor to normal
  • Resolution set to invalid
  • Status changed from open to closed
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