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Corrupted Downloads?
24-12-2012, 00:55
Post: #1
Corrupted Downloads?
Some of my BBC downloads cause a crash when trying to play using BubbleDS and Minimserver. The Minimserver log has messages such as:-

Warning: unexpected image item class 0 at offset 409799773 in file Music/Radio_Programme/BBC_Proms/BBC_Proms_-_2012_Season_Prom_28_1._Chabrier_Mozart_Elaine_Agnew_b01lhhzk_default.m4a (length 409799777).

I know it is not a minimserver problem but is there any way I can remove the offending image please?
Budgie
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24-12-2012, 08:44
Post: #2
RE: Corrupted Downloads?
(24-12-2012 00:55)Budgie Wrote:  Some of my BBC downloads cause a crash when trying to play using BubbleDS and Minimserver. The Minimserver log has messages such as:-

Warning: unexpected image item class 0 at offset 409799773 in file Music/Radio_Programme/BBC_Proms/BBC_Proms_-_2012_Season_Prom_28_1._Chabrier_Mozart_Elaine_Agnew_b01lhhzk_default.m4a (length 409799777).

I know it is not a minimserver problem but is there any way I can remove the offending image please?
Budgie

I suspect this file is not in m4a format. Please run the following command and post the results here.

hexdump -C -n 512 <filename>
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29-12-2012, 16:30
Post: #3
RE: Corrupted Downloads?
(24-12-2012 08:44)simoncn Wrote:  
(24-12-2012 00:55)Budgie Wrote:  Some of my BBC downloads cause a crash when trying to play using BubbleDS and Minimserver. The Minimserver log has messages such as:-

Warning: unexpected image item class 0 at offset 409799773 in file Music/Radio_Programme/BBC_Proms/BBC_Proms_-_2012_Season_Prom_28_1._Chabrier_Mozart_Elaine_Agnew_b01lhhzk_default.m4a (length 409799777).

I know it is not a minimserver problem but is there any way I can remove the offending image please?
Budgie

I suspect this file is not in m4a format. Please run the following command and post the results here.

hexdump -C -n 512 <filename>
Code:
00000000  00 00 00 18 66 74 79 70  4d 34 41 20 00 00 02 00  |....ftypM4A ....|
00000010  69 73 6f 6d 69 73 6f 32  00 00 00 08 66 72 65 65  |isomiso2....free|
00000020  18 52 38 0c 6d 64 61 74  21 1c 53 9d ba 8c 89 12  |.R8.mdat!.S.....|
00000030  80 c4 20 4a 38 5f 05 26  de 81 bc 4a 2e 80 74 26  |.. J8_.&...J..t&|
00000040  17 2a 4a 5d 01 10 01 13  f2 d7 97 c9 f9 03 aa 90  |.*J]............|
00000050  37 4e 21 e0 8e ec 43 a7  74 a2 1d c7 c2 a4 3c 15  |7N!...C.t.....<.|
00000060  cf 48 cf de 93 ec 9d 4c  9f 16 cc 93 d6 f0 42 7c  |.H.....L......B||
00000070  ab a2 13 e9 9d 1c 9f 36  e3 44 f7 19 4b 1a 71 09  |.......6.D..K.q.|
00000080  f8 62 19 4c d9 0d 06 9c  86 c7 74 43 88 f0 f2 1c  |.b.L......tC....|
00000090  13 62 43 33 7a 81 82 4c  f1 09 ce ac 4e dd f2 78  |.bC3z..L....N..x|
000000a0  2c 29 2c 3e 2c 9c 45 64  22 5a 29 c9 26 30 3b 31  |,),>,.Ed"Z).&0;1|
000000b0  16 08 c3 04 22 1d 7f 8f  f1 ba d8 4c 1a 34 69 c0  |...."......L.4i.|
000000c0  75 8b 6f 7f a8 55 1e fc  1d cd e1 60 62 1d f8 03  |u.o..U.....`b...|
000000d0  05 a8 87 87 9f f9 87 fc  04 6f 6f cf f6 e2 3c fb  |.........oo...<.|
000000e0  fb 8f 04 7f cf a4 a1 f6  8b 52 18 0f 77 1f f8 0f  |.........R..w...|
000000f0  9b 84 41 5e 5d 67 d3 f2  cd 82 3f b7 ee 02 7a 7b  |..A^]g....?...z{|
00000100  df fa 9f d8 1a 21 98 f9  0d b0 25 10 bd 21 2d 1b  |.....!....%..!-.|
00000110  60 cc 5c 20 e1 f2 89 e0  30 b2 62 2c 0a 08 38 79  |`.\ ....0.b,..8y|
00000120  3c 5d 8d 59 b3 66 dd 48  4e 4e 4e 46 18 04 73 72  |<].Y.f.HNNNF..sr|
00000130  79 de 56 fe 19 e2 48 62  2c 13 8a 00 44 76 72 73  |y.V...Hb,...Dvrs|
00000140  f3 ed cd 9b 0a 43 38 ca  2c 11 84 0e dd bb 79 3c  |.....C8.,.....y<|
00000150  5e 2d fc 26 96 4c 46 d1  b4 58 16 27 93 c5 e2 f1  |^-.&.LF..X.'....|
00000160  76 36 e5 a0 62 42 72 72  71 a1 03 b3 9f 9f 8f 6e  |v6..bBrrq......n|
00000170  ac b4 0c 34 9c 9c 8c 50  00 6c db cf cf c7 ab 2c  |...4...P.l.....,|
00000180  06 12 13 93 91 8a 08 1d  9c 9c fc fb 75 61 80 c2  |............ua..|
00000190  42 72 72 31 40 01 b3 6f  3f 3e dd 58 74 01 f9 2e  |Brr1@..o?>.Xt...|
000001a0  54 94 ba 02 20 02 df fe  00 00 00 00 00 00 00 00  |T... ...........|
000001b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00000200
Hi Simon,
Hope the above makes sense.
Regards,
Budgie
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29-12-2012, 17:59
Post: #4
RE: Corrupted Downloads?
(29-12-2012 16:30)Budgie Wrote:  Hi Simon,
Hope the above makes sense.
Regards,
Budgie

Yes, it does. The contents of this file are in an unusual order, so I'll need to see the end portion of this file as well. Please run the command

tail -c 2000000 Music/Radio_Programme/BBC_Proms/BBC_Proms_-_2012_Season_Prom_28_1._Chabrier_Mozart_Elaine_Agnew_b01lhhzk_default.m4a >endportion

This should produce a file named endportion with length 2000000 bytes. Please upload this endportion file to my FTP site. Thanks!
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30-12-2012, 00:04
Post: #5
RE: Corrupted Downloads?
(29-12-2012 17:59)simoncn Wrote:  
(29-12-2012 16:30)Budgie Wrote:  Hi Simon,
Hope the above makes sense.
Regards,
Budgie
Yes, it does. The contents of this file are in an unusual order, so I'll need to see the end portion of this file as well. Please run the command

tail -c 2000000 Music/Radio_Programme/BBC_Proms/BBC_Proms_-_2012_Season_Prom_28_1._Chabrier_Mozart_Elaine_Agnew_b01lhhzk_default.m4a >endportion

This should produce a file named endportion with length 2000000 bytes. Please upload this endportion file to my FTP site. Thanks!
Hi Simon,
File with you now.
Regards,
Budgie
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30-12-2012, 09:54
Post: #6
RE: Corrupted Downloads?
(30-12-2012 00:04)Budgie Wrote:  Hi Simon,
File with you now.
Regards,
Budgie

Thanks for doing this. The last item in this file is a 'covr' atom without any image content, and MinimServer doesn't handle this case correctly. I'm not sure whether it's legal to have a 'covr' atom without any image content, but it's a simple change for MinimServer to detect this and ignore the empty 'covr' atom.

I'll put a fix into the next release of MinimServer. Meanwhile, you could modify the file by using a hex editor to replace the characters 'covr' by some other characters such as 'xxxx'. In the file you sent me, these 'covr' characters are 16 bytes before the end of the file. Don't change anything else in the file.
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31-12-2012, 18:43
Post: #7
RE: Corrupted Downloads?
(30-12-2012 09:54)simoncn Wrote:  
(30-12-2012 00:04)Budgie Wrote:  Hi Simon,
File with you now.
Regards,
Budgie

Thanks for doing this. The last item in this file is a 'covr' atom without any image content, and MinimServer doesn't handle this case correctly. I'm not sure whether it's legal to have a 'covr' atom without any image content, but it's a simple change for MinimServer to detect this and ignore the empty 'covr' atom.

I'll put a fix into the next release of MinimServer. Meanwhile, you could modify the file by using a hex editor to replace the characters 'covr' by some other characters such as 'xxxx'. In the file you sent me, these 'covr' characters are 16 bytes before the end of the file. Don't change anything else in the file.
Hi Simon,
Many thanks for the suggested fix. The question arises where and why does this problem manifest itself because I have quite a few files. Will meanwhile try and fix as you suggest. Interesting concept; an empty atom!
Regards,
Budgie
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31-12-2012, 19:00
Post: #8
RE: Corrupted Downloads?
(31-12-2012 18:43)Budgie Wrote:  Hi Simon,
Many thanks for the suggested fix. The question arises where and why does this problem manifest itself because I have quite a few files. Will meanwhile try and fix as you suggest. Interesting concept; an empty atom!
Regards,
Budgie

If you get a message from MinimServer about an unexpected image item class 0, it's likely to be caused by this issue. This message includes the filename and offset of the offending atom.
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