Author Topic: iPod 5g / mini 2g: AAC playback problems (Read 2595 times)

michael.conner · « **on:** November 05, 2006, 12:43:36 PM »

iTunes 128 VBR and Nero AAC ~140kbps (can't remember the qval I chose when I originally encoded the tracks) of "normal" track length (~4 minutes) play back fine. However, I have a number of audiobooks encoded as single tracks with both iTunes (64k stereo) and Nero (q .30, "force LC profile" selected in dbPoweramp so they aren't encoded using SBR, came out between 100-128kbps) that range in size from 28MB-64MB. Rockbox chokes on them -- starts to load, but freezes and becomes unresponsive. I do hear the hard drive spinning if I put the iPod up to my ear. If I reboot and resume is turned on, it tries to load the same track and freezes again. (Clearing settings on reboot fixes the freeze cycle.)

EDIT: This occurs w/both CVS build 061104-1534 and daily build from 5 November for the 2g mini and with the 24 October daily build for the 5g iPod.

Lear · « **Reply #1 on:** November 06, 2006, 10:31:53 AM »

Hm... Sounds like it could be a problem decoding some metadata. Can you see how large the atoms in the moov atom is? One of the programs available here can show the information I'm looking for; I think it is mp4info, but it could also be mp4dump (can't easily test it at the moment).

Lear · « **Reply #2 on:** November 06, 2006, 02:28:11 PM »

mp4dump it is. But really long files can cause problems, yes. A table used for seeking and playback gets too large then. Should handle that case better, I think. And it might be possible to increase the max supported file size...

michael.conner · « **Reply #3 on:** November 06, 2006, 03:57:34 PM »

I'll check the files in question this evening and let you know what mp4dump says.

Lear · « **Reply #4 on:** November 06, 2006, 05:37:29 PM »

Apologies that I'm posting the whole thing, but other than the word "moov" I don't know what of this is useful and what isn't.

D:\>mp4dump "03 the ghosts of mendez.m4a"
mp4dump version 1.5.5
Dumping 03 the ghosts of mendez.m4a meta-information...
type ftyp
majorBrand = M4A
minorVersion = 0 (0x00000000)

type moov
type mvhd
version = 0 (0x00)
flags = 0 (0x000000)
creationTime = 3245246113 (0xc16e86a1)
modificationTime = 3245247731 (0xc16e8cf3)
timeScale = 44100 (0x0000ac44)
duration = 176173056 (0x0a803000)
rate = 1.000000
volume = 1.000000
reserved1 = <70 bytes>
00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00
00 00 00 00 00 00 00 00 00 00 40 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00
nextTrackId = 2 (0x00000002)
type trak
type tkhd
version = 0 (0x00)
flags = 7 (0x000007)
creationTime = 3245246113 (0xc16e86a1)
modificationTime = 3245247731 (0xc16e8cf3)
trackId = 1 (0x00000001)
reserved1 = <4 bytes> 00 00 00 00
duration = 176173056 (0x0a803000)
reserved2 = <12 bytes> 00 00 00 00 00 00 00 00 00 00 00 00
volume = 1.000000
reserved3 = <38 bytes>
00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00
00 00 40 00 00 00
width = 0.000000
height = 0.000000
type mdia
type mdhd
version = 0 (0x00)
flags = 0 (0x000000)
creationTime = 3245246113 (0xc16e86a1)
modificationTime = 3245247731 (0xc16e8cf3)
timeScale = 44100 (0x0000ac44)
duration = 176173056 (0x0a803000)
language = 21956 (0x55c4)
reserved = <2 bytes> 00 00
type hdlr
version = 0 (0x00)
flags = 0 (0x000000)
reserved1 = <4 bytes> 00 00 00 00
handlerType = soun
reserved2 = <12 bytes> 00 00 00 00 00 00 00 00 00 00 00 00
name =
type minf
type smhd
version = 0 (0x00)
flags = 0 (0x000000)
reserved = <4 bytes> 00 00 00 00
type dinf
type dref
version = 0 (0x00)
flags = 0 (0x000000)
entryCount = 1 (0x00000001)
type url
version = 0 (0x00)
flags = 1 (0x000001)
location = (null)
type stbl
type stsd
version = 0 (0x00)
flags = 0 (0x000000)
entryCount = 1 (0x00000001)
type mp4a
reserved1 = <6 bytes> 00 00 00 00 00 00
dataReferenceIndex = 1 (0x0001)
soundVersion = 0 (0x0000)
reserved2 = <6 bytes> 00 00 00 00 00 00
channels = 2 (0x0002)
sampleSize = 16 (0x0010)
packetSize = 0 (0x0000)
timeScale = 44100 (0x0000ac44)
reserved3 = <2 bytes> 00 00
type esds
version = 0 (0x00)
flags = 0 (0x000000)
ESID = 0 (0x0000)
streamDependenceFlag = 0 (0x0) <1 bits>
URLFlag = 0 (0x0) <1 bits>
OCRstreamFlag = 0 (0x0) <1 bits>
streamPriority = 0 (0x00) <5 bits>
decConfigDescr
objectTypeId = 64 (0x40)
streamType = 5 (0x05) <6 bits>
upStream = 0 (0x0) <1 bits>
reserved = 1 (0x1) <1 bits>
bufferSizeDB = 6144 (0x001800) <24 bits>
maxBitrate = 64000 (0x0000fa00)
avgBitrate = 64000 (0x0000fa00)
decSpecificInfo
info = <2 bytes> 12 10
profileLevelIndicationIndexDescr
slConfigDescr
predefined = 2 (0x02)
ipiPtr
ipIds
ipmpDescrPtr
langDescr
qosDescr
regDescr
extDescr
type stts
version = 0 (0x00)
flags = 0 (0x000000)
entryCount = 1 (0x00000001)

type stsc
version = 0 (0x00)
flags = 0 (0x000000)
entryCount = 2 (0x00000002)

type stsz
version = 0 (0x00)
flags = 0 (0x000000)
sampleSize = 0 (0x00000000)
sampleCount = 172044 (0x0002a00c)

type stco
version = 0 (0x00)
flags = 0 (0x000000)
entryCount = 8193 (0x00002001)

type udta
type meta
version = 0 (0x00)
flags = 0 (0x000000)
type hdlr
version = 0 (0x00)
flags = 0 (0x000000)
reserved1 = <4 bytes> 00 00 00 00
handlerType = mdir
reserved2 = <12 bytes> 61 70 70 6c 00 00 00 00 00 00 00 00
name =
type ilst
type âŒnam
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <23 bytes>
30 33 20 74 68 65 20 67 68 6f 73 74 73 20 6f 66
20 6d 65 6e 64 65 7a
type cpil
type data
version = 0 (0x00)
flags = 21 (0x000015)
reserved2 = <4 bytes> 00 00 00 00
metadata = <1 bytes> 00
type pgap
data = <17 bytes>
00 00 00 11 64 61 74 61 00 00 00 15 00 00 00 00
00
type tmpo
type data
version = 0 (0x00)
flags = 21 (0x000015)
reserved2 = <4 bytes> 00 00 00 00
metadata = <2 bytes> 00 00
type âŒtoo
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <32 bytes>
69 54 75 6e 65 73 20 76 37 2e 30 2e 31 2e 38 2c
20 51 75 69 63 6b 54 69 6d 65 20 37 2e 31 2e 33
type ----
type mean
version = 0 (0x00)
flags = 0 (0x000000)
metadata = <16 bytes> 63 6f 6d 2e 61 70 70 6c 65 2e 69 54 75 6e 65 73
type name
version = 0 (0x00)
flags = 0 (0x000000)
metadata = <8 bytes> 69 54 75 6e 53 4d 50 42
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <116 bytes>
20 30 30 30 30 30 30 30 30 20 30 30 30 30 30 38
34 45 20 30 30 30 30 30 30 30 45 20 30 30 30 30
30 30 30 30 30 41 38 30 32 37 41 34 20 30 30 30
30 30 30 30 30 20 30 30 30 30 30 30 30 30 20 30
30 30 30 30 30 30 30 20 30 30 30 30 30 30 30 30
20 30 30 30 30 30 30 30 30 20 30 30 30 30 30 30
30 30 20 30 30 30 30 30 30 30 30 20 30 30 30 30
30 30 30 30
type ----
type mean
version = 0 (0x00)
flags = 0 (0x000000)
metadata = <16 bytes> 63 6f 6d 2e 61 70 70 6c 65 2e 69 54 75 6e 65 73
type name
version = 0 (0x00)
flags = 0 (0x000000)
metadata = <8 bytes> 69 54 75 6e 4e 4f 52 4d
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <90 bytes>
20 30 30 30 30 30 31 46 42 20 30 30 30 30 30 31
46 33 20 30 30 30 30 39 31 30 44 20 30 30 30 30
37 32 43 37 20 30 30 32 35 41 36 31 34 20 30 30
32 35 41 36 31 34 20 30 30 30 30 34 43 43 34 20
30 30 30 30 34 42 46 33 20 30 30 30 33 34 35 32
41 20 30 30 32 43 38 31 45 35
type âŒART
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <19 bytes>
54 68 65 20 54 6f 6d 6f 72 72 6f 77 20 50 65 6f
70 6c 65
type âŒalb
type data
version = 0 (0x00)
flags = 1 (0x000001)
reserved2 = <4 bytes> 00 00 00 00
metadata = <20 bytes>
54 68 65 20 47 68 6f 73 74 73 20 6f 66 20 4d 65
6e 64 65 7a
type free
type free
type mdat

D:\>

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Lear

Developer
Member
Posts: 533

Re: iPod 5g / mini 2g: AAC playback problems

« Reply #5 on: November 07, 2006, 12:26:54 AM »

Well, I didn't say what I was interested in. But yes, this file is simply too long (the stsz atom, with the count 172044, is too large). I made some tests here, and it should be fairly easy to increased the limit, so that twice as long files can be handled.

Making it able to handle even longer files might be possible, but would require some investigations, as I don't know what, if anything, is possible yet. But I think it would be strange if it couldn't be improved somehow...

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michael.conner

Guest

Re: iPod 5g / mini 2g: AAC playback problems

« Reply #6 on: November 09, 2006, 04:56:27 PM »

Thanks -- the files work now with the newest CVS builds.

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