Re: Coreaudio-api Digest, Vol 12, Issue 4
Re: Coreaudio-api Digest, Vol 12, Issue 4
- Subject: Re: Coreaudio-api Digest, Vol 12, Issue 4
- From: E Hartley <email@hidden>
- Date: Tue, 06 Jan 2015 22:02:48 +0000
My immediate suggestion is that the Lame encoding is at fault rather than the Apple decoder. There is an understanding in MPEG that decoder compliance is verified against reference bitstreams and that encoders must produce bit streams / files capable of being decoded by the reference software. No attempt is made to specify encoders. The fact that the fault is appearing at the end of the file makes me think that the encoder is not encoding the data or padding correctly for an audio file that is temporarily smaller than an integer number of encoding units. The way to verify this is either to dig into the MP3 file and inspect the structure or decode it against the reference software. Neither of these are entirely trivial.
HTH
Ed H
> On 6 Jan 2015, at 20:00, email@hidden wrote:
>
> Send Coreaudio-api mailing list submissions to
> email@hidden
>
> To subscribe or unsubscribe via the World Wide Web, visit
> https://lists.apple.com/mailman/listinfo/coreaudio-api
> or, via email, send a message with subject or body 'help' to
> email@hidden
>
> You can reach the person managing the list at
> email@hidden
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Coreaudio-api digest..."
>
>
> Today's Topics:
>
> 1. iOS AVAssetReader "This media may be damaged" issue (Kevin Dixon)
> 2. iOS AVAssetReader "This media may be damaged" issue (Kevin Dixon)
> 3. Re: iOS AVAssetReader "This media may be damaged" issue
> (Kevin Dixon)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 05 Jan 2015 14:50:30 -0800
> From: Kevin Dixon <email@hidden>
> To: coreaudio-api <email@hidden>
> Subject: iOS AVAssetReader "This media may be damaged" issue
> Message-ID:
> <email@hidden>
> Content-Type: text/plain; charset="utf-8"
>
> Hi All,
>
> I have an iOS app which was working great until the iOS 8 update, then
> users have started reporting that the playback of music from their iTunes
> library was glitching near the end of the song (last 8-15 seconds).
>
> The app uses AVAssetReader to read tracks from the MPMediaItem URL
> property, all very run of the mill sort of stuff.
>
> Now that I have reproduced the issue, we see the following info
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <https://lists.apple.com/mailman/private/coreaudio-api/attachments/20150105/6ef04854/attachment.html>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 05 Jan 2015 14:55:00 -0800
> From: Kevin Dixon <email@hidden>
> To: coreaudio-api <email@hidden>
> Subject: iOS AVAssetReader "This media may be damaged" issue
> Message-ID:
> <CANa-7D59WW05An=email@hidden>
> Content-Type: text/plain; charset="utf-8"
>
> (Sorry for the incomplete previous post, the email sent when I tried to
> paste)
>
> Hi All,
>
> I have an iOS app which was working great until the iOS 8 update, then
> users have started reporting that the playback of music from their iTunes
> library was glitching near the end of the song (last 8-15 seconds).
>
> The app uses AVAssetReader to read tracks from the MPMediaItem URL
> property, all very run of the mill sort of stuff.
>
> Now that I have reproduced the issue, we see the following info
>
> AVAssetReaderStatusFailed : Error Domain=AVFoundationErrorDomain
> Code=-11829 "Cannot Open" UserInfo=0x17d10cc0
> {NSLocalizedDescription=Cannot Open, NSUnderlyingError=0x17f192f0 "The
> operation couldn’t be completed. (OSStatus error -12848.)",
> NSLocalizedFailureReason=This media may be damaged.}
>
> The issue does not appear in the default iOS music app. For affected users,
> it only affects particular files. The nature of the file has not been
> clarified, some users thought it was Adobe Audition encoder which produced
> the bad files, some claimed VBR, but I can reproduced with a certain
> 160kbps CBR LAME-encoded file.
>
> I am curious if anyone else has seen this, or if maybe I should file a
> radar report?
>
> Thanks in advance.
>
> Kevin
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <https://lists.apple.com/mailman/private/coreaudio-api/attachments/20150105/ee197b0e/attachment.html>
>
> ------------------------------
>
> Message: 3
> Date: Mon, 05 Jan 2015 17:49:18 -0800
> From: Kevin Dixon <email@hidden>
> To: coreaudio-api <email@hidden>
> Subject: Re: iOS AVAssetReader "This media may be damaged" issue
> Message-ID:
> <CANa-7D7wmwBai6FtdDL1Nv3=4cCWGtLxrEXSSyns=email@hidden>
> Content-Type: text/plain; charset="utf-8"
>
> Filed Radar # 19381752
>
>> On Mon, Jan 5, 2015 at 2:55 PM, Kevin Dixon <email@hidden> wrote:
>>
>> (Sorry for the incomplete previous post, the email sent when I tried to
>> paste)
>>
>> Hi All,
>>
>> I have an iOS app which was working great until the iOS 8 update, then
>> users have started reporting that the playback of music from their iTunes
>> library was glitching near the end of the song (last 8-15 seconds).
>>
>> The app uses AVAssetReader to read tracks from the MPMediaItem URL
>> property, all very run of the mill sort of stuff.
>>
>> Now that I have reproduced the issue, we see the following info
>>
>> AVAssetReaderStatusFailed : Error Domain=AVFoundationErrorDomain
>> Code=-11829 "Cannot Open" UserInfo=0x17d10cc0
>> {NSLocalizedDescription=Cannot Open, NSUnderlyingError=0x17f192f0 "The
>> operation couldn’t be completed. (OSStatus error -12848.)",
>> NSLocalizedFailureReason=This media may be damaged.}
>>
>> The issue does not appear in the default iOS music app. For affected
>> users, it only affects particular files. The nature of the file has not
>> been clarified, some users thought it was Adobe Audition encoder which
>> produced the bad files, some claimed VBR, but I can reproduced with a
>> certain 160kbps CBR LAME-encoded file.
>>
>> I am curious if anyone else has seen this, or if maybe I should file a
>> radar report?
>>
>> Thanks in advance.
>>
>> Kevin
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <https://lists.apple.com/mailman/private/coreaudio-api/attachments/20150105/a9065ff2/attachment.html>
>
> ------------------------------
>
> _______________________________________________
> Coreaudio-api mailing list
> email@hidden
> https://lists.apple.com/mailman/listinfo/coreaudio-api
>
> End of Coreaudio-api Digest, Vol 12, Issue 4
> ********************************************
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden