[x264-devel] Fwd: Attention: Bug ID 8296253: Live HTTP stream causes iPad to reboot after some time

aviad rozenhek aviadr1 at gmail.com
Thu Sep 2 18:53:29 CEST 2010

Dear Experts,

I used x264 r1629 to encode video for ipad. when played in quicktime, it
occasionally reboots (goes into "panic mode" in apple terms).
apple has identified the bug on their side as something to do with the
idr_pic_id being very large.
is there some way to tweak x264 settings so as to workaround the bug in

original message from apple below:

Begin forwarded message:

*From: *Apple Developer Bug Reporting <devbugs at apple.com>
*Date: *August 26, 2010 7:55:39 PM GMT+03:00
*Subject: **Attention: Bug ID 8296253: Live HTTP stream causes iPad to
reboot after some time*

This is a courtesy email regarding Bug ID# 8296253.

Engineering has provided the following feedback regarding this issue:

This issue will be addressed in an upcoming release. Until then here's a
possible workaround:

The idr_pic_id in the slice header for IDR frame is very large and is
encoded using lots of  bits (which of course is legal).  We would suggest
making idr_pic_id as small as possible so that it is encoded using fewer in
the slice header .

Bug reports requiring your attention will appear under ‘My Originated
Problems’.  Please review this bug report and provide the requested
information via the Apple Bug Reporter. Once your report has been updated,
engineering will be alerted of the new information.


Thank you for your assistance in helping us discover and isolate bugs within
our products.

Best Regards,

Apple Developer Connection
Worldwide Developer Relations
Bug ID #: 8296253
Bug Title: Live HTTP stream causes iPad to reboot after some time
<GMT11-Aug-2010 09:37:24GMT> Ofer Shem-Tov:
'iPad_ts.zip' was successfully uploaded

<GMT11-Aug-2010 09:37:24GMT> Ofer Shem-Tov:
Summary: Our encoder produce a stream using H.264 main profile level 3.1 in
our proprietary protocol. This stream converted to Live HTTP Streaming
format causes the iPad to reboot after some time (seconds or minutes). Those
streams will play without a problem on iPhone 3GS with iOS 4.1 beta 3 or iOS
3.1.2. Streams with baseline profile from our encoder play without problems
on iPhone and iPad. The encoder is X.264 based.

Steps to Reproduce:

This stream is generated by our encoder and packaged as Live HTTP Stream by
Wowza media server. After sometime of playing this stream the iPad reboots:

This attached stream fragment iPad_ts.zip (includes playlist file and
several ts files in a zip archive) is generated by our code on the iPad
itself by converting from our protocol to Live HTTP Stream. It is a fragment
from a stream that will reboot the iPad if it continues but itself does not
cause reboot.

Expected Results:

The stream should play on the iPad or stop with error.

Actual Results:

The stream plays ok for some time (seconds or minutes) and then the iPad



The problem might be caused by packet loss and thats why its not always
reboots on the same location.
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