[FFmpeg-cvslog] r22288 - trunk/libavcodec/avcodec.h

[Alex Converse]

On Sun, Mar 7, 2010 at 4:37 PM, Reimar D?ffinger
<Reimar.Doeffinger at gmx.de> wrote:
> On Sun, Mar 07, 2010 at 10:16:44PM +0100, alexc wrote:
>> Author: alexc
>> Date: Sun Mar ?7 22:16:44 2010
>> New Revision: 22288
>>
>> Log:
>> Increase FF_INPUT_BUFFER_PADDING_SIZE to 64.
>>
>> The purpose of this is to give decoders a reasonable amount of buffer to work
>> with before needing to check for overreads.
>
> As you can't make use of this before the next major version bump anyway I'm
> not too sure if it's a good idea to increase it already now without an ifdef,
> it will hide issues from any fuzzer using FFmpeg while applications that were
> compiled or designed against and older version would remain to have the issues.

Yes applications that have issues that use libavcodec directly will
not be fixed until they recompile against libavcodec 52.56 or higher.
However applications that use libavcodec via libavformat or exec() the
ff* binaries will pick up the fix immediately.

Additionally, there is no sane way to stop these illegal reads without
increasing padding size.

I see this as a bit of an API addition. Everything that worked with
libavcodec 52.55 will still work with 52.56. Some stuff that didn't
work with 52.55, will work if recompiled against 52.56.