[x264-devel] X264 recovery_frame_cnt is out of spec

[Jason Garrett-Glaser]

On Thu, Sep 16, 2010 at 2:38 AM, Chris Brien <chris.brien at tandberg.com> wrote:
> On 15.09.2010 20:04, Jason Garrett-Glaser wrote:
>>
>> On Wed, Sep 15, 2010 at 8:16 AM, Chris
>> Brien<chris.brien at tandberg.com>  wrote:
>>>
>>> The H.264 spec section D.2.7 says "recovery_frame_cnt shall be in
>>> the range of 0 to MaxFrameNum-1, inclusive".
>>
>> That's rather lame.  Seems like we'll have to make MaxFrameNum larger
>> when intra refresh is on then.
>
> It is a bit lame. But then its meaning isn't "count this many frames until
> the picture is refreshed", but rather "this is what frame_num will be when
> the picture is refreshed",

Does that mean if the current frame num is 10, and it's 16 frames to
refresh, we need to set recovery_frame_cnt to 25?

> On the 21st frame, the whole picture has been refreshed, but on the 22nd
> frame, the final column of macroblocks is refreshed once more for good
> measure. X264 could skip doing this, and save bits.

This is a regression introduced in one of the earlier PIR patches (the
one to more accurately track PIR-related stuff).  Fixed locally.

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