[FFmpeg-devel] [PATCH] Update lix264.c for x264 API change (X264_BUILD 79)

[Jason Garrett-Glaser]

On Mon, Nov 23, 2009 at 3:51 AM, Jason Garrett-Glaser
<darkshikari at gmail.com> wrote:
> 2009/11/23 M?ns Rullg?rd <mans at mansr.com>:
>> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
>>
>>> 2009/11/23 M?ns Rullg?rd <mans at mansr.com>:
>>>> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
>>>>
>>>>> On Sat, Nov 21, 2009 at 3:14 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>>>>>> On Sat, Nov 21, 2009 at 02:46:45PM -0800, Jason Garrett-Glaser wrote:
>>>>>>> On Sat, Nov 21, 2009 at 2:21 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>>>>>>> > On Sat, Nov 21, 2009 at 11:28:57AM -0800, Jason Garrett-Glaser wrote:
>>>>>>> >> OK, updated patch attached.
>>>>>>> > [...
>>>>>>> >> Index: libavcodec/avcodec.h
>>>>>>> >> ===================================================================
>>>>>>> >> --- libavcodec/avcodec.h ? ? ?(revision 20562)
>>>>>>> >> +++ libavcodec/avcodec.h ? ? ?(working copy)
>>>>>>> >> @@ -2553,6 +2553,13 @@
>>>>>>> >> ? ? ? * - decoding: Set by libavcodec, user can override.
>>>>>>> >> ? ? ? */
>>>>>>> >> ? ? ?int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
>>>>>>> >> +
>>>>>>> >> + ? ?/**
>>>>>>> >> + ? ? * explicit weighted prediction analysis method
>>>>>>> >> + ? ? * - encoding: Set by user.
>>>>>>> >> + ? ? * - decoding: unused
>>>>>>> >> + ? ? */
>>>>>>> >> + ? ?int weighted_p_pred;
>>>>>>> >> ?} AVCodecContext;
>>>>>>> >
>>>>>>> > This documentation is insufficient to use this field.
>>>>>>> > It tells the reader what the field does but not which value does
>>>>>>> > what
>>>>>>>
>>>>>>> How should we keep the documentation in ffmpeg synced with the values
>>>>>>> in x264 then? ?We may add new values in the future.
>>>>>>
>>>>>> Theres no problem with adding new values in avcodec.h, removing or changing
>>>>>> them is a problem, but i would suspect that is not planned.
>>>>>>
>>>>>> The idea simply is that an application that uses libavcodec (and x264 throgh
>>>>>> libavcodec) keeps working with new libavcodec or x264 versions unless the
>>>>>> major version is bumped.
>>>>>> Adding values (which the old application doesnt know about) is no problem
>>>>>> redefining their meaning would be one though possibly not a huge one
>>>>>
>>>>> Updated.
>>>>>
>>>>> +{"wpredp", "weighted prediction analysis method", OFFSET(weighted_p_pred), FF_OPT_TYPE_INT, 0, INT_MIN, INT_MAX, V|E},
>>>>
>>>> What is "wpredp" supposed to be short for?
>>>>
>>>>> Index: libavcodec/avcodec.h
>>>>> ===================================================================
>>>>> --- libavcodec/avcodec.h ? ? ?(revision 20562)
>>>>> +++ libavcodec/avcodec.h ? ? ?(working copy)
>>>>> @@ -2553,6 +2553,16 @@
>>>>> ? ? ? * - decoding: Set by libavcodec, user can override.
>>>>> ? ? ? */
>>>>> ? ? ?int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
>>>>> +
>>>>> + ? ?/**
>>>>> + ? ? * explicit weighted prediction analysis method
>>>>> + ? ? * 0: off
>>>>> + ? ? * 1: fast blind weighting (one reference duplicate with -1 offset)
>>>>> + ? ? * 2: smart weighting (full fade detection analysis)
>>>>> + ? ? * - encoding: Set by user.
>>>>> + ? ? * - decoding: unused
>>>>> + ? ? */
>>>>> + ? ?int weighted_p_pred;
>>>>> ?} AVCodecContext;
>>>>
>>>> The weighted_p_pred name looks a bit weird to me. ?What does the _p_ signify?
>>>
>>> P-frames, in the same way that weightb means weighted B-frames. ?Most
>>> importantly it fits with the x264 name (weightp).
>>
>> So this is only for P-frames? ?That's not at all obvious.
>
> Well, in the future, x264 could theoretically get explicit weighted
> prediction support for B-frames as well, though I haven't seen that
> used very commonly, and I would still personally call it weightp
> (since its primary purpose is to weight P-frames, which don't get hit
> by implicit weighted pred, aka weightb).
>
> I've renamed it to "explicit P-frame weighted prediction analysis
> method" accordingly.
>
> Dark Shikari
>
Bump?  I'd like to get this in soon.


Dark Shikari