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

[Jason Garrett-Glaser]

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).

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