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

[Måns Rullgård]

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.

-- 
M?ns Rullg?rd
mans at mansr.com