[FFmpeg-devel] [PATCH 4/5] avcodec/parser: Schedule av_parser_change for removal

[Anton Khirnov]

Quoting James Almer (2021-03-01 20:35:55)
> On 3/1/2021 12:36 PM, Andreas Rheinhardt wrote:
> > James Almer:
> >> On 2/26/2021 10:18 AM, Andreas Rheinhardt wrote:
> >>> Originally deprecated in 748c2fca7e4d99357c234936aa71212a6282be36,
> >>> publically deprecated in 9a07c1332cfe092b57b5758f22b686ca58806c60
> >>> (merged into FFmpeg in 1885ffb03d0af28e6bac2bcc8725fa15b93f6ac9).
> >>>
> >>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> >>> ---
> >>>    libavcodec/avcodec.h | 6 +++++-
> >>>    libavcodec/parser.c  | 3 ++-
> >>>    libavcodec/version.h | 3 +++
> >>>    3 files changed, 10 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> >>> index 3178c163b9..a8741df04b 100644
> >>> --- a/libavcodec/avcodec.h
> >>> +++ b/libavcodec/avcodec.h
> >>> @@ -3576,14 +3576,18 @@ int av_parser_parse2(AVCodecParserContext *s,
> >>>                         int64_t pts, int64_t dts,
> >>>                         int64_t pos);
> >>>    +#if FF_API_PARSER_CHANGE
> >>>    /**
> >>>     * @return 0 if the output buffer is a subset of the input, 1 if it
> >>> is allocated and must be freed
> >>> - * @deprecated use AVBitStreamFilter
> >>> + * @deprecated Use dump_extradata, remove_extra or extract_extradata
> >>> + *             bitstream filters instead.
> >>>     */
> >>> +attribute_deprecated
> >>>    int av_parser_change(AVCodecParserContext *s,
> >>>                         AVCodecContext *avctx,
> >>>                         uint8_t **poutbuf, int *poutbuf_size,
> >>>                         const uint8_t *buf, int buf_size, int keyframe);
> >>> +#endif
> >>>    void av_parser_close(AVCodecParserContext *s);
> >>>      /**
> >>> diff --git a/libavcodec/parser.c b/libavcodec/parser.c
> >>> index a63f532c48..f4bc00da7d 100644
> >>> --- a/libavcodec/parser.c
> >>> +++ b/libavcodec/parser.c
> >>> @@ -186,6 +186,7 @@ int av_parser_parse2(AVCodecParserContext *s,
> >>> AVCodecContext *avctx,
> >>>        return index;
> >>>    }
> >>>    +#if FF_API_PARSER_CHANGE
> >>>    int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
> >>>                         uint8_t **poutbuf, int *poutbuf_size,
> >>>                         const uint8_t *buf, int buf_size, int keyframe)
> >>> @@ -220,7 +221,7 @@ int av_parser_change(AVCodecParserContext *s,
> >>> AVCodecContext *avctx,
> >>>          return 0;
> >>>    }
> >>> -
> >>> +#endif
> >>>    void av_parser_close(AVCodecParserContext *s)
> >>>    {
> >>>        if (s) {
> >>> diff --git a/libavcodec/version.h b/libavcodec/version.h
> >>> index 488def4c23..815df15628 100644
> >>> --- a/libavcodec/version.h
> >>> +++ b/libavcodec/version.h
> >>> @@ -150,6 +150,9 @@
> >>>    #ifndef FF_API_MPV_RC_STRATEGY
> >>>    #define FF_API_MPV_RC_STRATEGY     (LIBAVCODEC_VERSION_MAJOR < 59)
> >>>    #endif
> >>> +#ifndef FF_API_PARSER_CHANGE
> >>> +#define FF_API_PARSER_CHANGE       (LIBAVCODEC_VERSION_MAJOR < 59)
> >>
> >> A doxygen deprecation notice is not enough to consider the function
> >> deprecated. There was no APIChanges entry and no attribute added to the
> >> function prototype.
> >> So this needs the APIChanges entry, and therefore be scheduled as < 60.
> > 
> > I disagree. Of course Doxygen deprecations count and being on the list
> > of deprecated things [1] for more than eight years is enough.
> 
> If there was no APIChanges entry that references a library version, then 
> this can not be considered deprecated

I do not agree that an APIChanges entry is necessary for a deprecation.
APIChanges is for listing API changes. A deprecation is not by itself an
API change, merely a statement of intent wrt future API changes.

>From the perspective of an API user it does not make much sense to ask
whether a feature X is deprecated in version Y, only whether a
replacement API is present. In this specific case, a replacement API has
been present since 2006 - for more than half the project's existence.
Surely that should be enough.

-- 
Anton Khirnov