[FFmpeg-devel] [PATCH] lavf: deprecate AVFMT_FLAG_SHORTEST

[Andreas Rheinhardt]

Anton Khirnov:
> It was added in cb114ed4640 with the comment
> "This will allow fixing several bugs with the -shortest option".
> 
> Since
> * there is no explanation of what these bugs are
> * libavformat is not the place to work around ffmpeg CLI bugs
> * there is no indication that this feature is actually in use
> deprecate it without replacement.
> ---
>  doc/APIchanges              | 3 +++
>  libavformat/avformat.h      | 2 ++
>  libavformat/internal.h      | 2 ++
>  libavformat/mux.c           | 2 ++
>  libavformat/options.c       | 2 ++
>  libavformat/options_table.h | 4 +++-
>  libavformat/version_major.h | 1 +
>  7 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/doc/APIchanges b/doc/APIchanges
> index ad1efe708d..001de4544b 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
>  
>  API changes, most recent first:
>  
> +2023-08-xx - xxxxxxxxxx - lavf 60 - avformat.h
> +  Deprecate AVFMT_FLAG_SHORTEST without replacement.
> +
>  2023-08-18 - xxxxxxxxxx - lavu 58.17.100 - channel_layout.h
>    All AV_CHANNEL_LAYOUT_* macros are now compatible with C++ 17 and older.
>  
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> index 1916aa2dc5..8a145a8a8b 100644
> --- a/libavformat/avformat.h
> +++ b/libavformat/avformat.h
> @@ -1241,7 +1241,9 @@ typedef struct AVFormatContext {
>  #define AVFMT_FLAG_BITEXACT         0x0400
>  #define AVFMT_FLAG_SORT_DTS    0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
>  #define AVFMT_FLAG_FAST_SEEK   0x80000 ///< Enable fast, but inaccurate seeks for some formats
> +#if FF_API_LAVF_SHORTEST
>  #define AVFMT_FLAG_SHORTEST   0x100000 ///< Stop muxing when the shortest stream stops.
> +#endif
>  #define AVFMT_FLAG_AUTO_BSF   0x200000 ///< Add bitstream filters as requested by the muxer
>  
>      /**
> diff --git a/libavformat/internal.h b/libavformat/internal.h
> index 594afd731d..a016ef197d 100644
> --- a/libavformat/internal.h
> +++ b/libavformat/internal.h
> @@ -152,10 +152,12 @@ typedef struct FFFormatContext {
>  
>      int avoid_negative_ts_use_pts;
>  
> +#if FF_API_LAVF_SHORTEST
>      /**
>       * Timestamp of the end of the shortest stream.
>       */
>      int64_t shortest_end;
> +#endif
>  
>      /**
>       * Whether or not avformat_init_output has already been called
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 415bd3948f..b7ae90f3c4 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -990,6 +990,7 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
>          }
>      }
>  
> +#if FF_API_LAVF_SHORTEST
>      if (si->packet_buffer.head &&
>          eof &&
>          (s->flags & AVFMT_FLAG_SHORTEST) &&
> @@ -1025,6 +1026,7 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
>              flush = 0;
>          }
>      }
> +#endif
>  
>      if (stream_count && flush) {
>          PacketListEntry *pktl = si->packet_buffer.head;
> diff --git a/libavformat/options.c b/libavformat/options.c
> index e4a3aceed0..194042820e 100644
> --- a/libavformat/options.c
> +++ b/libavformat/options.c
> @@ -190,7 +190,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
>          return NULL;
>      }
>  
> +#if FF_API_LAVF_SHORTEST
>      si->shortest_end = AV_NOPTS_VALUE;
> +#endif
>  
>      return s;
>  }
> diff --git a/libavformat/options_table.h b/libavformat/options_table.h
> index 86d836cfeb..9aacd1ca2b 100644
> --- a/libavformat/options_table.h
> +++ b/libavformat/options_table.h
> @@ -51,7 +51,9 @@ static const AVOption avformat_options[] = {
>  {"fastseek", "fast but inaccurate seeks", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FAST_SEEK }, INT_MIN, INT_MAX, D, "fflags"},
>  {"nobuffer", "reduce the latency introduced by optional buffering", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_NOBUFFER }, 0, INT_MAX, D, "fflags"},
>  {"bitexact", "do not write random/volatile data", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_BITEXACT }, 0, 0, E, "fflags" },
> -{"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E, "fflags" },
> +#if FF_API_LAVF_SHORTEST
> +{"shortest", "stop muxing with the shortest stream (deprecated)", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E, "fflags" },
> +#endif
>  {"autobsf", "add needed bsfs automatically", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, "fflags" },
>  {"seek2any", "allow seeking to non-keyframes on demuxer level when supported", OFFSET(seek2any), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, D},
>  {"analyzeduration", "specify how many microseconds are analyzed to probe the input", OFFSET(max_analyze_duration), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},
> diff --git a/libavformat/version_major.h b/libavformat/version_major.h
> index 293fbd3397..e7e80184f7 100644
> --- a/libavformat/version_major.h
> +++ b/libavformat/version_major.h
> @@ -45,6 +45,7 @@
>  #define FF_API_GET_END_PTS              (LIBAVFORMAT_VERSION_MAJOR < 61)
>  #define FF_API_AVIODIRCONTEXT           (LIBAVFORMAT_VERSION_MAJOR < 61)
>  #define FF_API_AVFORMAT_IO_CLOSE        (LIBAVFORMAT_VERSION_MAJOR < 61)
> +#define FF_API_LAVF_SHORTEST            (LIBAVFORMAT_VERSION_MAJOR < 61)
>  
>  
>  #define FF_API_R_FRAME_RATE            1

LGTM (with the deprecated flag as noticed by James).

- Andreas