[FFmpeg-devel] [PATCH 1/2] libavfilter: Support the forks ABI for buffer sinks

[Stefano Sabatini]

On date Friday 2012-08-31 22:38:29 +0200, Michael Niedermayer encoded:
> With this change avconv compiled against libav and linked to ffmpegs libs
> will run through the whole fate testsuite without any crashes.
> 857 tests pass, the remaining tests fail one way or another, which is
> to be expected as avconv is not a drop in replacement for ffmpeg
> The testsuite used was the ffmpeg fate testsuite, not libavs.
> 
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  libavfilter/allfilters.c  |    6 ++++++
>  libavfilter/buffersink.c  |    8 ++++++++
>  libavfilter/sink_buffer.c |   39 ++++++++++++++++++++++++++++++++++++---
>  3 files changed, 50 insertions(+), 3 deletions(-)
> 
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 9e68d4c..6842ec9 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -64,8 +64,11 @@ void avfilter_register_all(void)
>      REGISTER_FILTER (ANULLSRC,    anullsrc,    asrc);
>      REGISTER_FILTER (FLITE,       flite,       asrc);
>  

> +#if !AV_HAVE_INCOMPATIBLE_FORK_ABI
>      REGISTER_FILTER (ABUFFERSINK, abuffersink, asink);
> +#endif

After musing a few minutes I have to conclude that I'm lost at
correctly interpreting this:
INCOMPATIBLE (FORK ABI) => support the fork ABI, which is incompatible 
or
(INCOMPATIBLE FORK) ABI => support the ABI of the incompatible fork

>From my understanding abuffersink is compiled only if has not an
incompatible (i.e. has a compatible) fork ABI, otherwise only
ffabuffersink (ff* version) is compiled in.

If this interpretation is correct then I'd suggest:
INCOMPATIBLE_FORK_ABI => !LIBAV_ABI_COMPATIBILITY, and the previous
code becomes:

#if AV_HAVE_LIBAV_ABI_COMPATIBILITY
      REGISTER_FILTER (ABUFFERSINK, abuffersink, asink);
#endif

which seems easier to grasp to me.

>      REGISTER_FILTER (ANULLSINK,   anullsink,   asink);
> +    REGISTER_FILTER (FFABUFFERSINK, ffabuffersink, asink);
>  
>      REGISTER_FILTER (ALPHAEXTRACT, alphaextract, vf);
>      REGISTER_FILTER (ALPHAMERGE,  alphamerge,  vf);
> @@ -140,7 +143,10 @@ void avfilter_register_all(void)
>      REGISTER_FILTER (SMPTEBARS,   smptebars,   vsrc);
>      REGISTER_FILTER (TESTSRC,     testsrc,     vsrc);
>  
> +#if !AV_HAVE_INCOMPATIBLE_FORK_ABI
>      REGISTER_FILTER (BUFFERSINK,  buffersink,  vsink);
> +#endif
> +    REGISTER_FILTER (FFBUFFERSINK,ffbuffersink,vsink);
>      REGISTER_FILTER (NULLSINK,    nullsink,    vsink);
>  
>      /* multimedia filters */
> diff --git a/libavfilter/buffersink.c b/libavfilter/buffersink.c
> index e66a099..50cd6d4 100644
> --- a/libavfilter/buffersink.c
> +++ b/libavfilter/buffersink.c
> @@ -141,7 +141,11 @@ int av_buffersink_read_samples(AVFilterContext *ctx, AVFilterBufferRef **pbuf,
>  }
>  
>  AVFilter avfilter_vsink_buffer = {
> +#if AV_HAVE_INCOMPATIBLE_FORK_ABI
> +    .name      = "buffersink",
> +#else
>      .name      = "buffersink_old",
> +#endif
>      .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
>      .priv_size = sizeof(BufferSinkContext),
>      .uninit    = uninit,
> @@ -156,7 +160,11 @@ AVFilter avfilter_vsink_buffer = {
>  };
>  
>  AVFilter avfilter_asink_abuffer = {
> +#if AV_HAVE_INCOMPATIBLE_FORK_ABI
> +    .name      = "abuffersink",
> +#else
>      .name      = "abuffersink_old",
> +#endif
>      .description = NULL_IF_CONFIG_SMALL("Buffer audio frames, and make them available to the end of the filter graph."),
>      .priv_size = sizeof(BufferSinkContext),
>      .uninit    = uninit,
> diff --git a/libavfilter/sink_buffer.c b/libavfilter/sink_buffer.c
> index 95ba590..81bded0 100644
> --- a/libavfilter/sink_buffer.c
> +++ b/libavfilter/sink_buffer.c
> @@ -143,7 +143,7 @@ int av_buffersink_get_buffer_ref(AVFilterContext *ctx,
>      int ret;
>      *bufref = NULL;
>  
> -    av_assert0(!strcmp(ctx->filter->name, "buffersink") || !strcmp(ctx->filter->name, "abuffersink"));
> +    av_assert0(!strcmp(ctx->filter->name, "buffersink") || !strcmp(ctx->filter->name, "abuffersink") || !strcmp(ctx->filter->name, "ffbuffersink") || !strcmp(ctx->filter->name, "ffabuffersink"));

Nit: please split overly long line (and vertical align may help
readability), same below.

>  
>      /* no picref available, fetch it from the filterchain */
>      if (!av_fifo_size(buf->fifo)) {
> @@ -166,7 +166,7 @@ int av_buffersink_get_buffer_ref(AVFilterContext *ctx,
>  
>  AVRational av_buffersink_get_frame_rate(AVFilterContext *ctx)
>  {
> -    av_assert0(!strcmp(ctx->filter->name, "buffersink"));
> +    av_assert0(!strcmp(ctx->filter->name, "buffersink") || !strcmp(ctx->filter->name, "ffbuffersink"));
>  
>      return ctx->inputs[0]->frame_rate;
>  }
> @@ -176,7 +176,7 @@ int av_buffersink_poll_frame(AVFilterContext *ctx)
>      BufferSinkContext *buf = ctx->priv;
>      AVFilterLink *inlink = ctx->inputs[0];
>  
> -    av_assert0(!strcmp(ctx->filter->name, "buffersink") || !strcmp(ctx->filter->name, "abuffersink"));
> +    av_assert0(!strcmp(ctx->filter->name, "buffersink") || !strcmp(ctx->filter->name, "abuffersink") || !strcmp(ctx->filter->name, "ffbuffersink") || !strcmp(ctx->filter->name, "ffabuffersink"));
>      return av_fifo_size(buf->fifo)/sizeof(AVFilterBufferRef *) + ff_poll_frame(inlink);
>  }
-- 
FFmpeg = Foolish and Fast Mournful Pitiless Enhancing Gem