[FFmpeg-devel] [PATCH v4 08/13] avutil/frame: add helper for extending a set of side data

[James Almer]

On 9/1/2023 5:38 PM, Jan Ekström wrote:
> Additionally, extend the side data set FATE test to check for the
> invalid use case of extending a set by itself.
> ---
>   libavutil/frame.c               | 32 ++++++++++++++++++++++++++++++++
>   libavutil/frame.h               | 15 +++++++++++++++
>   libavutil/tests/side_data_set.c | 16 ++++++++++++++++
>   tests/ref/fate/side_data_set    |  7 +++++++
>   4 files changed, 70 insertions(+)
> 
> diff --git a/libavutil/frame.c b/libavutil/frame.c
> index 5f74e0172b..898c749631 100644
> --- a/libavutil/frame.c
> +++ b/libavutil/frame.c
> @@ -879,6 +879,38 @@ AVFrameSideData *av_frame_side_data_set_new_item(AVFrameSideDataSet *set,
>       return ret;
>   }
>   
> +int av_frame_side_data_set_extend(AVFrameSideDataSet *dst,
> +                                  const AVFrameSideDataSet src,
> +                                  unsigned int flags)

I think a standard, more versatile add() function would be better. The 
signature would be something like

av_frame_side_data_set_add_item(AVFrameSideDataSet *set,
                                 const AVBufferRef *buf,
                                 unsigned int flags);

It would also be a good chance to fix the non standard behavior i had 
misfortune to introduce with av_frame_new_side_data_from_buf() by having 
this function actually create a new reference to the passed in buffer 
rather than take ownership of it.

> +{
> +    if (src.nb_sd > 0 && src.nb_sd == dst->nb_sd &&
> +        src.sd == dst->sd)
> +        return AVERROR(EINVAL);
> +
> +    for (int i = 0; i < src.nb_sd; i++) {
> +        const AVFrameSideData *sd_src = src.sd[i];
> +        AVBufferRef           *buf    = av_buffer_ref(sd_src->buf);
> +        AVFrameSideData       *sd_dst =
> +            add_side_data_to_set_from_buf(dst, sd_src->type, buf);
> +        if (!sd_dst) {
> +            av_buffer_unref(&buf);
> +            av_frame_side_data_set_uninit(dst);
> +            return AVERROR(ENOMEM);
> +        }
> +
> +        {
> +            int ret = av_dict_copy(&sd_dst->metadata, sd_src->metadata, 0);
> +            if (ret < 0) {
> +                av_frame_side_data_set_uninit(dst);
> +                return ret;
> +            }
> +        }
> +
> +    }
> +
> +    return 0;
> +}
> +
>   AVFrameSideData *av_frame_side_data_set_get_item(const AVFrameSideDataSet set,
>                                                    enum AVFrameSideDataType type)
>   {
> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index 8ecdf82f33..e16941c5a5 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -1085,6 +1085,21 @@ AVFrameSideData *av_frame_side_data_set_new_item(AVFrameSideDataSet *set,
>                                                    size_t size,
>                                                    unsigned int flags);
>   
> +/**
> + * Add multiple side data entries to a set in one go.
> + *
> + * @param dst a set to which the side data should be added
> + * @param src a set from which the side data should be copied from
> + * @param flags Some combination of AV_FRAME_SIDE_DATA_SET_FLAG_* flags, or 0.
> + *
> + * @return negative error code on failure, >=0 on success.
> + *
> + * @see av_frame_side_data_set_new_item regarding the flags.
> + */
> +int av_frame_side_data_set_extend(AVFrameSideDataSet *dst,
> +                                  const AVFrameSideDataSet src,
> +                                  unsigned int flags);
> +
>   /**
>    * Get a side data entry of a specific type from a set.
>    *
> diff --git a/libavutil/tests/side_data_set.c b/libavutil/tests/side_data_set.c
> index 056d79f655..0c9ceed962 100644
> --- a/libavutil/tests/side_data_set.c
> +++ b/libavutil/tests/side_data_set.c
> @@ -91,6 +91,22 @@ int main(void)
>       puts("\nFinal state after a single 'no-duplicates' addition:");
>       print_clls(set);
>   
> +    {
> +        AVFrameSideDataSet dst_set = { 0 };
> +        av_assert0(av_frame_side_data_set_extend(&dst_set, set, 0) >= 0);
> +
> +        puts("\nState of the copied set:");
> +        print_clls(dst_set);
> +
> +        av_frame_side_data_set_uninit(&dst_set);
> +    }
> +
> +    {
> +        int ret = av_frame_side_data_set_extend(&set, set, 0);
> +        printf("\nResult of trying to extend a set by itself: %s\n",
> +               av_err2str(ret));
> +    }
> +
>       av_frame_side_data_set_uninit(&set);
>   
>       return 0;
> diff --git a/tests/ref/fate/side_data_set b/tests/ref/fate/side_data_set
> index 7d8c684d8f..3050b31014 100644
> --- a/tests/ref/fate/side_data_set
> +++ b/tests/ref/fate/side_data_set
> @@ -12,3 +12,10 @@ Final state after a single 'no-duplicates' addition:
>   sd 0, Ambient viewing environment
>   sd 1, Spherical Mapping
>   sd 2, Content light level metadata: MaxCLL: 1337
> +
> +State of the copied set:
> +sd 0, Ambient viewing environment
> +sd 1, Spherical Mapping
> +sd 2, Content light level metadata: MaxCLL: 1337
> +
> +Result of trying to extend a set by itself: Invalid argument