[FFmpeg-devel] [PATCH v8 06/14] avutil/frame: add helper for adding existing side data to array

[James Almer]

On 3/11/2024 5:58 PM, Jan Ekström wrote:
> ---
>   libavutil/frame.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++
>   libavutil/frame.h | 20 +++++++++++++++++++
>   2 files changed, 69 insertions(+)
> 
> diff --git a/libavutil/frame.c b/libavutil/frame.c
> index 4074391a92..46f976a3ed 100644
> --- a/libavutil/frame.c
> +++ b/libavutil/frame.c
> @@ -98,6 +98,23 @@ static void remove_side_data(AVFrameSideData ***sd, int *nb_side_data,
>       }
>   }
>   
> +static void remove_side_data_by_entry(AVFrameSideData ***sd, int *nb_sd,
> +                                      const AVFrameSideData *target)
> +{
> +    for (int i = *nb_sd - 1; i >= 0; i--) {
> +        AVFrameSideData *entry = ((*sd)[i]);
> +        if (entry != target)
> +            continue;
> +
> +        free_side_data(&entry);
> +
> +        ((*sd)[i]) = ((*sd)[*nb_sd - 1]);
> +        (*nb_sd)--;
> +
> +        return;
> +    }
> +}
> +
>   AVFrame *av_frame_alloc(void)
>   {
>       AVFrame *frame = av_malloc(sizeof(*frame));
> @@ -764,6 +781,38 @@ AVFrameSideData *av_frame_side_data_new(AVFrameSideData ***sd, int *nb_sd,
>       return ret;
>   }
>   
> +int av_frame_side_data_clone(AVFrameSideData ***sd, int *nb_sd,
> +                             const AVFrameSideData *src, unsigned int flags)
> +{
> +    AVBufferRef     *buf    = NULL;
> +    AVFrameSideData *sd_dst = NULL;
> +    int              ret    = AVERROR_BUG;
> +
> +    if (!sd || !src || !nb_sd || (*nb_sd && !*sd))
> +        return AVERROR(EINVAL);
> +
> +    buf = av_buffer_ref(src->buf);
> +    if (!buf)
> +        return AVERROR(ENOMEM);
> +
> +    if (flags & AV_FRAME_SIDE_DATA_FLAG_UNIQUE)
> +        remove_side_data(sd, nb_sd, src->type);
> +
> +    sd_dst = add_side_data_to_set_from_buf(sd, nb_sd, src->type, buf);
> +    if (!sd_dst) {
> +        av_buffer_unref(&buf);
> +        return AVERROR(ENOMEM);
> +    }
> +
> +    ret = av_dict_copy(&sd_dst->metadata, src->metadata, 0);
> +    if (ret < 0) {
> +        remove_side_data_by_entry(sd, nb_sd, sd_dst);
> +        return ret;
> +    }
> +
> +    return 0;
> +}
> +
>   AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
>                                           enum AVFrameSideDataType type)
>   {
> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index 5d68d1e7af..ce93421d60 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -1021,6 +1021,26 @@ AVFrameSideData *av_frame_side_data_new(AVFrameSideData ***sd, int *nb_sd,
>                                           enum AVFrameSideDataType type,
>                                           size_t size, unsigned int flags);
>   
> +/**
> + * Add a new side data entry to an array based on existing side data, taking
> + * a reference towards the contained AVBufferRef.
> + *
> + * @param sd    pointer to array of side data to which to add another entry,
> + *              or to NULL in order to start a new array.
> + * @param nb_sd pointer to an integer containing the number of entries in
> + *              the array.
> + * @param src   side data to be cloned, with a new reference utilized
> + *              for the buffer.
> + * @param flags Some combination of AV_FRAME_SIDE_DATA_FLAG_* flags, or 0.
> + *
> + * @return negative error code on failure, >=0 on success. In case of
> + *         AV_FRAME_SIDE_DATA_FLAG_UNIQUE being set, entries of matching
> + *         AVFrameSideDataType will be removed before the addition is
> + *         attempted.
> + */
> +int av_frame_side_data_clone(AVFrameSideData ***sd, int *nb_sd,
> +                             const AVFrameSideData *src, unsigned int flags);
> +
>   /**
>    * @}
>    */

Patches 1 to 6 LGTM.