[FFmpeg-devel] [PATCH] avutil/frame: Add av_frame_transfer_side_data() function

Lynne dev at lynne.ee
Mon Dec 6 21:12:31 EET 2021


6 Dec 2021, 19:37 by anton at khirnov.net:

> From: Soft Works <softworkz at hotmail.com>
>
> Signed-off-by: softworkz <softworkz at hotmail.com>
> Signed-off-by: Anton Khirnov <anton at khirnov.net>
> ---
>  doc/APIchanges      |  4 +++
>  libavutil/frame.c   | 63 ++++++++++++++++++++++++++-------------------
>  libavutil/frame.h   | 20 ++++++++++++++
>  libavutil/version.h |  4 +--
>  4 files changed, 63 insertions(+), 28 deletions(-)
>
> - renamed the function to av_frame_transfer_side_data(), since actually
>  copying side data is only one of the two possible modes of behavior
>  (and not even the default one)
> - renamed flags accordingly
> - added the AV_FRAME_TRANSFER_SD_FILTER flags as discussed
>
> diff --git a/doc/APIchanges b/doc/APIchanges
> index 2914ad6734..79cfea00b8 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -14,6 +14,10 @@ libavutil:     2021-04-27
>  
>  API changes, most recent first:
>  
> +2021-12-02 - xxxxxxxxxx - lavu 57.11.100 - frame.h
> +  Add av_frame_transfer_side_data(), AV_FRAME_TRANSFER_SD_COPY, and
> +  AV_FRAME_TRANSFER_SD_FILTER.
> +
>  2021-11-xx - xxxxxxxxxx - lavfi 8.19.100 - avfilter.h
>  Add AVFILTER_FLAG_METADATA_ONLY.
>  
> diff --git a/libavutil/frame.c b/libavutil/frame.c
> index 0912ad9131..0b087cc4c9 100644
> --- a/libavutil/frame.c
> +++ b/libavutil/frame.c
> @@ -253,9 +253,40 @@ int av_frame_get_buffer(AVFrame *frame, int align)
>  return AVERROR(EINVAL);
>  }
>  
> +int av_frame_transfer_side_data(AVFrame *dst, const AVFrame *src, int flags)
> +{
> +    for (unsigned i = 0; i < src->nb_side_data; i++) {
> +        const AVFrameSideData *sd_src = src->side_data[i];
> +        AVFrameSideData *sd_dst;
> +        if ((flags & AV_FRAME_TRANSFER_SD_FILTER) &&
> +            sd_src->type == AV_FRAME_DATA_PANSCAN          &&
> +            (src->width != dst->width || src->height != dst->height))
> +            continue;
> +        if (flags & AV_FRAME_TRANSFER_SD_COPY) {
> +            sd_dst = av_frame_new_side_data(dst, sd_src->type,
> +                                            sd_src->size);
> +            if (!sd_dst) {
> +                wipe_side_data(dst);
> +                return AVERROR(ENOMEM);
> +            }
> +            memcpy(sd_dst->data, sd_src->data, sd_src->size);
> +        } else {
> +            AVBufferRef *ref = av_buffer_ref(sd_src->buf);
> +            sd_dst = av_frame_new_side_data_from_buf(dst, sd_src->type, ref);
> +            if (!sd_dst) {
> +                av_buffer_unref(&ref);
> +                wipe_side_data(dst);
> +                return AVERROR(ENOMEM);
> +            }
> +        }
> +        av_dict_copy(&sd_dst->metadata, sd_src->metadata, 0);
> +    }
> +    return 0;
> +}
> +
>  static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
>  {
> -    int ret, i;
> +    int ret;
>  
>  dst->key_frame              = src->key_frame;
>  dst->pict_type              = src->pict_type;
> @@ -291,31 +322,11 @@ static int frame_copy_props(AVFrame *dst, const AVFrame *src, int force_copy)
>  
>  av_dict_copy(&dst->metadata, src->metadata, 0);
>  
> -    for (i = 0; i < src->nb_side_data; i++) {
> -        const AVFrameSideData *sd_src = src->side_data[i];
> -        AVFrameSideData *sd_dst;
> -        if (   sd_src->type == AV_FRAME_DATA_PANSCAN
> -            && (src->width != dst->width || src->height != dst->height))
> -            continue;
> -        if (force_copy) {
> -            sd_dst = av_frame_new_side_data(dst, sd_src->type,
> -                                            sd_src->size);
> -            if (!sd_dst) {
> -                wipe_side_data(dst);
> -                return AVERROR(ENOMEM);
> -            }
> -            memcpy(sd_dst->data, sd_src->data, sd_src->size);
> -        } else {
> -            AVBufferRef *ref = av_buffer_ref(sd_src->buf);
> -            sd_dst = av_frame_new_side_data_from_buf(dst, sd_src->type, ref);
> -            if (!sd_dst) {
> -                av_buffer_unref(&ref);
> -                wipe_side_data(dst);
> -                return AVERROR(ENOMEM);
> -            }
> -        }
> -        av_dict_copy(&sd_dst->metadata, sd_src->metadata, 0);
> -    }
> +    ret = av_frame_transfer_side_data(dst, src,
> +            (force_copy ? AV_FRAME_TRANSFER_SD_COPY : 0) |
> +            AV_FRAME_TRANSFER_SD_FILTER);
> +    if (ret < 0)
> +        return ret;
>  
>  ret = av_buffer_replace(&dst->opaque_ref, src->opaque_ref);
>  ret |= av_buffer_replace(&dst->private_ref, src->private_ref);
> diff --git a/libavutil/frame.h b/libavutil/frame.h
> index 3f295f6b9e..deb399f1da 100644
> --- a/libavutil/frame.h
> +++ b/libavutil/frame.h
> @@ -873,6 +873,26 @@ AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
>  */
>  void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
>  
> +/**
> + * Copy side data, rather than creating new references.
> + */
> +#define AV_FRAME_TRANSFER_SD_COPY      (1 << 0)
> +/**
> + * Filter out side data that does not match dst properties.
> + */
> +#define AV_FRAME_TRANSFER_SD_FILTER    (1 << 1)
> +
> +/**
> + * Transfer all side-data from src to dst.
> + *
> + * @param flags a combination of AV_FRAME_TRANSFER_SD_*
> + *
> + * @return >= 0 on success, a negative AVERROR on error.
> + *
> + * @note This function will create new references to side data buffers in src,
> + * unless the AV_FRAME_TRANSFER_SD_COPY flag is passed.
> + */
> +int av_frame_transfer_side_data(AVFrame *dst, const AVFrame *src, int flags);
>  
>  /**
>  * Flags for frame cropping.
> diff --git a/libavutil/version.h b/libavutil/version.h
> index 017fc277a6..0e7b36865a 100644
> --- a/libavutil/version.h
> +++ b/libavutil/version.h
> @@ -79,8 +79,8 @@
>  */
>  
>  #define LIBAVUTIL_VERSION_MAJOR  57
> -#define LIBAVUTIL_VERSION_MINOR  10
> -#define LIBAVUTIL_VERSION_MICRO 101
> +#define LIBAVUTIL_VERSION_MINOR  11
> +#define LIBAVUTIL_VERSION_MICRO 100
>  
>  #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
>  LIBAVUTIL_VERSION_MINOR, \
>

I think av_frame_copy_side_data() makes more sense. Transfer
implies that it strips the source frame of side data.


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