[FFmpeg-devel] [PATCH 3/5] avdevice/lavfi: Use av_packet_pack_dictionary() to pack dictionary

[Andreas Rheinhardt]

Andreas Rheinhardt:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
> av_packet_pack_dictionary() returns NULL in case the dictionary's count
> is zero; but given that the dict API does not return such dicts at all,
> I have not added any check for this.
> 
>  libavdevice/lavfi.c | 25 ++++++++-----------------
>  1 file changed, 8 insertions(+), 17 deletions(-)
> 
> diff --git a/libavdevice/lavfi.c b/libavdevice/lavfi.c
> index 5e814eada8..bafc3275c9 100644
> --- a/libavdevice/lavfi.c
> +++ b/libavdevice/lavfi.c
> @@ -444,25 +444,16 @@ static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
>  
>      frame_metadata = frame->metadata;
>      if (frame_metadata) {
> -        uint8_t *metadata;
> -        AVDictionaryEntry *e = NULL;
> -        AVBPrint meta_buf;
> -
> -        av_bprint_init(&meta_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
> -        while ((e = av_dict_get(frame_metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
> -            av_bprintf(&meta_buf, "%s", e->key);
> -            av_bprint_chars(&meta_buf, '\0', 1);
> -            av_bprintf(&meta_buf, "%s", e->value);
> -            av_bprint_chars(&meta_buf, '\0', 1);
> -        }
> -        if (!av_bprint_is_complete(&meta_buf) ||
> -            !(metadata = av_packet_new_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
> -                                                 meta_buf.len))) {
> -            av_bprint_finalize(&meta_buf, NULL);
> +        int size;
> +        uint8_t *metadata = av_packet_pack_dictionary(frame_metadata, &size);
> +
> +        if (!metadata)
>              return AVERROR(ENOMEM);
> +        if ((ret = av_packet_add_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
> +                                           metadata, size)) < 0) {
> +            av_freep(&metadata);
> +            return ret;
>          }
> -        memcpy(metadata, meta_buf.str, meta_buf.len);
> -        av_bprint_finalize(&meta_buf, NULL);
>      }
>  
>      if ((ret = create_subcc_packet(avctx, frame, min_pts_sink_idx)) < 0) {
> 
Will apply the two outstanding patches (i.e. this and 4/5 [1]) of this
patchset tomorrow unless there are objections.

- Andreas

[1]: https://ffmpeg.org/pipermail/ffmpeg-devel/2020-August/268930.html