[FFmpeg-devel] [PATCH v22 02/23] avutil/frame: Prepare AVFrame for subtitle handling

[Andreas Rheinhardt]

Soft Works:
> Root commit for adding subtitle filtering capabilities.
> In detail:
> 
> - Add type (AVMediaType) field to AVFrame
>   Replaces previous way of distinction which was based on checking
>   width and height to determine whether a frame is audio or video
> - Add subtitle fields to AVFrame
> - Add new struct AVSubtitleArea, similar to AVSubtitleRect, but different
>   allocation logic. Cannot and must not be used interchangeably, hence
>   the new struct
> 
> Signed-off-by: softworkz <softworkz at hotmail.com>
> ---
>  libavutil/Makefile |   1 +
>  libavutil/frame.c  | 211 ++++++++++++++++++++++++++++++++++++++++-----
>  libavutil/frame.h  |  78 ++++++++++++++++-
>  libavutil/subfmt.c |  50 +++++++++++
>  libavutil/subfmt.h |  48 +++++++++++
>  5 files changed, 364 insertions(+), 24 deletions(-)
>  create mode 100644 libavutil/subfmt.c
> 
> diff --git a/libavutil/subfmt.c b/libavutil/subfmt.c
> new file mode 100644
> index 0000000000..3998a6d486
> --- /dev/null
> +++ b/libavutil/subfmt.c
> @@ -0,0 +1,50 @@
> +/*
> + * Copyright (c) 2021 softworkz
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <string.h>
> +#include "common.h"
> +#include "subfmt.h"
> +
> +typedef struct SubtitleFmtInfo {
> +    enum AVSubtitleType fmt;
> +    const char* name;
> +} SubtitleFmtInfo;

This struct is unused now.

> +
> +static const char sub_fmt_info[AV_SUBTITLE_FMT_NB][24] = {
> +    [AV_SUBTITLE_FMT_UNKNOWN] = "Unknown subtitle format",
> +    [AV_SUBTITLE_FMT_BITMAP]  = "Graphical subtitles",
> +    [AV_SUBTITLE_FMT_TEXT]    = "Text subtitles (plain)",
> +    [AV_SUBTITLE_FMT_ASS]     = "Text subtitles (ass)",
> +};
> +
> +const char *av_get_subtitle_fmt_name(enum AVSubtitleType sub_fmt)
> +{
> +    if (sub_fmt < 0 || sub_fmt >= AV_SUBTITLE_FMT_NB)
> +        return NULL;
> +    return sub_fmt_info[sub_fmt];
> +}
> +
> +enum AVSubtitleType av_get_subtitle_fmt(const char *name)
> +{
> +    for (int i = 0; i < AV_SUBTITLE_FMT_NB; i++)
> +        if (!strcmp(sub_fmt_info[i], name))
> +            return i;
> +    return AV_SUBTITLE_FMT_NONE;
> +}