[FFmpeg-devel] [PATCH 2/2] avcodec/dolby_e: Split decoder/parser files

[James Almer]

On 1/25/2021 9:11 AM, Nicolas Gaullier wrote:
> ---
>   libavcodec/Makefile                  |   1 +
>   libavcodec/dolby_e.c                 | 149 +------
>   libavcodec/dolby_e.h                 | 598 +-------------------------
>   libavcodec/dolby_e_parser.c          | 227 ++++++++++
>   libavcodec/dolby_e_parser.h          |  41 ++
>   libavcodec/dolby_e_parser_internal.h |  46 ++
>   libavcodec/dolby_edec.h              | 607 +++++++++++++++++++++++++++
>   7 files changed, 932 insertions(+), 737 deletions(-)
>   create mode 100644 libavcodec/dolby_e_parser.c
>   create mode 100644 libavcodec/dolby_e_parser.h
>   create mode 100644 libavcodec/dolby_e_parser_internal.h
>   create mode 100644 libavcodec/dolby_edec.h
> 
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index d48fecc5fc..633ebc37f8 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -40,6 +40,7 @@ OBJS = ac3_parser.o                                                     \
>          d3d11va.o                                                        \
>          decode.o                                                         \
>          dirac.o                                                          \
> +       dolby_e_parser.o                                                 \

Don't compile it unconditionally.

>          dv_profile.o                                                     \
>          encode.o                                                         \
>          imgconvert.o                                                     \

[...]

> diff --git a/libavcodec/dolby_e_parser.h b/libavcodec/dolby_e_parser.h
> new file mode 100644
> index 0000000000..2f9a2b2ebb
> --- /dev/null
> +++ b/libavcodec/dolby_e_parser.h
> @@ -0,0 +1,41 @@
> +/*
> + * Copyright (C) 2017 foo86
> + *
> + * 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
> + */
> +
> +#ifndef AVCODEC_DOLBY_E_PARSER_H
> +#define AVCODEC_DOLBY_E_PARSER_H
> +
> +#include "dolby_e.h"
> +
> +typedef struct DBEParseContext {
> +    ParseContext pc;
> +    DBEContext dectx;
> +
> +    DolbyEHeaderInfo metadata;
> +} DBEParseContext;
> +
> +static const uint8_t nb_programs_tab[MAX_PROG_CONF + 1] = {
> +    2, 3, 2, 3, 4, 5, 4, 5, 6, 7, 8, 1, 2, 3, 3, 4, 5, 6, 1, 2, 3, 4, 1, 1
> +};
> +
> +static const uint8_t nb_channels_tab[MAX_PROG_CONF + 1] = {
> +    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 6, 6, 6, 6, 6, 6, 6, 4, 4, 4, 4, 8, 8
> +};

This header doesn't seem to be needed at all. Just add the struct and 
both arrays to dolby_e_parser.c

> +
> +#endif
> diff --git a/libavcodec/dolby_e_parser_internal.h b/libavcodec/dolby_e_parser_internal.h
> new file mode 100644
> index 0000000000..defd1f97d6
> --- /dev/null
> +++ b/libavcodec/dolby_e_parser_internal.h

This name is odd, as it implies the other header is public, which is not.
Try to follow instead what codecs like h264, hevc, and mlp do. There's 
the decoder, the parser, and then a separate source file that is shared 
by both. That way, neither the decoder or parser depend on each other.

dolby_e.c/h - Decoder only functions, tables and structures. Compiled 
when the decoder is enabled.
dolby_e_parser.c - Parser only functions, tables and structures. 
Compiled when the parser is enabled.
dolby_e_parse.c/h - Shared functions, tables and structures. Compiled 
when either decoder or parser are enabled.