[FFmpeg-devel] [PATCH v5 3/4] lavc: add avs2 parser

[Steven Liu]

hwren <hwrenx at 126.com> 于2018年7月3日周二 上午10:34写道：
>
> Signed-off-by: hwren <hwrenx at 126.com>
> ---
>  libavcodec/Makefile      |  1 +
>  libavcodec/avs2_parser.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
>  libavcodec/parser.c      |  1 +
>  3 files changed, 97 insertions(+)
>  create mode 100644 libavcodec/avs2_parser.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 3ab071a..6b6d6de 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -994,6 +994,7 @@ OBJS-$(CONFIG_AAC_PARSER)              += aac_parser.o aac_ac3_parser.o \
>                                            mpeg4audio.o
>  OBJS-$(CONFIG_AC3_PARSER)              += ac3tab.o aac_ac3_parser.o
>  OBJS-$(CONFIG_ADX_PARSER)              += adx_parser.o adx.o
> +OBJS-$(CONFIG_AVS2_PARSER)             += avs2_parser.o
>  OBJS-$(CONFIG_BMP_PARSER)              += bmp_parser.o
>  OBJS-$(CONFIG_CAVSVIDEO_PARSER)        += cavs_parser.o
>  OBJS-$(CONFIG_COOK_PARSER)             += cook_parser.o
> diff --git a/libavcodec/avs2_parser.c b/libavcodec/avs2_parser.c
> new file mode 100644
> index 0000000..0cf57ad
> --- /dev/null
> +++ b/libavcodec/avs2_parser.c
> @@ -0,0 +1,95 @@
> +/*
> + * AVS2/IEEE 1857.4 video parser.
> + * Copyright (c) 2018  Huiwen Ren <hwrenx at gmail.com>
> + *
> + * 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 "parser.h"
> +
> +#define SLICE_MAX_START_CODE    0x000001af
> +
> +#define ISPIC(x)  ((x) == 0xB3 || (x) == 0xB6)
> +#define ISUNIT(x) ((x) == 0xB0 || (x) == 0xB1 || (x) == 0xB2 || ISPIC(x))
> +
> +static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
> +{
> +    int pic_found  = pc->frame_start_found;
> +    uint32_t state = pc->state;
> +    int i = 0;
> +
> +    if (!pic_found) {
> +        for (i = 0; i < buf_size; ++i) {
> +            state = (state<<8) | buf[i];
> +            if (ISUNIT(buf[i])){
> +                ++i;
> +                pic_found = 1;
> +                break;
> +            }
> +        }
> +    }
> +
> +    if (pic_found) {
> +        if (buf_size == 0)
maybe patcheck will give a warning, !buf_size, but this maybe ok too.
> +            return END_NOT_FOUND;
> +        for (; i < buf_size; ++i) {
> +            state = (state << 8) | buf[i];
> +            if ((state & 0xFFFFFF00) == 0x100 && state > SLICE_MAX_START_CODE) {
> +                pc->frame_start_found = 0;
> +                pc->state = -1;
> +                return i - 3;
> +            }
> +        }
> +    }
> +
> +    pc->frame_start_found = pic_found;
> +    pc->state = state;
> +
> +    return END_NOT_FOUND;
> +}
> +
> +static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx,
> +                      const uint8_t **poutbuf, int *poutbuf_size,
> +                      const uint8_t *buf, int buf_size)
> +{
> +    ParseContext *pc = s->priv_data;
> +    int next;
> +
> +    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES)  {
> +        next = buf_size;
> +    } else {
> +        next = avs2_find_frame_end(pc, buf, buf_size);
> +        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
> +            *poutbuf = NULL;
> +            *poutbuf_size = 0;
> +            return buf_size;
> +        }
> +    }
> +
> +    *poutbuf = buf;
> +    *poutbuf_size = buf_size;
> +
> +    return next;
> +}
> +
> +AVCodecParser ff_avs2_parser = {
> +    .codec_ids      = { AV_CODEC_ID_AVS2 },
> +    .priv_data_size = sizeof(ParseContext),
> +    .parser_parse   = avs2_parse,
> +    .parser_close   = ff_parse_close,
> +    .split          = ff_mpeg4video_split,
> +};
> diff --git a/libavcodec/parser.c b/libavcodec/parser.c
> index f43b197..7f8a451 100644
> --- a/libavcodec/parser.c
> +++ b/libavcodec/parser.c
> @@ -37,6 +37,7 @@ extern AVCodecParser ff_aac_parser;
>  extern AVCodecParser ff_aac_latm_parser;
>  extern AVCodecParser ff_ac3_parser;
>  extern AVCodecParser ff_adx_parser;
> +extern AVCodecParser ff_avs2_parser;
>  extern AVCodecParser ff_bmp_parser;
>  extern AVCodecParser ff_cavsvideo_parser;
>  extern AVCodecParser ff_cook_parser;
> --
> 2.7.4
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel