/*

 * FTR parser

 * Copyright (c) 2022 Paul B Mahol

 *

 * 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

 */

/**

 * @file

 * FTR parser

 */

#include "parser.h"

#include "adts_header.h"

#include "adts_parser.h"

#include "mpeg4audio.h"

#include "parser_internal.h"

typedef struct FTRParseContext {

    ParseContext pc;

    int skip;

    int split;

    int frame_index;

} FTRParseContext;

static int ftr_parse(AVCodecParserContext *s, AVCodecContext *avctx,

                     const uint8_t **poutbuf, int *poutbuf_size,

                     const uint8_t *buf, int buf_size)

{

    uint8_t tmp[8 + AV_INPUT_BUFFER_PADDING_SIZE];

    FTRParseContext *ftr = s->priv_data;

    uint64_t state = ftr->pc.state64;

    int next = END_NOT_FOUND;

    AACADTSHeaderInfo hdr;

    int size;

    *poutbuf_size = 0;

    *poutbuf = NULL;

    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {

        next = buf_size;

    } else {

        for (int i = 0; i < buf_size; i++) {

            if (ftr->skip > 0) {

                ftr->skip--;

                if (ftr->skip == 0 && ftr->split) {

                    ftr->split = 0;

                    next = i;

                    s->duration = 1024;

                    s->key_frame = 1;

                    break;

                } else if (ftr->skip > 0) {

                    continue;

                }

            }

            state = (state << 8) | buf[i];

            AV_WB64(tmp, state);

            size = ff_adts_header_parse_buf(tmp + 8 - AV_AAC_ADTS_HEADER_SIZE, &hdr);

            if (size > 0) {

                ftr->skip = size - 6;

                ftr->frame_index += ff_mpeg4audio_channels[hdr.chan_config];

                if (ftr->frame_index >= avctx->ch_layout.nb_channels) {

                    ftr->frame_index = 0;

                    ftr->split = 1;

                }

            }

        }

        ftr->pc.state64 = state;

        if (ff_combine_frame(&ftr->pc, next, &buf, &buf_size) < 0) {

            *poutbuf = NULL;

            *poutbuf_size = 0;

            return buf_size;

        }

    }

    *poutbuf      = buf;

    *poutbuf_size = buf_size;

    return next;

}

const FFCodecParser ff_ftr_parser = {

    PARSER_CODEC_LIST(AV_CODEC_ID_FTR),

    .priv_data_size = sizeof(FTRParseContext),

    .parse          = ftr_parse,

    .close          = ff_parse_close,

};