/*

 * 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 "bytestream.h"

#include "h2645_parse.h"

#include "hevc.h"

#include "parse.h"

static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets *ps,

                                 HEVCSEI *sei, int is_nalff, int nal_length_size,

                                 int err_recognition, int apply_defdispwin, void *logctx)

{

    int i;

    int ret = 0;

    int flags = (H2645_FLAG_IS_NALFF * !!is_nalff) | H2645_FLAG_SMALL_PADDING;

    H2645Packet pkt = { 0 };

    ret = ff_h2645_packet_split(&pkt, buf, buf_size, logctx,

                                nal_length_size, AV_CODEC_ID_HEVC, flags);

    if (ret < 0) {

        goto done;

    }

    for (i = 0; i < pkt.nb_nals; i++) {

        H2645NAL *nal = &pkt.nals[i];

        if (nal->nuh_layer_id > 0)

            continue;

        /* ignore everything except parameter sets and VCL NALUs */

        switch (nal->type) {

        case HEVC_NAL_VPS:

            ret = ff_hevc_decode_nal_vps(&nal->gb, logctx, ps);

            if (ret < 0)

                goto done;

            break;

        case HEVC_NAL_SPS:

            ret = ff_hevc_decode_nal_sps(&nal->gb, logctx, ps, apply_defdispwin);

            if (ret < 0)

                goto done;

            break;

        case HEVC_NAL_PPS:

            ret = ff_hevc_decode_nal_pps(&nal->gb, logctx, ps);

            if (ret < 0)

                goto done;

            break;

        case HEVC_NAL_SEI_PREFIX:

        case HEVC_NAL_SEI_SUFFIX:

            ret = ff_hevc_decode_nal_sei(&nal->gb, logctx, sei, ps, nal->type);

            if (ret < 0)

                goto done;

            break;

        default:

            av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n", nal->type);

            break;

        }

    }

done:

    ff_h2645_packet_uninit(&pkt);

    if (err_recognition & AV_EF_EXPLODE)

        return ret;

    return 0;

}

int ff_hevc_decode_extradata(const uint8_t *data, int size, HEVCParamSets *ps,

                             HEVCSEI *sei, int *is_nalff, int *nal_length_size,

                             int err_recognition, int apply_defdispwin, void *logctx)

{

    int ret = 0;

    GetByteContext gb;

    bytestream2_init(&gb, data, size);

    /* data[0] == 1 is configurationVersion from 14496-15.

     * data[0] == 0 is for backward compatibility predates the standard.

     *

     * Minimum number of bytes of hvcC with 0 numOfArrays is 23.

     */

    if (size >= 23 && ((data[0] == 1) || (data[0] == 0 && (data[1] || data[2] > 1)))) {

        /* It seems the extradata is encoded as hvcC format. */

        int i, j, num_arrays, nal_len_size;

        *is_nalff = 1;

        bytestream2_skip(&gb, 21);

        nal_len_size = (bytestream2_get_byte(&gb) & 3) + 1;

        num_arrays   = bytestream2_get_byte(&gb);

        /* nal units in the hvcC always have length coded with 2 bytes,

         * so put a fake nal_length_size = 2 while parsing them */

        *nal_length_size = 2;

        /* Decode nal units from hvcC. */

        for (i = 0; i < num_arrays; i++) {

            int type = bytestream2_get_byte(&gb) & 0x3f;

            int cnt  = bytestream2_get_be16(&gb);

            for (j = 0; j < cnt; j++) {

                // +2 for the nal size field

                int nalsize = bytestream2_peek_be16(&gb) + 2;

                if (bytestream2_get_bytes_left(&gb) < nalsize) {

                    av_log(logctx, AV_LOG_ERROR,

                           "Invalid NAL unit size in extradata.\n");

                    return AVERROR_INVALIDDATA;

                }

                ret = hevc_decode_nal_units(gb.buffer, nalsize, ps, sei, *is_nalff,

                                            *nal_length_size, err_recognition, apply_defdispwin,

                                            logctx);

                if (ret < 0) {

                    av_log(logctx, AV_LOG_ERROR,

                           "Decoding nal unit %d %d from hvcC failed\n",

                           type, i);

                    return ret;

                }

                bytestream2_skip(&gb, nalsize);

            }

        }

        /* Now store right nal length size, that will be used to parse

         * all other nals */

        *nal_length_size = nal_len_size;

    } else {

        *is_nalff = 0;

        ret = hevc_decode_nal_units(data, size, ps, sei, *is_nalff, *nal_length_size,

                                    err_recognition, apply_defdispwin, logctx);

        if (ret < 0)

            return ret;

    }

    return ret;

}