/* * Copyright (c) 2016 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 */ #include "bsf.h"#include "bsf_internal.h"#include "bytestream.h"#include "dca_syncwords.h" static int dca_core_filter(AVBSFContext *ctx, AVPacket *pkt){    GetByteContext gb;    uint32_t syncword;    int core_size = 0, ret;     ret = ff_bsf_get_packet_ref(ctx, pkt);    if (ret < 0)        return ret;     bytestream2_init(&gb, pkt->data, pkt->size);    syncword = bytestream2_get_be32(&gb);    bytestream2_skip(&gb, 1);     switch (syncword) {    case DCA_SYNCWORD_CORE_BE:        core_size = ((bytestream2_get_be24(&gb) >> 4) & 0x3fff) + 1;        break;    }     if (core_size > 0 && core_size <= pkt->size) {        pkt->size = core_size;    }     return 0;} static const enum AVCodecID codec_ids[] = {    AV_CODEC_ID_DTS, AV_CODEC_ID_NONE,}; const FFBitStreamFilter ff_dca_core_bsf = {    .p.name      = "dca_core",    .p.codec_ids = codec_ids,    .filter      = dca_core_filter,};