| /* |
| * 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 AVBitStreamFilter ff_dca_core_bsf = { |
| .name = "dca_core", |
| .filter = dca_core_filter, |
| .codec_ids = codec_ids, |
| }; |