From 2974b2556b2dae1347c9bee2ddc11c0d101a6d79 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Tue, 27 Mar 2018 16:47:24 +0200 Subject: [PATCH] avcodec: add eac3_core bitstream filter Signed-off-by: Paul B Mahol --- Changelog | 1 + doc/bitstream_filters.texi | 4 ++ libavcodec/Makefile | 1 + libavcodec/bitstream_filters.c | 1 + libavcodec/eac3_core_bsf.c | 86 ++++++++++++++++++++++++++++++++++ 5 files changed, 93 insertions(+) create mode 100644 libavcodec/eac3_core_bsf.c diff --git a/Changelog b/Changelog index 41a18056dd..2869dce386 100644 --- a/Changelog +++ b/Changelog @@ -50,6 +50,7 @@ version : - filter_units bitstream filter - AV1 Support through libaom - E-AC-3 dependent frames support +- bitstream filter for extracting E-AC-3 core version 3.4: diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi index 982e3edac8..7322af6550 100644 --- a/doc/bitstream_filters.texi +++ b/doc/bitstream_filters.texi @@ -75,6 +75,10 @@ the header stored in extradata to the key packets: ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts @end example +@section eac3_core + +Extract the core from a E-AC-3 stream, dropping extra channels. + @section extract_extradata Extract the in-band extradata. diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 404047d335..4b8ad121db 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -1043,6 +1043,7 @@ OBJS-$(CONFIG_AAC_ADTSTOASC_BSF) += aac_adtstoasc_bsf.o mpeg4audio.o OBJS-$(CONFIG_CHOMP_BSF) += chomp_bsf.o OBJS-$(CONFIG_DUMP_EXTRADATA_BSF) += dump_extradata_bsf.o OBJS-$(CONFIG_DCA_CORE_BSF) += dca_core_bsf.o +OBJS-$(CONFIG_EAC3_CORE_BSF) += eac3_core_bsf.o OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF) += extract_extradata_bsf.o \ h2645_parse.o OBJS-$(CONFIG_FILTER_UNITS_BSF) += filter_units_bsf.o diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c index 12211225bb..18b698a85f 100644 --- a/libavcodec/bitstream_filters.c +++ b/libavcodec/bitstream_filters.c @@ -28,6 +28,7 @@ extern const AVBitStreamFilter ff_aac_adtstoasc_bsf; extern const AVBitStreamFilter ff_chomp_bsf; extern const AVBitStreamFilter ff_dump_extradata_bsf; extern const AVBitStreamFilter ff_dca_core_bsf; +extern const AVBitStreamFilter ff_eac3_core_bsf; extern const AVBitStreamFilter ff_extract_extradata_bsf; extern const AVBitStreamFilter ff_filter_units_bsf; extern const AVBitStreamFilter ff_h264_metadata_bsf; diff --git a/libavcodec/eac3_core_bsf.c b/libavcodec/eac3_core_bsf.c new file mode 100644 index 0000000000..3e4dc2e2a2 --- /dev/null +++ b/libavcodec/eac3_core_bsf.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2018 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 "avcodec.h" +#include "bsf.h" +#include "get_bits.h" +#include "ac3_parser_internal.h" + +static int eac3_core_filter(AVBSFContext *ctx, AVPacket *pkt) +{ + AC3HeaderInfo hdr; + GetBitContext gbc; + int ret; + + ret = ff_bsf_get_packet_ref(ctx, pkt); + if (ret < 0) + return ret; + ret = init_get_bits8(&gbc, pkt->data, pkt->size); + if (ret < 0) + goto fail; + + ret = ff_ac3_parse_header(&gbc, &hdr); + if (ret < 0) { + ret = AVERROR_INVALIDDATA; + goto fail; + } + + if (hdr.frame_type == EAC3_FRAME_TYPE_INDEPENDENT || + hdr.frame_type == EAC3_FRAME_TYPE_AC3_CONVERT) { + pkt->size = FFMIN(hdr.frame_size, pkt->size); + } else if (hdr.frame_type == EAC3_FRAME_TYPE_DEPENDENT && pkt->size > hdr.frame_size) { + AC3HeaderInfo hdr2; + + ret = init_get_bits8(&gbc, pkt->data + hdr.frame_size, pkt->size - hdr.frame_size); + if (ret < 0) + goto fail; + + ret = ff_ac3_parse_header(&gbc, &hdr2); + if (ret < 0) { + ret = AVERROR_INVALIDDATA; + goto fail; + } + + if (hdr2.frame_type == EAC3_FRAME_TYPE_INDEPENDENT || + hdr2.frame_type == EAC3_FRAME_TYPE_AC3_CONVERT) { + pkt->size -= hdr.frame_size; + pkt->data += hdr.frame_size; + } else { + pkt->size = 0; + } + } else { + pkt->size = 0; + } + + return 0; +fail: + av_packet_unref(pkt); + return ret; +} + +static const enum AVCodecID codec_ids[] = { + AV_CODEC_ID_EAC3, AV_CODEC_ID_NONE, +}; + +const AVBitStreamFilter ff_eac3_core_bsf = { + .name = "eac3_core", + .filter = eac3_core_filter, + .codec_ids = codec_ids, +};