@@ -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.
@@ -1041,6 +1041,7 @@ 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
@@ -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;
new file mode 100644
@@ -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 = hdr.frame_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,
+};
Signed-off-by: Paul B Mahol <onemda@gmail.com> --- doc/bitstream_filters.texi | 4 ++ libavcodec/Makefile | 1 + libavcodec/bitstream_filters.c | 1 + libavcodec/eac3_core_bsf.c | 86 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 92 insertions(+) create mode 100644 libavcodec/eac3_core_bsf.c