FFmpeg
libavcodec
eac3_core_bsf.c
Go to the documentation of this file.
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/*
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* Copyright (c) 2018 Paul B Mahol
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "
bsf.h
"
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#include "
bsf_internal.h
"
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#include "
get_bits.h
"
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#include "
ac3_parser_internal.h
"
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static
int
eac3_core_filter
(
AVBSFContext
*
ctx
,
AVPacket
*
pkt
)
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{
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AC3HeaderInfo
hdr;
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GetBitContext
gbc;
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int
ret
;
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ret
=
ff_bsf_get_packet_ref
(
ctx
,
pkt
);
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if
(
ret
< 0)
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return
ret
;
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ret
=
init_get_bits8
(&gbc,
pkt
->
data
,
pkt
->
size
);
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if
(
ret
< 0)
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goto
fail
;
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ret
=
ff_ac3_parse_header
(&gbc, &hdr);
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if
(
ret
< 0) {
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ret
=
AVERROR_INVALIDDATA
;
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goto
fail
;
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}
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if
(hdr.
frame_type
==
EAC3_FRAME_TYPE_INDEPENDENT
||
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hdr.
frame_type
==
EAC3_FRAME_TYPE_AC3_CONVERT
) {
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pkt
->
size
=
FFMIN
(hdr.
frame_size
,
pkt
->
size
);
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}
else
if
(hdr.
frame_type
==
EAC3_FRAME_TYPE_DEPENDENT
&&
pkt
->
size
> hdr.
frame_size
) {
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AC3HeaderInfo
hdr2;
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ret
=
init_get_bits8
(&gbc,
pkt
->
data
+ hdr.
frame_size
,
pkt
->
size
- hdr.
frame_size
);
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if
(
ret
< 0)
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goto
fail
;
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ret
=
ff_ac3_parse_header
(&gbc, &hdr2);
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if
(
ret
< 0) {
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ret
=
AVERROR_INVALIDDATA
;
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goto
fail
;
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}
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if
(hdr2.
frame_type
==
EAC3_FRAME_TYPE_INDEPENDENT
||
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hdr2.
frame_type
==
EAC3_FRAME_TYPE_AC3_CONVERT
) {
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pkt
->
size
-= hdr.
frame_size
;
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pkt
->
data
+= hdr.
frame_size
;
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}
else
{
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pkt
->
size
= 0;
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}
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}
else
{
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pkt
->
size
= 0;
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}
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return
0;
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fail
:
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av_packet_unref
(
pkt
);
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return
ret
;
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}
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static
const
enum
AVCodecID
codec_ids
[] = {
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AV_CODEC_ID_EAC3
,
AV_CODEC_ID_NONE
,
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};
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const
FFBitStreamFilter
ff_eac3_core_bsf
= {
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.
p
.
name
=
"eac3_core"
,
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.p.codec_ids =
codec_ids
,
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.filter =
eac3_core_filter
,
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};
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition:
avpacket.c:426
AC3HeaderInfo::frame_type
uint8_t frame_type
Definition:
ac3_parser_internal.h:45
bsf_internal.h
AVBitStreamFilter::name
const char * name
Definition:
bsf.h:112
AVPacket::data
uint8_t * data
Definition:
packet.h:515
AVBSFContext
The bitstream filter state.
Definition:
bsf.h:68
ff_eac3_core_bsf
const FFBitStreamFilter ff_eac3_core_bsf
Definition:
eac3_core_bsf.c:82
bsf.h
fail
#define fail()
Definition:
checkasm.h:177
GetBitContext
Definition:
get_bits.h:109
AC3HeaderInfo
Definition:
ac3_parser_internal.h:34
AC3HeaderInfo::frame_size
uint16_t frame_size
Definition:
ac3_parser_internal.h:61
EAC3_FRAME_TYPE_DEPENDENT
@ EAC3_FRAME_TYPE_DEPENDENT
Definition:
ac3defs.h:99
pkt
AVPacket * pkt
Definition:
movenc.c:59
eac3_core_filter
static int eac3_core_filter(AVBSFContext *ctx, AVPacket *pkt)
Definition:
eac3_core_bsf.c:26
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition:
get_bits.h:546
EAC3_FRAME_TYPE_INDEPENDENT
@ EAC3_FRAME_TYPE_INDEPENDENT
Definition:
ac3defs.h:98
ctx
AVFormatContext * ctx
Definition:
movenc.c:48
get_bits.h
FFBitStreamFilter
Definition:
bsf_internal.h:27
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition:
codec_id.h:49
AV_CODEC_ID_EAC3
@ AV_CODEC_ID_EAC3
Definition:
codec_id.h:483
EAC3_FRAME_TYPE_AC3_CONVERT
@ EAC3_FRAME_TYPE_AC3_CONVERT
Definition:
ac3defs.h:100
FFBitStreamFilter::p
AVBitStreamFilter p
The public AVBitStreamFilter.
Definition:
bsf_internal.h:31
ac3_parser_internal.h
AVPacket::size
int size
Definition:
packet.h:516
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition:
codec_id.h:50
FFMIN
#define FFMIN(a, b)
Definition:
macros.h:49
ret
ret
Definition:
filter_design.txt:187
ff_ac3_parse_header
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
Parse AC-3 frame header.
AVPacket
This structure stores compressed data.
Definition:
packet.h:492
ff_bsf_get_packet_ref
int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
Called by bitstream filters to get packet for filtering.
Definition:
bsf.c:256
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition:
error.h:61
codec_ids
static enum AVCodecID codec_ids[]
Definition:
eac3_core_bsf.c:78
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