FFmpeg
h264_redundant_pps.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
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8  *
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12  * Lesser General Public License for more details.
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16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <inttypes.h>
20 
21 #include "libavutil/log.h"
22 
23 #include "bsf.h"
24 #include "bsf_internal.h"
25 #include "cbs.h"
26 #include "cbs_bsf.h"
27 #include "cbs_h264.h"
28 #include "codec_id.h"
29 #include "h264.h"
30 #include "packet.h"
31 
32 #define NEW_GLOBAL_PIC_INIT_QP 26
33 
34 typedef struct H264RedundantPPSContext {
37 
38 
40  CodedBitstreamUnit *unit)
41 {
42  H264RawPPS *pps;
43  int err;
44 
45  // The changes we are about to perform affect the parsing process,
46  // so we must make sure that the PPS is writable, otherwise the
47  // parsing of future slices will be incorrect and even raise errors.
48  err = ff_cbs_make_unit_writable(ctx->common.input, unit);
49  if (err < 0)
50  return err;
51  pps = unit->content;
52 
53  // Overwrite pic_init_qp with the global value.
54  pps->pic_init_qp_minus26 = NEW_GLOBAL_PIC_INIT_QP - 26;
55 
56  // Some PPSs have this set, so it must be set in all of them.
57  // (Slices which do not use such a PPS on input will still have
58  // *_weight_l*flag as zero and therefore write equivalently.)
59  pps->weighted_pred_flag = 1;
60 
61  return 0;
62 }
63 
65  H264RawSliceHeader *slice)
66 {
67  const CodedBitstreamH264Context *const in = ctx->common.input->priv_data;
68  const H264RawPPS *const pps = in->pps[slice->pic_parameter_set_id];
69 
70  // We modified the PPS's qp value, now offset this by applying
71  // the negative offset to the slices.
72  slice->slice_qp_delta += pps->pic_init_qp_minus26
73  - (NEW_GLOBAL_PIC_INIT_QP - 26);
74 
75  return 0;
76 }
77 
79  AVPacket *pkt,
81 {
83  int err, i;
84 
85  for (i = 0; i < au->nb_units; i++) {
86  CodedBitstreamUnit *nal = &au->units[i];
87 
88  if (nal->type == H264_NAL_PPS) {
90  if (err < 0)
91  return err;
92  }
93  if (nal->type == H264_NAL_SLICE ||
94  nal->type == H264_NAL_IDR_SLICE) {
95  H264RawSlice *slice = nal->content;
97  }
98  }
99 
100  return 0;
101 }
102 
105  .fragment_name = "access unit",
106  .unit_name = "NAL unit",
107  .update_fragment = &h264_redundant_pps_update_fragment,
108 };
109 
111 {
113 }
114 
117 };
118 
120  .p.name = "h264_redundant_pps",
121  .p.codec_ids = h264_redundant_pps_codec_ids,
122  .priv_data_size = sizeof(H264RedundantPPSContext),
124  .close = &ff_cbs_bsf_generic_close,
126 };
H264RedundantPPSContext
Definition: h264_redundant_pps.c:34
ff_cbs_bsf_generic_init
int ff_cbs_bsf_generic_init(AVBSFContext *bsf, const CBSBSFType *type)
Initialise generic CBS BSF setup.
Definition: cbs_bsf.c:110
bsf_internal.h
h264_redundant_pps_type
static const CBSBSFType h264_redundant_pps_type
Definition: h264_redundant_pps.c:103
CBSBSFType::codec_id
enum AVCodecID codec_id
Definition: cbs_bsf.h:32
H264_NAL_PPS
@ H264_NAL_PPS
Definition: h264.h:42
cbs_h264.h
CodedBitstreamUnit::content
void * content
Pointer to the decomposed form of this unit.
Definition: cbs.h:107
AVBitStreamFilter::name
const char * name
Definition: bsf.h:112
NEW_GLOBAL_PIC_INIT_QP
#define NEW_GLOBAL_PIC_INIT_QP
Definition: h264_redundant_pps.c:32
CodedBitstreamH264Context::pps
H264RawPPS * pps[H264_MAX_PPS_COUNT]
RefStruct references.
Definition: cbs_h264.h:411
CBSBSFContext
Definition: cbs_bsf.h:53
CodedBitstreamUnit::type
CodedBitstreamUnitType type
Codec-specific type of this unit.
Definition: cbs.h:74
cbs.h
filter
filter_frame For filters that do not use the this method is called when a frame is pushed to the filter s input It can be called at any time except in a reentrant way If the input frame is enough to produce then the filter should push the output frames on the output link immediately As an exception to the previous rule if the input frame is enough to produce several output frames then the filter needs output only at least one per link The additional frames can be left buffered in the filter
Definition: filter_design.txt:228
H264_NAL_IDR_SLICE
@ H264_NAL_IDR_SLICE
Definition: h264.h:39
AVBSFContext
The bitstream filter state.
Definition: bsf.h:68
CodedBitstreamUnit
Coded bitstream unit structure.
Definition: cbs.h:70
h264_redundant_pps_fixup_slice
static int h264_redundant_pps_fixup_slice(H264RedundantPPSContext *ctx, H264RawSliceHeader *slice)
Definition: h264_redundant_pps.c:64
bsf.h
cbs_bsf.h
h264_redundant_pps_update_fragment
static int h264_redundant_pps_update_fragment(AVBSFContext *bsf, AVPacket *pkt, CodedBitstreamFragment *au)
Definition: h264_redundant_pps.c:78
ff_cbs_make_unit_writable
int ff_cbs_make_unit_writable(CodedBitstreamContext *ctx, CodedBitstreamUnit *unit)
Make the content of a unit writable so that internal fields can be modified.
Definition: cbs.c:1044
CodedBitstreamFragment::units
CodedBitstreamUnit * units
Pointer to an array of units of length nb_units_allocated.
Definition: cbs.h:168
pkt
AVPacket * pkt
Definition: movenc.c:60
codec_id.h
CodedBitstreamFragment
Coded bitstream fragment structure, combining one or more units.
Definition: cbs.h:122
H264RawSliceHeader::slice_qp_delta
int8_t slice_qp_delta
Definition: cbs_h264.h:376
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AV_CODEC_ID_H264
@ AV_CODEC_ID_H264
Definition: codec_id.h:79
FFBitStreamFilter
Definition: bsf_internal.h:27
h264_redundant_pps_codec_ids
static enum AVCodecID h264_redundant_pps_codec_ids[]
Definition: h264_redundant_pps.c:115
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
CodedBitstreamH264Context
Definition: cbs_h264.h:404
FFBitStreamFilter::p
AVBitStreamFilter p
The public AVBitStreamFilter.
Definition: bsf_internal.h:31
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:366
pps
static int FUNC() pps(CodedBitstreamContext *ctx, RWContext *rw, H264RawPPS *current)
Definition: cbs_h264_syntax_template.c:404
CBSBSFType
Definition: cbs_bsf.h:31
ff_cbs_bsf_generic_close
void ff_cbs_bsf_generic_close(AVBSFContext *bsf)
Close a generic CBS BSF instance.
Definition: cbs_bsf.c:155
H264_NAL_SLICE
@ H264_NAL_SLICE
Definition: h264.h:35
ff_h264_redundant_pps_bsf
const FFBitStreamFilter ff_h264_redundant_pps_bsf
Definition: h264_redundant_pps.c:119
H264RawSliceHeader
Definition: cbs_h264.h:310
H264RawSlice::header
H264RawSliceHeader header
Definition: cbs_h264.h:389
log.h
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
packet.h
h264_redundant_pps_fixup_pps
static int h264_redundant_pps_fixup_pps(H264RedundantPPSContext *ctx, CodedBitstreamUnit *unit)
Definition: h264_redundant_pps.c:39
AVBSFContext::priv_data
void * priv_data
Opaque filter-specific private data.
Definition: bsf.h:83
ff_cbs_bsf_generic_filter
int ff_cbs_bsf_generic_filter(AVBSFContext *bsf, AVPacket *pkt)
Filter operation for CBS BSF.
Definition: cbs_bsf.c:61
H264RedundantPPSContext::common
CBSBSFContext common
Definition: h264_redundant_pps.c:35
h264_redundant_pps_init
static int h264_redundant_pps_init(AVBSFContext *bsf)
Definition: h264_redundant_pps.c:110
AVPacket
This structure stores compressed data.
Definition: packet.h:501
h264.h
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1283
H264RawSliceHeader::pic_parameter_set_id
uint8_t pic_parameter_set_id
Definition: cbs_h264.h:316
CodedBitstreamFragment::nb_units
int nb_units
Number of units in this fragment.
Definition: cbs.h:153
H264RawSlice
Definition: cbs_h264.h:388
H264RawPPS
Definition: cbs_h264.h:171