FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/h264_redundant_pps_bsf.c
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 0 41 0.0%
Branches: 0 16 0.0%

Line Branch Exec Source
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
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include <string.h>
20
21 #include "libavutil/common.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 "h264.h"
29
30
31 typedef struct H264RedundantPPSContext {
32 CBSBSFContext common;
33
34 int global_pic_init_qp;
35 int current_pic_init_qp;
36 int extradata_pic_init_qp;
37 } H264RedundantPPSContext;
38
39
40 static int h264_redundant_pps_fixup_pps(H264RedundantPPSContext *ctx,
41 CodedBitstreamUnit *unit)
42 {
43 H264RawPPS *pps;
44 int err;
45
46 // The changes we are about to perform affect the parsing process,
47 // so we must make sure that the PPS is writable, otherwise the
48 // parsing of future slices will be incorrect and even raise errors.
49 err = ff_cbs_make_unit_writable(ctx->common.input, unit);
50 if (err < 0)
51 return err;
52 pps = unit->content;
53
54 // Record the current value of pic_init_qp in order to fix up
55 // following slices, then overwrite with the global value.
56 ctx->current_pic_init_qp = pps->pic_init_qp_minus26 + 26;
57 pps->pic_init_qp_minus26 = ctx->global_pic_init_qp - 26;
58
59 // Some PPSs have this set, so it must be set in all of them.
60 // (Slices which do not use such a PPS on input will still have
61 // *_weight_l*flag as zero and therefore write equivalently.)
62 pps->weighted_pred_flag = 1;
63
64 return 0;
65 }
66
67 static int h264_redundant_pps_fixup_slice(H264RedundantPPSContext *ctx,
68 H264RawSliceHeader *slice)
69 {
70 int qp;
71
72 qp = ctx->current_pic_init_qp + slice->slice_qp_delta;
73 slice->slice_qp_delta = qp - ctx->global_pic_init_qp;
74
75 return 0;
76 }
77
78 static int h264_redundant_pps_update_fragment(AVBSFContext *bsf,
79 AVPacket *pkt,
80 CodedBitstreamFragment *au)
81 {
82 H264RedundantPPSContext *ctx = bsf->priv_data;
83 int au_has_sps;
84 int err, i;
85
86 au_has_sps = 0;
87 for (i = 0; i < au->nb_units; i++) {
88 CodedBitstreamUnit *nal = &au->units[i];
89
90 if (nal->type == H264_NAL_SPS)
91 au_has_sps = 1;
92 if (nal->type == H264_NAL_PPS) {
93 err = h264_redundant_pps_fixup_pps(ctx, nal);
94 if (err < 0)
95 return err;
96 if (!au_has_sps) {
97 av_log(bsf, AV_LOG_VERBOSE, "Deleting redundant PPS "
98 "at %"PRId64".\n", pkt->pts);
99 ff_cbs_delete_unit(au, i);
100 i--;
101 continue;
102 }
103 }
104 if (nal->type == H264_NAL_SLICE ||
105 nal->type == H264_NAL_IDR_SLICE) {
106 H264RawSlice *slice = nal->content;
107 h264_redundant_pps_fixup_slice(ctx, &slice->header);
108 }
109 }
110
111 return 0;
112 }
113
114 static void h264_redundant_pps_flush(AVBSFContext *bsf)
115 {
116 H264RedundantPPSContext *ctx = bsf->priv_data;
117 ctx->current_pic_init_qp = ctx->extradata_pic_init_qp;
118 }
119
120 static const CBSBSFType h264_redundant_pps_type = {
121 .codec_id = AV_CODEC_ID_H264,
122 .fragment_name = "access unit",
123 .unit_name = "NAL unit",
124 .update_fragment = &h264_redundant_pps_update_fragment,
125 };
126
127 static int h264_redundant_pps_init(AVBSFContext *bsf)
128 {
129 H264RedundantPPSContext *ctx = bsf->priv_data;
130
131 ctx->global_pic_init_qp = 26;
132
133 return ff_cbs_bsf_generic_init(bsf, &h264_redundant_pps_type);
134 }
135
136 static const enum AVCodecID h264_redundant_pps_codec_ids[] = {
137 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
138 };
139
140 const AVBitStreamFilter ff_h264_redundant_pps_bsf = {
141 .name = "h264_redundant_pps",
142 .priv_data_size = sizeof(H264RedundantPPSContext),
143 .init = &h264_redundant_pps_init,
144 .flush = &h264_redundant_pps_flush,
145 .close = &ff_cbs_bsf_generic_close,
146 .filter = &ff_cbs_bsf_generic_filter,
147 .codec_ids = h264_redundant_pps_codec_ids,
148 };
149