2 * This file is part of FFmpeg.
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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.
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11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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
21 #include "libavutil/log.h"
24 #include "bsf_internal.h"
32 #define NEW_GLOBAL_PIC_INIT_QP 26
34 typedef struct H264RedundantPPSContext {
36 } H264RedundantPPSContext;
39 static int h264_redundant_pps_fixup_pps(H264RedundantPPSContext *ctx,
40 CodedBitstreamUnit *unit)
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);
53 // Overwrite pic_init_qp with the global value.
54 pps->pic_init_qp_minus26 = NEW_GLOBAL_PIC_INIT_QP - 26;
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;
64 static int h264_redundant_pps_fixup_slice(H264RedundantPPSContext *ctx,
65 H264RawSliceHeader *slice)
67 const CodedBitstreamH264Context *const in = ctx->common.input->priv_data;
68 const H264RawPPS *const pps = in->pps[slice->pic_parameter_set_id];
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);
78 static int h264_redundant_pps_update_fragment(AVBSFContext *bsf,
80 CodedBitstreamFragment *au)
82 H264RedundantPPSContext *ctx = bsf->priv_data;
85 for (i = 0; i < au->nb_units; i++) {
86 CodedBitstreamUnit *nal = &au->units[i];
88 if (nal->type == H264_NAL_PPS) {
89 err = h264_redundant_pps_fixup_pps(ctx, nal);
93 if (nal->type == H264_NAL_SLICE ||
94 nal->type == H264_NAL_IDR_SLICE) {
95 H264RawSlice *slice = nal->content;
96 h264_redundant_pps_fixup_slice(ctx, &slice->header);
103 static const CBSBSFType h264_redundant_pps_type = {
104 .codec_id = AV_CODEC_ID_H264,
105 .fragment_name = "access unit",
106 .unit_name = "NAL unit",
107 .update_fragment = &h264_redundant_pps_update_fragment,
110 static int h264_redundant_pps_init(AVBSFContext *bsf)
112 return ff_cbs_bsf_generic_init(bsf, &h264_redundant_pps_type);
115 static const enum AVCodecID h264_redundant_pps_codec_ids[] = {
116 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
119 const FFBitStreamFilter ff_h264_redundant_pps_bsf = {
120 .p.name = "h264_redundant_pps",
121 .p.codec_ids = h264_redundant_pps_codec_ids,
122 .priv_data_size = sizeof(H264RedundantPPSContext),
123 .init = &h264_redundant_pps_init,
124 .close = &ff_cbs_bsf_generic_close,
125 .filter = &ff_cbs_bsf_generic_filter,