| /* |
| * 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 <inttypes.h> |
| |
| #include "libavutil/log.h" |
| |
| #include "bsf.h" |
| #include "bsf_internal.h" |
| #include "cbs.h" |
| #include "cbs_bsf.h" |
| #include "cbs_h264.h" |
| #include "codec_id.h" |
| #include "h264.h" |
| #include "packet.h" |
| |
| #define NEW_GLOBAL_PIC_INIT_QP 26 |
| |
| typedef struct H264RedundantPPSContext { |
| CBSBSFContext common; |
| } H264RedundantPPSContext; |
| |
| |
| static int h264_redundant_pps_fixup_pps(H264RedundantPPSContext *ctx, |
| CodedBitstreamUnit *unit) |
| { |
| H264RawPPS *pps; |
| int err; |
| |
| // The changes we are about to perform affect the parsing process, |
| // so we must make sure that the PPS is writable, otherwise the |
| // parsing of future slices will be incorrect and even raise errors. |
| err = ff_cbs_make_unit_writable(ctx->common.input, unit); |
| if (err < 0) |
| return err; |
| pps = unit->content; |
| |
| // Overwrite pic_init_qp with the global value. |
| pps->pic_init_qp_minus26 = NEW_GLOBAL_PIC_INIT_QP - 26; |
| |
| // Some PPSs have this set, so it must be set in all of them. |
| // (Slices which do not use such a PPS on input will still have |
| // *_weight_l*flag as zero and therefore write equivalently.) |
| pps->weighted_pred_flag = 1; |
| |
| return 0; |
| } |
| |
| static int h264_redundant_pps_fixup_slice(H264RedundantPPSContext *ctx, |
| H264RawSliceHeader *slice) |
| { |
| const CodedBitstreamH264Context *const in = ctx->common.input->priv_data; |
| const H264RawPPS *const pps = in->pps[slice->pic_parameter_set_id]; |
| |
| // We modified the PPS's qp value, now offset this by applying |
| // the negative offset to the slices. |
| slice->slice_qp_delta += pps->pic_init_qp_minus26 |
| - (NEW_GLOBAL_PIC_INIT_QP - 26); |
| |
| return 0; |
| } |
| |
| static int h264_redundant_pps_update_fragment(AVBSFContext *bsf, |
| AVPacket *pkt, |
| CodedBitstreamFragment *au) |
| { |
| H264RedundantPPSContext *ctx = bsf->priv_data; |
| int err, i; |
| |
| for (i = 0; i < au->nb_units; i++) { |
| CodedBitstreamUnit *nal = &au->units[i]; |
| |
| if (nal->type == H264_NAL_PPS) { |
| err = h264_redundant_pps_fixup_pps(ctx, nal); |
| if (err < 0) |
| return err; |
| } |
| if (nal->type == H264_NAL_SLICE || |
| nal->type == H264_NAL_IDR_SLICE) { |
| H264RawSlice *slice = nal->content; |
| h264_redundant_pps_fixup_slice(ctx, &slice->header); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static const CBSBSFType h264_redundant_pps_type = { |
| .codec_id = AV_CODEC_ID_H264, |
| .fragment_name = "access unit", |
| .unit_name = "NAL unit", |
| .update_fragment = &h264_redundant_pps_update_fragment, |
| }; |
| |
| static int h264_redundant_pps_init(AVBSFContext *bsf) |
| { |
| return ff_cbs_bsf_generic_init(bsf, &h264_redundant_pps_type); |
| } |
| |
| static const enum AVCodecID h264_redundant_pps_codec_ids[] = { |
| AV_CODEC_ID_H264, AV_CODEC_ID_NONE, |
| }; |
| |
| const FFBitStreamFilter ff_h264_redundant_pps_bsf = { |
| .p.name = "h264_redundant_pps", |
| .p.codec_ids = h264_redundant_pps_codec_ids, |
| .priv_data_size = sizeof(H264RedundantPPSContext), |
| .init = &h264_redundant_pps_init, |
| .close = &ff_cbs_bsf_generic_close, |
| .filter = &ff_cbs_bsf_generic_filter, |
| }; |