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 #ifndef AVCODEC_CBS_BSF_H 20 #define AVCODEC_CBS_BSF_H 21 22 #include "cbs.h" 23 24 25 typedef struct CBSBSFType { 26 enum AVCodecID codec_id; 27 28 // Name of a frame fragment in this codec (e.g. "access unit", 29 // "temporal unit"). 30 const char *fragment_name; 31 32 // Name of a unit for this BSF, for use in error messages (e.g. 33 // "NAL unit", "OBU"). 34 const char *unit_name; 35 36 // Update the content of a fragment with whatever metadata changes 37 // are desired. The associated AVPacket is provided so that any side 38 // data associated with the fragment can be inspected or edited. If 39 // pkt is NULL, then an extradata header fragment is being updated. 40 int (*update_fragment)(AVBSFContext *bsf, AVPacket *pkt, 41 CodedBitstreamFragment *frag); 42 } CBSBSFType; 43 44 // Common structure for all generic CBS BSF users. An instance of this 45 // structure must be the first member of the BSF private context (to be 46 // pointed to by AVBSFContext.priv_data). 47 typedef struct CBSBSFContext { 48 const AVClass *class; 49 const CBSBSFType *type; 50 51 CodedBitstreamContext *input; 52 CodedBitstreamContext *output; 53 CodedBitstreamFragment fragment; 54 } CBSBSFContext; 55 56 /** 57 * Initialise generic CBS BSF setup. 58 * 59 * Creates the input and output CBS instances, and applies the filter to 60 * the extradata on the input codecpar if any is present. 61 * 62 * Since it calls the update_fragment() function immediately to deal with 63 * extradata, this should be called after any codec-specific setup is done 64 * (probably at the end of the AVBitStreamFilter.init function). 65 */ 66 int ff_cbs_bsf_generic_init(AVBSFContext *bsf, const CBSBSFType *type); 67 68 /** 69 * Close a generic CBS BSF instance. 70 * 71 * If no other deinitialisation is required then this function can be used 72 * directly as AVBitStreamFilter.close. 73 */ 74 void ff_cbs_bsf_generic_close(AVBSFContext *bsf); 75 76 /** 77 * Filter operation for CBS BSF. 78 * 79 * Reads the input packet into a CBS fragment, calls update_fragment() on 80 * it, then writes the result to an output packet. If the input packet 81 * has AV_PKT_DATA_NEW_EXTRADATA side-data associated with it then it does 82 * the same thing to that new extradata to form the output side-data first. 83 * 84 * If the BSF does not do anything else then this function can be used 85 * directly as AVBitStreamFilter.filter. 86 */ 87 int ff_cbs_bsf_generic_filter(AVBSFContext *bsf, AVPacket *pkt); 88 89 90 // Options for element manipulation. 91 enum { 92 // Pass this element through unchanged. 93 BSF_ELEMENT_PASS, 94 // Insert this element, replacing any existing instances of it. 95 // Associated values may be provided explicitly (as addtional options) 96 // or implicitly (either as side data or deduced from other parts of 97 // the stream). 98 BSF_ELEMENT_INSERT, 99 // Remove this element if it appears in the stream. 100 BSF_ELEMENT_REMOVE, 101 // Extract this element to side data, so that further manipulation 102 // can happen elsewhere. 103 BSF_ELEMENT_EXTRACT, 104 }; 105 106 #define BSF_ELEMENT_OPTIONS_PIR(name, help, field, opt_flags) \ 107 { name, help, OFFSET(field), AV_OPT_TYPE_INT, \ 108 { .i64 = BSF_ELEMENT_PASS }, \ 109 BSF_ELEMENT_PASS, BSF_ELEMENT_REMOVE, opt_flags, name }, \ 110 { "pass", NULL, 0, AV_OPT_TYPE_CONST, \ 111 { .i64 = BSF_ELEMENT_PASS }, .flags = opt_flags, .unit = name }, \ 112 { "insert", NULL, 0, AV_OPT_TYPE_CONST, \ 113 { .i64 = BSF_ELEMENT_INSERT }, .flags = opt_flags, .unit = name }, \ 114 { "remove", NULL, 0, AV_OPT_TYPE_CONST, \ 115 { .i64 = BSF_ELEMENT_REMOVE }, .flags = opt_flags, .unit = name } 116 117 #define BSF_ELEMENT_OPTIONS_PIRE(name, help, field, opt_flags) \ 118 { name, help, OFFSET(field), AV_OPT_TYPE_INT, \ 119 { .i64 = BSF_ELEMENT_PASS }, \ 120 BSF_ELEMENT_PASS, BSF_ELEMENT_EXTRACT, opt_flags, name }, \ 121 { "pass", NULL, 0, AV_OPT_TYPE_CONST, \ 122 { .i64 = BSF_ELEMENT_PASS }, .flags = opt_flags, .unit = name }, \ 123 { "insert", NULL, 0, AV_OPT_TYPE_CONST, \ 124 { .i64 = BSF_ELEMENT_INSERT }, .flags = opt_flags, .unit = name }, \ 125 { "remove", NULL, 0, AV_OPT_TYPE_CONST, \ 126 { .i64 = BSF_ELEMENT_REMOVE }, .flags = opt_flags, .unit = name }, \ 127 { "extract", NULL, 0, AV_OPT_TYPE_CONST, \ 128 { .i64 = BSF_ELEMENT_EXTRACT }, .flags = opt_flags, .unit = name } \ 129 130 131 #endif /* AVCODEC_CBS_BSF_H */ 132