modules/mux/mpeg/repack.c

   1 /*****************************************************************************
   2  * repack.c: Codec specific formatting for AnnexB multiplexers
   3  *****************************************************************************
   4  * Copyright (C) 2021 VideoLabs, VLC authors and VideoLAN
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 #include <vlc_common.h>
  25 #include <vlc_block.h>
  26
  27 #include "repack.h"
  28 #include "../../packetizer/hevc_nal.h"
  29 #include "../../packetizer/h264_nal.h"
  30 #include "../../packetizer/hxxx_nal.h"
  31
  32 #include <assert.h>
  33
  34 static void AnnexBInject(block_t **pp_pes,
  35                    const uint8_t *p_extra, size_t i_extra,
  36                    const uint8_t *p_au, size_t i_au)
  37 {
  38     if(!i_extra && !i_au)
  39         return;
  40
  41     *pp_pes = block_Realloc(*pp_pes,
  42                             i_extra + i_au,
  43                             (*pp_pes)->i_buffer);
  44     if(!*pp_pes)
  45         return;
  46     if(i_au)
  47         memcpy(&(*pp_pes)->p_buffer[0], p_au, i_au);
  48     if(i_extra)
  49         memcpy(&(*pp_pes)->p_buffer[i_au], p_extra, i_extra);
  50 }
  51
  52
  53 static void PES_RepackHEVC(block_t **pp_pes,
  54                                     const uint8_t *p_extra, size_t i_extra)
  55 {
  56     size_t i_au = 6;
  57     size_t i_aucurrent = 0;
  58     const uint8_t audata[] = { 0x00, 0x00, 0x00, 0x01, 0x46, 0x01 };
  59     hxxx_iterator_ctx_t ctx;
  60     hxxx_iterator_init(&ctx, (*pp_pes)->p_buffer, (*pp_pes)->i_buffer, 0);
  61     const uint8_t *p_nal; size_t i_nal;
  62     while(hxxx_annexb_iterate_next(&ctx, &p_nal, &i_nal))
  63     {
  64         if(i_nal < 2)
  65             return;
  66         uint8_t type = hevc_getNALType(p_nal);
  67         if(type < HEVC_NAL_VPS)
  68             break;
  69         switch(type)
  70         {
  71             case HEVC_NAL_AUD:
  72                 i_au = 0;
  73                 i_aucurrent = 2 + (p_nal - (*pp_pes)->p_buffer);
  74                 break;
  75             case HEVC_NAL_VPS:
  76             case HEVC_NAL_PPS:
  77             case HEVC_NAL_SPS:
  78                 i_extra = 0;
  79                 break;
  80             default:
  81                 break;
  82         }
  83     }
  84
  85     if(i_extra && i_aucurrent) /* strip existing AU for now */
  86     {
  87         (*pp_pes)->p_buffer += i_aucurrent;
  88         (*pp_pes)->i_buffer -= i_aucurrent;
  89         i_au = 6;
  90     }
  91
  92     AnnexBInject(pp_pes, p_extra, i_extra, audata, i_au);
  93 }
  94
  95 static void PES_RepackH264(block_t **pp_pes,
  96                                     const uint8_t *p_extra, size_t i_extra)
  97 {
  98     size_t i_au = 6;
  99     size_t i_aucurrent = 0;
 100     const uint8_t audata[] = { 0x00, 0x00, 0x00, 0x01, 0x09, 0xf0 };
 101     hxxx_iterator_ctx_t ctx;
 102     hxxx_iterator_init(&ctx, (*pp_pes)->p_buffer, (*pp_pes)->i_buffer, 0);
 103     const uint8_t *p_nal; size_t i_nal;
 104     while(hxxx_annexb_iterate_next(&ctx, &p_nal, &i_nal))
 105     {
 106         if(i_nal < 2)
 107             return;
 108         uint8_t type = p_nal[0]&0x1f;
 109         if(type < H264_NAL_SEI)
 110             break;
 111         switch(type)
 112         {
 113             case H264_NAL_AU_DELIMITER:
 114                 i_au = 0;
 115                 i_aucurrent = 2 + (p_nal - (*pp_pes)->p_buffer);
 116                 break;
 117             case H264_NAL_SPS:
 118             case H264_NAL_PPS:
 119                 i_extra = 0;
 120                 break;
 121             default:
 122                 break;
 123         }
 124     }
 125
 126     if(i_extra && i_aucurrent) /* strip existing AU for now */
 127     {
 128         (*pp_pes)->p_buffer += i_aucurrent;
 129         (*pp_pes)->i_buffer -= i_aucurrent;
 130         i_au = 6;
 131     }
 132
 133     AnnexBInject(pp_pes, p_extra, i_extra, audata, i_au);
 134 }
 135
 136 static void PES_RepackMP4V(block_t **pp_pes,
 137                            const uint8_t *p_extra, size_t i_extra)
 138 {
 139     hxxx_iterator_ctx_t ctx;
 140     hxxx_iterator_init(&ctx, (*pp_pes)->p_buffer, (*pp_pes)->i_buffer, 0);
 141     const uint8_t *p_nal; size_t i_nal;
 142     while(hxxx_annexb_iterate_next(&ctx, &p_nal, &i_nal))
 143     {
 144         if(i_nal < 2)
 145             return;
 146         if(p_nal[0] >= 0x30) /* > VOLS */
 147             break;
 148         if(p_nal[0] >= 0x20 && p_nal[0] == p_extra[3]) /* same VOL */
 149             i_extra = 0;
 150     }
 151
 152     AnnexBInject(pp_pes, p_extra, i_extra, NULL, 0);
 153 }
 154
 155 block_t * PES_Repack(vlc_fourcc_t i_codec,
 156                      const uint8_t *p_extra, size_t i_extra,
 157                      block_t **pp_pes)
 158 {
 159     /* safety check for annexb extra */
 160     if(i_extra < 4 ||
 161        (memcmp(p_extra, annexb_startcode4, 4) &&
 162         memcmp(&p_extra[1], annexb_startcode3, 3)))
 163         i_extra = 0;
 164
 165     switch(i_codec)
 166     {
 167         case VLC_CODEC_HEVC:
 168             PES_RepackHEVC(pp_pes, p_extra, i_extra);
 169             break;
 170         case VLC_CODEC_H264:
 171             PES_RepackH264(pp_pes, p_extra, i_extra);
 172             break;
 173         case VLC_CODEC_MP4V:
 174             PES_RepackMP4V(pp_pes, p_extra, i_extra);
 175             break;
 176         default:
 177             break;
 178     }
 179     return *pp_pes;
 180 }