modules/codec/h264_nal.c

   1 /*****************************************************************************
   2  * Copyright © 2010-2014 VideoLAN
   3  *
   4  * Authors: Jean-Baptiste Kempf <jb@videolan.org>
   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
  21 #include "h264_nal.h"
  22
  23 #include <limits.h>
  24
  25 int convert_sps_pps( decoder_t *p_dec, const uint8_t *p_buf,
  26                      uint32_t i_buf_size, uint8_t *p_out_buf,
  27                      uint32_t i_out_buf_size, uint32_t *p_sps_pps_size,
  28                      uint32_t *p_nal_size)
  29 {
  30     int i_profile;
  31     uint32_t i_data_size = i_buf_size, i_nal_size, i_sps_pps_size = 0;
  32     unsigned int i_loop_end;
  33
  34     /* */
  35     if( i_data_size < 7 )
  36     {
  37         msg_Err( p_dec, "Input Metadata too small" );
  38         return VLC_ENOMEM;
  39     }
  40
  41     /* Read infos in first 6 bytes */
  42     i_profile = (p_buf[1] << 16) | (p_buf[2] << 8) | p_buf[3];
  43     if (p_nal_size)
  44         *p_nal_size  = (p_buf[4] & 0x03) + 1;
  45     p_buf       += 5;
  46     i_data_size -= 5;
  47
  48     for ( unsigned int j = 0; j < 2; j++ )
  49     {
  50         /* First time is SPS, Second is PPS */
  51         if( i_data_size < 1 )
  52         {
  53             msg_Err( p_dec, "PPS too small after processing SPS/PPS %u",
  54                     i_data_size );
  55             return VLC_ENOMEM;
  56         }
  57         i_loop_end = p_buf[0] & (j == 0 ? 0x1f : 0xff);
  58         p_buf++; i_data_size--;
  59
  60         for ( unsigned int i = 0; i < i_loop_end; i++)
  61         {
  62             if( i_data_size < 2 )
  63             {
  64                 msg_Err( p_dec, "SPS is too small %u", i_data_size );
  65                 return VLC_ENOMEM;
  66             }
  67
  68             i_nal_size = (p_buf[0] << 8) | p_buf[1];
  69             p_buf += 2;
  70             i_data_size -= 2;
  71
  72             if( i_data_size < i_nal_size )
  73             {
  74                 msg_Err( p_dec, "SPS size does not match NAL specified size %u",
  75                         i_data_size );
  76                 return VLC_ENOMEM;
  77             }
  78             if( i_sps_pps_size + 4 + i_nal_size > i_out_buf_size )
  79             {
  80                 msg_Err( p_dec, "Output SPS/PPS buffer too small" );
  81                 return VLC_ENOMEM;
  82             }
  83
  84             p_out_buf[i_sps_pps_size++] = 0;
  85             p_out_buf[i_sps_pps_size++] = 0;
  86             p_out_buf[i_sps_pps_size++] = 0;
  87             p_out_buf[i_sps_pps_size++] = 1;
  88
  89             memcpy( p_out_buf + i_sps_pps_size, p_buf, i_nal_size );
  90             i_sps_pps_size += i_nal_size;
  91
  92             p_buf += i_nal_size;
  93             i_data_size -= i_nal_size;
  94         }
  95     }
  96
  97     *p_sps_pps_size = i_sps_pps_size;
  98
  99     return VLC_SUCCESS;
 100 }
 101
 102 void convert_h264_to_annexb( uint8_t *p_buf, uint32_t i_len,
 103                              size_t i_nal_size,
 104                              struct H264ConvertState *state )
 105 {
 106     if( i_nal_size < 3 || i_nal_size > 4 )
 107         return;
 108
 109     /* This only works for NAL sizes 3-4 */
 110     while( i_len > 0 )
 111     {
 112         if( state->nal_pos < i_nal_size ) {
 113             unsigned int i;
 114             for( i = 0; state->nal_pos < i_nal_size && i < i_len; i++, state->nal_pos++ ) {
 115                 state->nal_len = (state->nal_len << 8) | p_buf[i];
 116                 p_buf[i] = 0;
 117             }
 118             if( state->nal_pos < i_nal_size )
 119                 return;
 120             p_buf[i - 1] = 1;
 121             p_buf += i;
 122             i_len -= i;
 123         }
 124         if( state->nal_len > INT_MAX )
 125             return;
 126         if( state->nal_len > i_len )
 127         {
 128             state->nal_len -= i_len;
 129             return;
 130         }
 131         else
 132         {
 133             p_buf += state->nal_len;
 134             i_len -= state->nal_len;
 135             state->nal_len = 0;
 136             state->nal_pos = 0;
 137         }
 138     }
 139 }
 140
 141 bool h264_get_profile_level(const es_format_t *p_fmt, size_t *p_profile,
 142                             size_t *p_level, size_t *p_nal_size)
 143 {
 144     uint8_t *p = (uint8_t*)p_fmt->p_extra;
 145     if(!p || !p_fmt->p_extra) return false;
 146
 147     /* Check the profile / level */
 148     if (p_fmt->i_original_fourcc == VLC_FOURCC('a','v','c','1') && p[0] == 1)
 149     {
 150         if (p_fmt->i_extra < 12) return false;
 151         if (p_nal_size) *p_nal_size = 1 + (p[4]&0x03);
 152         if (!(p[5]&0x1f)) return false;
 153         p += 8;
 154     }
 155     else
 156     {
 157         if (p_fmt->i_extra < 8) return false;
 158         if (!p[0] && !p[1] && !p[2] && p[3] == 1) p += 4;
 159         else if (!p[0] && !p[1] && p[2] == 1) p += 3;
 160         else return false;
 161     }
 162
 163     if ( ((*p++)&0x1f) != 7) return false;
 164
 165     /* Get profile/level out of first SPS */
 166     if (p_profile) *p_profile = p[0];
 167     if (p_level) *p_level = p[2];
 168     return true;
 169 }