git.sesse.net Git - vlc/blob - modules/packetizer/h264.c

   1 /*****************************************************************************
   2  * h264.c: h264/avc video packetizer
   3  *****************************************************************************
   4  * Copyright (C) 2001, 2002 VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *          Eric Petit <titer@videolan.org>
   9  *          Gildas Bazin <gbazin@netcourrier.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #include <stdlib.h>                                      /* malloc(), free() */
  30
  31 #include <vlc/vlc.h>
  32 #include <vlc/decoder.h>
  33 #include <vlc/sout.h>
  34
  35 #include "vlc_block_helper.h"
  36 #include "vlc_bits.h"
  37
  38 /*****************************************************************************
  39  * Module descriptor
  40  *****************************************************************************/
  41 static int  Open ( vlc_object_t * );
  42 static void Close( vlc_object_t * );
  43
  44 vlc_module_begin();
  45     set_description( _("H264 video packetizer") );
  46     set_capability( "packetizer", 50 );
  47     set_callbacks( Open, Close );
  48 vlc_module_end();
  49
  50
  51 /****************************************************************************
  52  * Local prototypes
  53  ****************************************************************************/
  54 static block_t *Packetize( decoder_t *, block_t ** );
  55
  56 struct decoder_sys_t
  57 {
  58     block_bytestream_t bytestream;
  59
  60     int     i_state;
  61     int     i_offset;
  62     uint8_t startcode[4];
  63
  64     vlc_bool_t b_slice;
  65     block_t    *p_frame;
  66
  67     int64_t      i_dts;
  68     int64_t      i_pts;
  69     unsigned int i_flags;
  70
  71     vlc_bool_t   b_sps;
  72 };
  73
  74 enum
  75 {
  76     STATE_NOSYNC,
  77     STATE_NEXT_SYNC,
  78 };
  79
  80 enum nal_unit_type_e
  81 {
  82     NAL_UNKNOWN = 0,
  83     NAL_SLICE   = 1,
  84     NAL_SLICE_DPA   = 2,
  85     NAL_SLICE_DPB   = 3,
  86     NAL_SLICE_DPC   = 4,
  87     NAL_SLICE_IDR   = 5,    /* ref_idc != 0 */
  88     NAL_SEI         = 6,    /* ref_idc == 0 */
  89     NAL_SPS         = 7,
  90     NAL_PPS         = 8
  91     /* ref_idc == 0 for 6,9,10,11,12 */
  92 };
  93
  94 enum nal_priority_e
  95 {
  96     NAL_PRIORITY_DISPOSABLE = 0,
  97     NAL_PRIORITY_LOW        = 1,
  98     NAL_PRIORITY_HIGH       = 2,
  99     NAL_PRIORITY_HIGHEST    = 3,
 100 };
 101
 102 static block_t *ParseNALBlock( decoder_t *, block_t * );
 103
 104 /*****************************************************************************
 105  * Open: probe the packetizer and return score
 106  *****************************************************************************/
 107 static int Open( vlc_object_t *p_this )
 108 {
 109     decoder_t     *p_dec = (decoder_t*)p_this;
 110     decoder_sys_t *p_sys;
 111
 112     if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
 113         p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') )
 114     {
 115         return VLC_EGENERIC;
 116     }
 117
 118     /* Allocate the memory needed to store the decoder's structure */
 119     if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
 120     {
 121         msg_Err( p_dec, "out of memory" );
 122         return VLC_EGENERIC;
 123     }
 124     p_sys->i_state = STATE_NOSYNC;
 125     p_sys->i_offset = 0;
 126     p_sys->startcode[0] = 0;
 127     p_sys->startcode[1] = 0;
 128     p_sys->startcode[2] = 0;
 129     p_sys->startcode[3] = 1;
 130     p_sys->bytestream = block_BytestreamInit( p_dec );
 131     p_sys->b_slice = VLC_FALSE;
 132     p_sys->p_frame = NULL;
 133     p_sys->i_dts   = 0;
 134     p_sys->i_pts   = 0;
 135     p_sys->i_flags = 0;
 136     p_sys->b_sps   = VLC_FALSE;
 137
 138     /* Setup properties */
 139     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 140     p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
 141
 142 #if 0
 143     if( p_dec->fmt_in.i_extra )
 144     {
 145         /* We have a vol */
 146         p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
 147         p_dec->fmt_out.p_extra = malloc( p_dec->fmt_in.i_extra );
 148         memcpy( p_dec->fmt_out.p_extra, p_dec->fmt_in.p_extra,
 149                 p_dec->fmt_in.i_extra );
 150
 151         msg_Dbg( p_dec, "opening with vol size:%d", p_dec->fmt_in.i_extra );
 152         m4v_VOLParse( &p_dec->fmt_out,
 153                       p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
 154     }
 155     else
 156     {
 157         /* No vol, we'll have to look for one later on */
 158         p_dec->fmt_out.i_extra = 0;
 159         p_dec->fmt_out.p_extra = 0;
 160     }
 161 #endif
 162
 163     /* Set callback */
 164     p_dec->pf_packetize = Packetize;
 165
 166     return VLC_SUCCESS;
 167 }
 168
 169 /*****************************************************************************
 170  * Close: clean up the packetizer
 171  *****************************************************************************/
 172 static void Close( vlc_object_t *p_this )
 173 {
 174     decoder_t *p_dec = (decoder_t*)p_this;
 175     decoder_sys_t *p_sys = p_dec->p_sys;
 176
 177     block_BytestreamRelease( &p_sys->bytestream );
 178     free( p_sys );
 179 }
 180
 181 /****************************************************************************
 182  * Packetize: the whole thing
 183  ****************************************************************************/
 184 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 185 {
 186     decoder_sys_t *p_sys = p_dec->p_sys;
 187     block_t       *p_pic;
 188
 189     if( !pp_block || !*pp_block ) return NULL;
 190
 191     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 192
 193     for( ;; )
 194     {
 195         switch( p_sys->i_state )
 196         {
 197             case STATE_NOSYNC:
 198                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 199                         &p_sys->i_offset, p_sys->startcode, 4 ) == VLC_SUCCESS )
 200                 {
 201                     p_sys->i_state = STATE_NEXT_SYNC;
 202                 }
 203
 204                 if( p_sys->i_offset )
 205                 {
 206                     block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 207                     p_sys->i_offset = 0;
 208                     block_BytestreamFlush( &p_sys->bytestream );
 209                 }
 210
 211                 if( p_sys->i_state != STATE_NEXT_SYNC )
 212                 {
 213                     /* Need more data */
 214                     return NULL;
 215                 }
 216
 217                 p_sys->i_offset = 1; /* To find next startcode */
 218
 219             case STATE_NEXT_SYNC:
 220                 /* Find the next startcode */
 221                 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
 222                         &p_sys->i_offset, p_sys->startcode, 4 ) != VLC_SUCCESS )
 223                 {
 224                     /* Need more data */
 225                     return NULL;
 226                 }
 227
 228                 /* Get the new fragment and set the pts/dts */
 229                 p_pic = block_New( p_dec, p_sys->i_offset );
 230                 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 231                 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 232
 233                 block_GetBytes( &p_sys->bytestream, p_pic->p_buffer,
 234                                 p_pic->i_buffer );
 235
 236                 p_sys->i_offset = 0;
 237
 238                 /* Parse the NAL */
 239                 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
 240                 {
 241                     p_sys->i_state = STATE_NOSYNC;
 242                     break;
 243                 }
 244
 245                 /* So p_block doesn't get re-added several times */
 246                 *pp_block = block_BytestreamPop( &p_sys->bytestream );
 247
 248                 p_sys->i_state = STATE_NOSYNC;
 249
 250                 return p_pic;
 251         }
 252     }
 253 }
 254
 255 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret, uint8_t *src, int i_src )
 256 {
 257     uint8_t *end = &src[i_src];
 258     uint8_t *dst = malloc( i_src );
 259
 260     *pp_ret = dst;
 261
 262     while( src < end )
 263     {
 264         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00  && src[2] == 0x03 )
 265         {
 266             *dst++ = 0x00;
 267             *dst++ = 0x00;
 268
 269             src += 3;
 270             continue;
 271         }
 272         *dst++ = *src++;
 273     }
 274
 275     *pi_ret = dst - *pp_ret;
 276 }
 277
 278 static inline int bs_read_ue( bs_t *s )
 279 {
 280     int i = 0;
 281
 282     while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
 283     {
 284         i++;
 285     }
 286     return( ( 1 << i) - 1 + bs_read( s, i ) );
 287 }
 288 static inline int bs_read_se( bs_t *s )
 289 {
 290     int val = bs_read_ue( s );
 291
 292     return val&0x01 ? (val+1)/2 : -(val/2);
 293 }
 294
 295
 296 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
 297 {
 298     decoder_sys_t *p_sys = p_dec->p_sys;
 299     block_t *p_pic = NULL;
 300
 301     const int i_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
 302     const int i_nal_type= p_frag->p_buffer[4]&0x1f;
 303
 304     if( p_sys->b_slice &&
 305         ( i_nal_type == NAL_SLICE || i_nal_type == NAL_SLICE_IDR ||
 306           i_nal_type == NAL_SLICE_DPC || i_nal_type == NAL_SPS || i_nal_type == NAL_PPS ) )
 307     {
 308         if( p_sys->b_sps )
 309         {
 310             p_pic = block_ChainGather( p_sys->p_frame );
 311             p_pic->i_dts = p_sys->i_dts;
 312             p_pic->i_pts = p_sys->i_pts;
 313             p_pic->i_length = 0;    /* FIXME */
 314             p_pic->i_flags = p_sys->i_flags;
 315         }
 316         else
 317         {
 318             block_ChainRelease( p_sys->p_frame );
 319         }
 320
 321         /* reset context */
 322         p_sys->p_frame = NULL;
 323         p_sys->b_slice = VLC_FALSE;
 324         //p_sys->i_dts += 40000;
 325     }
 326
 327     if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
 328     {
 329         uint8_t *dec;
 330         int     i_dec;
 331         bs_t s;
 332
 333         p_sys->b_slice = VLC_TRUE;
 334         p_sys->i_dts   = p_frag->i_dts;
 335         p_sys->i_pts   = p_frag->i_pts;
 336
 337         /* do not convert the whole frame */
 338         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], __MIN( p_frag->i_buffer - 5, 60 ) );
 339         bs_init( &s, dec, i_dec );
 340
 341         /* i_first_mb */
 342         bs_read_ue( &s );
 343         /* picture type */
 344         switch( bs_read_ue( &s ) )
 345         {
 346             case 0: case 5:
 347                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 348                 break;
 349             case 1: case 6:
 350                 p_sys->i_flags =BLOCK_FLAG_TYPE_B;
 351                 break;
 352             case 2: case 7:
 353                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 354                 break;
 355             case 3: case 8: /* SP */
 356                 p_sys->i_flags = BLOCK_FLAG_TYPE_P;
 357                 break;
 358             case 4: case 9:
 359                 p_sys->i_flags = BLOCK_FLAG_TYPE_I;
 360                 break;
 361         }
 362
 363         free( dec );
 364     }
 365     else if( i_nal_type == NAL_SPS )
 366     {
 367         uint8_t *dec;
 368         int     i_dec;
 369         bs_t s;
 370         int i_tmp;
 371
 372         p_sys->b_sps = VLC_TRUE;
 373
 374         nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 375
 376         bs_init( &s, dec, i_dec );
 377         /* Skip profile(8), constraint_set012, reserver(5), level(8) */
 378         bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
 379         /* sps id */
 380         bs_read_ue( &s );
 381         /* Skip i_log2_max_frame_num */
 382         bs_read_ue( &s );
 383         /* Read poc_type */
 384         i_tmp = bs_read_ue( &s );
 385         if( i_tmp == 0 )
 386         {
 387             /* skip i_log2_max_poc_lsb */
 388             bs_read_ue( &s );
 389         }
 390         else if( i_tmp == 1 )
 391         {
 392             int i_cycle;
 393             /* skip b_delta_pic_order_always_zero */
 394             bs_skip( &s, 1 );
 395             /* skip i_offset_for_non_ref_pic */
 396             bs_read_se( &s );
 397             /* skip i_offset_for_top_to_bottom_field */
 398             bs_read_se( &s );
 399             /* read i_num_ref_frames_in_poc_cycle */
 400             i_cycle = bs_read_ue( &s );
 401             if( i_cycle > 256 ) i_cycle = 256;
 402             while( i_cycle > 0 )
 403             {
 404                 /* skip i_offset_for_ref_frame */
 405                 bs_read_se(&s );
 406             }
 407         }
 408         /* i_num_ref_frames */
 409         bs_read_ue( &s );
 410         /* b_gaps_in_frame_num_value_allowed */
 411         bs_skip( &s, 1 );
 412
 413         /* Read size */
 414         p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
 415         p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
 416
 417         /* b_frame_mbs_only */
 418         i_tmp = bs_read( &s, 1 );
 419         if( i_tmp == 0 )
 420         {
 421             bs_skip( &s, 1 );
 422         }
 423         /* b_direct8x8_inference */
 424         bs_skip( &s, 1 );
 425
 426         /* crop ? */
 427         i_tmp = bs_read( &s, 1 );
 428         if( i_tmp )
 429         {
 430             /* left */
 431             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 432             /* right */
 433             p_dec->fmt_out.video.i_width -= 2 * bs_read_ue( &s );
 434             /* top */
 435             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 436             /* bottom */
 437             p_dec->fmt_out.video.i_height -= 2 * bs_read_ue( &s );
 438         }
 439
 440         /* vui */
 441         i_tmp = bs_read( &s, 1 );
 442         if( i_tmp )
 443         {
 444             /* read the aspect ratio part if any FIXME check it */
 445             i_tmp = bs_read( &s, 1 );
 446             if( i_tmp )
 447             {
 448                 static const struct { int w, h; } sar[14] =
 449                 {
 450                     { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
 451                     { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
 452                     { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
 453                     { 64, 33 }, { 160,99 },
 454                 };
 455                 int i_sar = bs_read( &s, 8 );
 456                 int w, h;
 457
 458                 if( i_sar < 14 )
 459                 {
 460                     w = sar[i_sar].w;
 461                     h = sar[i_sar].h;
 462                 }
 463                 else
 464                 {
 465                     w = bs_read( &s, 16 );
 466                     h = bs_read( &s, 16 );
 467                 }
 468                 p_dec->fmt_out.video.i_aspect =
 469                     VOUT_ASPECT_FACTOR *
 470                     w / h *
 471                     p_dec->fmt_out.video.i_width / p_dec->fmt_out.video.i_height;
 472             }
 473         }
 474
 475         free( dec );
 476     }
 477     else if( i_nal_type == NAL_PPS )
 478     {
 479         bs_t s;
 480         bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
 481
 482         /* TODO */
 483     }
 484
 485
 486     /* Append the block */
 487     block_ChainAppend( &p_sys->p_frame, p_frag );
 488
 489     return p_pic;
 490 }
 491