1 /*****************************************************************************
2 * h264.c: h264/avc video packetizer
3 *****************************************************************************
4 * Copyright (C) 2001, 2002, 2006 the VideoLAN team
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8 * Eric Petit <titer@videolan.org>
9 * Gildas Bazin <gbazin@videolan.org>
10 * Derk-Jan Hartman <hartman at videolan dot org>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
35 #include <vlc_common.h>
36 #include <vlc_plugin.h>
38 #include <vlc_codec.h>
39 #include <vlc_block.h>
41 #include "vlc_block_helper.h"
44 /*****************************************************************************
46 *****************************************************************************/
47 static int Open ( vlc_object_t * );
48 static void Close( vlc_object_t * );
51 set_category( CAT_SOUT );
52 set_subcategory( SUBCAT_SOUT_PACKETIZER );
53 set_description( N_("H.264 video packetizer") );
54 set_capability( "packetizer", 50 );
55 set_callbacks( Open, Close );
59 /****************************************************************************
61 ****************************************************************************/
62 static block_t *Packetize( decoder_t *, block_t ** );
63 static block_t *PacketizeAVC1( decoder_t *, block_t ** );
71 int i_pic_parameter_set_id;
75 int i_bottom_field_flag;
79 int i_pic_order_cnt_lsb;
80 int i_delta_pic_order_cnt_bottom;
82 int i_delta_pic_order_cnt0;
83 int i_delta_pic_order_cnt1;
90 block_bytestream_t bytestream;
104 int i_avcC_length_size;
108 /* Useful values of the Sequence Parameter Set */
109 int i_log2_max_frame_num;
110 int b_frame_mbs_only;
111 int i_pic_order_cnt_type;
112 int i_delta_pic_order_always_zero_flag;
113 int i_log2_max_pic_order_cnt_lsb;
115 /* Value from Picture Parameter Set */
116 int i_pic_order_present_flag;
118 /* Useful values of the Slice Header */
135 NAL_SLICE_IDR = 5, /* ref_idc != 0 */
136 NAL_SEI = 6, /* ref_idc == 0 */
140 /* ref_idc == 0 for 6,9,10,11,12 */
145 NAL_PRIORITY_DISPOSABLE = 0,
146 NAL_PRIORITY_LOW = 1,
147 NAL_PRIORITY_HIGH = 2,
148 NAL_PRIORITY_HIGHEST = 3,
151 static block_t *ParseNALBlock( decoder_t *, block_t * );
153 static block_t *CreateAnnexbNAL( decoder_t *, const uint8_t *p, int );
155 static block_t *OutputPicture( decoder_t *p_dec );
156 static void PutSPS( decoder_t *p_dec, block_t *p_frag );
157 static void PutPPS( decoder_t *p_dec, block_t *p_frag );
158 static void ParseSlice( decoder_t *p_dec, bool *pb_new_picture, slice_t *p_slice,
159 int i_nal_ref_idc, int i_nal_type, const block_t *p_frag );
162 /*****************************************************************************
163 * Open: probe the packetizer and return score
164 * When opening after demux, the packetizer is only loaded AFTER the decoder
165 * That means that what you set in fmt_out is ignored by the decoder in this special case
166 *****************************************************************************/
167 static int Open( vlc_object_t *p_this )
169 decoder_t *p_dec = (decoder_t*)p_this;
170 decoder_sys_t *p_sys;
172 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
173 p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
174 p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
175 p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
176 p_dec->fmt_in.i_codec != VLC_FOURCC( 'D', 'A', 'V', 'C') &&
177 ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
178 p_dec->fmt_in.i_extra < 7 ) )
183 /* Allocate the memory needed to store the decoder's structure */
184 if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
188 p_sys->i_state = STATE_NOSYNC;
190 p_sys->startcode[0] = 0;
191 p_sys->startcode[1] = 0;
192 p_sys->startcode[2] = 0;
193 p_sys->startcode[3] = 1;
194 p_sys->bytestream = block_BytestreamInit();
195 p_sys->b_slice = false;
196 p_sys->p_frame = NULL;
197 p_sys->b_sps = false;
198 p_sys->b_pps = false;
201 p_sys->b_header= false;
203 p_sys->slice.i_nal_type = -1;
204 p_sys->slice.i_nal_ref_idc = -1;
205 p_sys->slice.i_idr_pic_id = -1;
206 p_sys->slice.i_frame_num = -1;
207 p_sys->slice.i_frame_type = 0;
208 p_sys->slice.i_pic_parameter_set_id = -1;
209 p_sys->slice.i_field_pic_flag = 0;
210 p_sys->slice.i_bottom_field_flag = -1;
211 p_sys->slice.i_pic_order_cnt_lsb = -1;
212 p_sys->slice.i_delta_pic_order_cnt_bottom = -1;
214 /* Setup properties */
215 es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
216 p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
218 if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
220 /* This type of stream is produced by mp4 and matroska
221 * when we want to store it in another streamformat, you need to convert
222 * The fmt_in.p_extra should ALWAYS contain the avcC
223 * The fmt_out.p_extra should contain all the SPS and PPS with 4 byte startcodes */
224 uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
229 p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
233 for( i = 0; i < i_sps; i++ )
235 uint16_t i_length = GetWBE( p ); p += 2;
237 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
241 block_t *p_sps = CreateAnnexbNAL( p_dec, p, i_length );
244 ParseNALBlock( p_dec, p_sps );
249 for( i = 0; i < i_pps; i++ )
251 uint16_t i_length = GetWBE( p ); p += 2;
253 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
257 block_t *p_pps = CreateAnnexbNAL( p_dec, p, i_length );
260 ParseNALBlock( p_dec, p_pps );
263 msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
264 p_sys->i_avcC_length_size, i_sps, i_pps );
266 if( !p_sys->p_sps || p_sys->p_pps )
269 /* FIXME: FFMPEG isn't happy at all if you leave this */
270 if( p_dec->fmt_out.i_extra > 0 ) free( p_dec->fmt_out.p_extra );
271 p_dec->fmt_out.i_extra = 0;
272 p_dec->fmt_out.p_extra = NULL;
274 /* Set the new extradata */
275 p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
276 p_dec->fmt_out.p_extra = malloc( p_dec->fmt_out.i_extra );
277 if( p_dec->fmt_out.p_extra )
279 memcpy( (uint8_t*)p_dec->fmt_out.p_extra,
280 p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
281 memcpy( (uint8_t*)p_dec->fmt_out.p_extra+p_sys->p_sps->i_buffer,
282 p_sys->p_pps->p_buffer, p_sys->p_pps->i_buffer);
283 p_sys->b_header = true;
285 else p_dec->fmt_out.i_extra = 0;
288 p_dec->pf_packetize = PacketizeAVC1;
292 /* This type of stream contains data with 3 of 4 byte startcodes
293 * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
294 * The fmt_out.p_extra should be the same */
297 p_dec->pf_packetize = Packetize;
300 if( p_dec->fmt_in.i_extra > 0 )
302 block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
305 memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
306 p_dec->fmt_in.i_extra );
308 while( ( p_pic = Packetize( p_dec, &p_init ) ) )
310 /* Should not occur because we should only receive SPS/PPS */
311 block_Release( p_pic );
319 /*****************************************************************************
320 * Close: clean up the packetizer
321 *****************************************************************************/
322 static void Close( vlc_object_t *p_this )
324 decoder_t *p_dec = (decoder_t*)p_this;
325 decoder_sys_t *p_sys = p_dec->p_sys;
327 if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
328 if( p_sys->p_sps ) block_Release( p_sys->p_sps );
329 if( p_sys->p_pps ) block_Release( p_sys->p_pps );
330 block_BytestreamRelease( &p_sys->bytestream );
334 /****************************************************************************
335 * Packetize: the whole thing
336 * Search for the startcodes 3 or more bytes
337 * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
338 ****************************************************************************/
339 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
341 decoder_sys_t *p_sys = p_dec->p_sys;
344 if( !pp_block || !*pp_block )
347 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
349 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
351 p_sys->i_state = STATE_NOSYNC;
352 block_BytestreamFlush( &p_sys->bytestream );
355 block_ChainRelease( p_sys->p_frame );
356 p_sys->p_frame = NULL;
357 p_sys->slice.i_frame_type = 0;
358 p_sys->b_slice = false;
360 block_Release( *pp_block );
364 block_BytestreamPush( &p_sys->bytestream, *pp_block );
368 switch( p_sys->i_state )
371 /* Skip until 3 byte startcode 0 0 1 */
372 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
373 &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
375 p_sys->i_state = STATE_NEXT_SYNC;
378 if( p_sys->i_offset )
381 block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
383 block_BytestreamFlush( &p_sys->bytestream );
386 if( p_sys->i_state != STATE_NEXT_SYNC )
392 p_sys->i_offset = 1; /* To find next startcode */
394 case STATE_NEXT_SYNC:
395 /* Find the next 3 byte startcode 0 0 1*/
396 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
397 &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
403 /* Get the new fragment and set the pts/dts */
404 p_pic = block_New( p_dec, p_sys->i_offset +1 );
405 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
406 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
407 /* Force 4 byte startcode 0 0 0 1 */
408 p_pic->p_buffer[0] = 0;
410 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
413 /* Remove trailing 0 bytes */
414 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
419 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
421 p_sys->i_state = STATE_NOSYNC;
425 msg_Dbg( p_dec, "pts=%"PRId64" dts=%"PRId64,
426 p_pic->i_pts, p_pic->i_dts );
429 /* So p_block doesn't get re-added several times */
430 *pp_block = block_BytestreamPop( &p_sys->bytestream );
432 p_sys->i_state = STATE_NOSYNC;
439 /****************************************************************************
440 * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
441 * Will always use 4 byte 0 0 0 1 startcodes
442 * Will prepend a SPS and PPS before each keyframe
443 ****************************************************************************/
444 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
446 decoder_sys_t *p_sys = p_dec->p_sys;
448 block_t *p_ret = NULL;
451 if( !pp_block || !*pp_block )
453 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
455 block_Release( *pp_block );
462 for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
468 for( i = 0; i < p_sys->i_avcC_length_size; i++ )
470 i_size = (i_size << 8) | (*p++);
474 i_size > ( p_block->p_buffer + p_block->i_buffer - p ) )
476 msg_Err( p_dec, "Broken frame : size %d is too big", i_size );
480 block_t *p_part = CreateAnnexbNAL( p_dec, p, i_size );
483 p_part->i_dts = p_block->i_dts;
484 p_part->i_pts = p_block->i_pts;
487 if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
489 block_ChainAppend( &p_ret, p_pic );
493 block_Release( p_block );
498 /****************************************************************************
500 ****************************************************************************/
501 static block_t *CreateAnnexbNAL( decoder_t *p_dec, const uint8_t *p, int i_size )
505 p_nal = block_New( p_dec, 4 + i_size );
506 if( !p_nal ) return NULL;
509 p_nal->p_buffer[0] = 0x00;
510 p_nal->p_buffer[1] = 0x00;
511 p_nal->p_buffer[2] = 0x00;
512 p_nal->p_buffer[3] = 0x01;
515 memcpy( &p_nal->p_buffer[4], p, i_size );
521 static void CreateDecodedNAL( uint8_t **pp_ret, int *pi_ret,
522 const uint8_t *src, int i_src )
524 const uint8_t *end = &src[i_src];
525 uint8_t *dst = malloc( i_src );
533 if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
545 *pi_ret = dst - *pp_ret;
548 static inline int bs_read_ue( bs_t *s )
552 while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
556 return( ( 1 << i) - 1 + bs_read( s, i ) );
559 static inline int bs_read_se( bs_t *s )
561 int val = bs_read_ue( s );
563 return val&0x01 ? (val+1)/2 : -(val/2);
566 /*****************************************************************************
567 * ParseNALBlock: parses annexB type NALs
568 * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
569 *****************************************************************************/
570 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
572 decoder_sys_t *p_sys = p_dec->p_sys;
573 block_t *p_pic = NULL;
575 const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
576 const int i_nal_type = p_frag->p_buffer[4]&0x1f;
578 if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
580 block_ChainRelease( p_sys->p_frame );
581 msg_Warn( p_dec, "waiting for SPS/PPS" );
584 p_sys->slice.i_frame_type = 0;
585 p_sys->p_frame = NULL;
586 p_sys->b_slice = false;
589 if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
590 i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
592 p_sys->b_slice = true;
593 /* Fragment will be discarded later on */
595 else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
600 ParseSlice( p_dec, &b_new_picture, &slice, i_nal_ref_idc, i_nal_type, p_frag );
603 if( b_new_picture && p_sys->b_slice )
604 p_pic = OutputPicture( p_dec );
607 p_sys->slice = slice;
608 p_sys->b_slice = true;
610 else if( i_nal_type == NAL_SPS )
613 p_pic = OutputPicture( p_dec );
615 PutSPS( p_dec, p_frag );
617 /* Do not append the SPS because we will insert it on keyframes */
620 else if( i_nal_type == NAL_PPS )
623 p_pic = OutputPicture( p_dec );
625 PutPPS( p_dec, p_frag );
627 /* Do not append the PPS because we will insert it on keyframes */
630 else if( i_nal_type == NAL_AU_DELIMITER ||
631 i_nal_type == NAL_SEI ||
632 ( i_nal_type >= 13 && i_nal_type <= 18 ) )
635 p_pic = OutputPicture( p_dec );
637 /* TODO parse SEI for CC support */
640 /* Append the block */
641 block_ChainAppend( &p_sys->p_frame, p_frag );
646 static block_t *OutputPicture( decoder_t *p_dec )
648 decoder_sys_t *p_sys = p_dec->p_sys;
651 if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I)
654 if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps )
656 block_t *p_sps = block_Duplicate( p_sys->p_sps );
657 block_t *p_pps = block_Duplicate( p_sys->p_pps );
658 p_sps->i_dts = p_sys->p_frame->i_dts;
659 p_sps->i_pts = p_sys->p_frame->i_pts;
660 block_ChainAppend( &p_sps, p_pps );
661 block_ChainAppend( &p_sps, p_sys->p_frame );
662 p_sys->b_header = true;
663 p_pic = block_ChainGather( p_sps );
667 p_pic = block_ChainGather( p_sys->p_frame );
669 p_pic->i_length = 0; /* FIXME */
670 p_pic->i_flags |= p_sys->slice.i_frame_type;
672 p_sys->slice.i_frame_type = 0;
673 p_sys->p_frame = NULL;
674 p_sys->b_slice = false;
679 static void PutSPS( decoder_t *p_dec, block_t *p_frag )
681 decoder_sys_t *p_sys = p_dec->p_sys;
683 uint8_t *pb_dec = NULL;
689 CreateDecodedNAL( &pb_dec, &i_dec, &p_frag->p_buffer[5],
690 p_frag->i_buffer - 5 );
692 bs_init( &s, pb_dec, i_dec );
693 /* Skip profile(8), constraint_set012, reserver(5), level(8) */
694 bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
696 i_sps_id = bs_read_ue( &s );
697 if( i_sps_id >= SPS_MAX )
699 msg_Warn( p_dec, "invalid SPS (sps_id=%d)", i_sps_id );
701 block_Release( p_frag );
705 /* Skip i_log2_max_frame_num */
706 p_sys->i_log2_max_frame_num = bs_read_ue( &s );
707 if( p_sys->i_log2_max_frame_num > 12)
708 p_sys->i_log2_max_frame_num = 12;
710 p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
711 if( p_sys->i_pic_order_cnt_type == 0 )
713 /* skip i_log2_max_poc_lsb */
714 p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
715 if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
716 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
718 else if( p_sys->i_pic_order_cnt_type == 1 )
721 /* skip b_delta_pic_order_always_zero */
722 p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
723 /* skip i_offset_for_non_ref_pic */
725 /* skip i_offset_for_top_to_bottom_field */
727 /* read i_num_ref_frames_in_poc_cycle */
728 i_cycle = bs_read_ue( &s );
729 if( i_cycle > 256 ) i_cycle = 256;
732 /* skip i_offset_for_ref_frame */
736 /* i_num_ref_frames */
738 /* b_gaps_in_frame_num_value_allowed */
742 p_dec->fmt_out.video.i_width = 16 * ( bs_read_ue( &s ) + 1 );
743 p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
745 /* b_frame_mbs_only */
746 p_sys->b_frame_mbs_only = bs_read( &s, 1 );
747 if( p_sys->b_frame_mbs_only == 0 )
751 /* b_direct8x8_inference */
755 i_tmp = bs_read( &s, 1 );
769 i_tmp = bs_read( &s, 1 );
772 /* read the aspect ratio part if any FIXME check it */
773 i_tmp = bs_read( &s, 1 );
776 static const struct { int w, h; } sar[17] =
778 { 0, 0 }, { 1, 1 }, { 12, 11 }, { 10, 11 },
779 { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
780 { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
781 { 64, 33 }, { 160,99 }, { 4, 3 }, { 3, 2 },
784 int i_sar = bs_read( &s, 8 );
792 else if( i_sar == 255 )
794 w = bs_read( &s, 16 );
795 h = bs_read( &s, 16 );
803 p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
804 h * p_dec->fmt_out.video.i_width /
805 p_dec->fmt_out.video.i_height;
807 p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
813 /* We have a new SPS */
815 msg_Dbg( p_dec, "found NAL_SPS (sps_id=%d)", i_sps_id );
819 block_Release( p_sys->p_sps );
820 p_sys->p_sps = p_frag;
823 static void PutPPS( decoder_t *p_dec, block_t *p_frag )
825 decoder_sys_t *p_sys = p_dec->p_sys;
830 bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
831 i_pps_id = bs_read_ue( &s ); // pps id
832 i_sps_id = bs_read_ue( &s ); // sps id
833 if( i_pps_id >= PPS_MAX || i_sps_id >= SPS_MAX )
835 msg_Warn( p_dec, "invalid PPS (pps_id=%d sps_id=%d)", i_pps_id, i_sps_id );
836 block_Release( p_frag );
839 bs_skip( &s, 1 ); // entropy coding mode flag
840 p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
843 /* We have a new PPS */
845 msg_Dbg( p_dec, "found NAL_PPS (pps_id=%d sps_id=%d)", i_pps_id, i_sps_id );
849 block_Release( p_sys->p_pps );
850 p_sys->p_pps = p_frag;
853 static void ParseSlice( decoder_t *p_dec, bool *pb_new_picture, slice_t *p_slice,
854 int i_nal_ref_idc, int i_nal_type, const block_t *p_frag )
856 decoder_sys_t *p_sys = p_dec->p_sys;
859 int i_first_mb, i_slice_type;
863 /* do not convert the whole frame */
864 CreateDecodedNAL( &pb_dec, &i_dec, &p_frag->p_buffer[5],
865 __MIN( p_frag->i_buffer - 5, 60 ) );
866 bs_init( &s, pb_dec, i_dec );
868 /* first_mb_in_slice */
869 i_first_mb = bs_read_ue( &s );
872 switch( (i_slice_type = bs_read_ue( &s )) )
875 slice.i_frame_type = BLOCK_FLAG_TYPE_P;
878 slice.i_frame_type = BLOCK_FLAG_TYPE_B;
881 slice.i_frame_type = BLOCK_FLAG_TYPE_I;
883 case 3: case 8: /* SP */
884 slice.i_frame_type = BLOCK_FLAG_TYPE_P;
887 slice.i_frame_type = BLOCK_FLAG_TYPE_I;
890 slice.i_frame_type = 0;
895 slice.i_nal_type = i_nal_type;
896 slice.i_nal_ref_idc = i_nal_ref_idc;
898 slice.i_pic_parameter_set_id = bs_read_ue( &s );
899 slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
901 slice.i_field_pic_flag = 0;
902 slice.i_bottom_field_flag = -1;
903 if( !p_sys->b_frame_mbs_only )
906 slice.i_field_pic_flag = bs_read( &s, 1 );
907 if( slice.i_field_pic_flag )
908 slice.i_bottom_field_flag = bs_read( &s, 1 );
911 slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
912 if( slice.i_nal_type == NAL_SLICE_IDR )
913 slice.i_idr_pic_id = bs_read_ue( &s );
915 slice.i_pic_order_cnt_lsb = -1;
916 slice.i_delta_pic_order_cnt_bottom = -1;
917 slice.i_delta_pic_order_cnt0 = 0;
918 slice.i_delta_pic_order_cnt1 = 0;
919 if( p_sys->i_pic_order_cnt_type == 0 )
921 slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
922 if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
923 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
925 else if( (p_sys->i_pic_order_cnt_type == 1) &&
926 (!p_sys->i_delta_pic_order_always_zero_flag) )
928 slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
929 if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
930 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
934 /* Detection of the first VCL NAL unit of a primary coded picture
937 if( slice.i_frame_num != p_sys->slice.i_frame_num ||
938 slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
939 slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
940 slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
942 if( (slice.i_bottom_field_flag != -1) &&
943 (p_sys->slice.i_bottom_field_flag != -1) &&
944 (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
946 if( p_sys->i_pic_order_cnt_type == 0 &&
947 ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
948 slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
950 else if( p_sys->i_pic_order_cnt_type == 1 &&
951 ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
952 slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
954 if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
955 ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
959 *pb_new_picture = b_pic;