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;
88 block_bytestream_t bytestream;
102 int i_avcC_length_size;
106 /* Useful values of the Sequence Parameter Set */
107 int i_log2_max_frame_num;
108 int b_frame_mbs_only;
109 int i_pic_order_cnt_type;
110 int i_delta_pic_order_always_zero_flag;
111 int i_log2_max_pic_order_cnt_lsb;
113 /* Value from Picture Parameter Set */
114 int i_pic_order_present_flag;
116 /* Useful values of the Slice Header */
133 NAL_SLICE_IDR = 5, /* ref_idc != 0 */
134 NAL_SEI = 6, /* ref_idc == 0 */
138 /* ref_idc == 0 for 6,9,10,11,12 */
143 NAL_PRIORITY_DISPOSABLE = 0,
144 NAL_PRIORITY_LOW = 1,
145 NAL_PRIORITY_HIGH = 2,
146 NAL_PRIORITY_HIGHEST = 3,
149 static block_t *ParseNALBlock( decoder_t *, block_t * );
151 static block_t *nal_get_annexeb( decoder_t *, uint8_t *p, int );
153 static block_t *OutputPicture( decoder_t *p_dec );
154 static void PutSPS( decoder_t *p_dec, block_t *p_frag );
155 static void PutPPS( decoder_t *p_dec, block_t *p_frag );
156 static void ParseSlice( decoder_t *p_dec, bool *pb_new_picture, slice_t *p_slice,
157 int i_nal_ref_idc, int i_nal_type, const block_t *p_frag );
160 /*****************************************************************************
161 * Open: probe the packetizer and return score
162 * When opening after demux, the packetizer is only loaded AFTER the decoder
163 * That means that what you set in fmt_out is ignored by the decoder in this special case
164 *****************************************************************************/
165 static int Open( vlc_object_t *p_this )
167 decoder_t *p_dec = (decoder_t*)p_this;
168 decoder_sys_t *p_sys;
170 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'h', '2', '6', '4') &&
171 p_dec->fmt_in.i_codec != VLC_FOURCC( 'H', '2', '6', '4') &&
172 p_dec->fmt_in.i_codec != VLC_FOURCC( 'V', 'S', 'S', 'H') &&
173 p_dec->fmt_in.i_codec != VLC_FOURCC( 'v', 's', 's', 'h') &&
174 p_dec->fmt_in.i_codec != VLC_FOURCC( 'D', 'A', 'V', 'C') &&
175 ( p_dec->fmt_in.i_codec != VLC_FOURCC( 'a', 'v', 'c', '1') ||
176 p_dec->fmt_in.i_extra < 7 ) )
181 /* Allocate the memory needed to store the decoder's structure */
182 if( ( p_dec->p_sys = p_sys = malloc( sizeof(decoder_sys_t) ) ) == NULL )
186 p_sys->i_state = STATE_NOSYNC;
188 p_sys->startcode[0] = 0;
189 p_sys->startcode[1] = 0;
190 p_sys->startcode[2] = 0;
191 p_sys->startcode[3] = 1;
192 p_sys->bytestream = block_BytestreamInit();
193 p_sys->b_slice = false;
194 p_sys->p_frame = NULL;
195 p_sys->b_sps = false;
196 p_sys->b_pps = false;
199 p_sys->b_header= false;
201 p_sys->slice.i_nal_type = -1;
202 p_sys->slice.i_nal_ref_idc = -1;
203 p_sys->slice.i_idr_pic_id = -1;
204 p_sys->slice.i_frame_num = -1;
205 p_sys->slice.i_frame_type = 0;
206 p_sys->slice.i_pic_parameter_set_id = -1;
207 p_sys->slice.i_field_pic_flag = 0;
208 p_sys->slice.i_bottom_field_flag = -1;
209 p_sys->slice.i_pic_order_cnt_lsb = -1;
210 p_sys->slice.i_delta_pic_order_cnt_bottom = -1;
212 /* Setup properties */
213 es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
214 p_dec->fmt_out.i_codec = VLC_FOURCC( 'h', '2', '6', '4' );
216 if( p_dec->fmt_in.i_codec == VLC_FOURCC( 'a', 'v', 'c', '1' ) )
218 /* This type of stream is produced by mp4 and matroska
219 * when we want to store it in another streamformat, you need to convert
220 * The fmt_in.p_extra should ALWAYS contain the avcC
221 * The fmt_out.p_extra should contain all the SPS and PPS with 4 byte startcodes */
222 uint8_t *p = &((uint8_t*)p_dec->fmt_in.p_extra)[4];
227 p_sys->i_avcC_length_size = 1 + ((*p++)&0x03);
231 for( i = 0; i < i_sps; i++ )
233 uint16_t i_length = GetWBE( p ); p += 2;
235 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
239 block_t *p_sps = nal_get_annexeb( p_dec, p, i_length );
242 ParseNALBlock( p_dec, p_sps );
247 for( i = 0; i < i_pps; i++ )
249 uint16_t i_length = GetWBE( p ); p += 2;
251 (uint8_t*)p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra - p )
255 block_t *p_pps = nal_get_annexeb( p_dec, p, i_length );
258 ParseNALBlock( p_dec, p_pps );
261 msg_Dbg( p_dec, "avcC length size=%d, sps=%d, pps=%d",
262 p_sys->i_avcC_length_size, i_sps, i_pps );
264 if( !p_sys->p_sps || p_sys->p_pps )
267 /* FIXME: FFMPEG isn't happy at all if you leave this */
268 if( p_dec->fmt_out.i_extra > 0 ) free( p_dec->fmt_out.p_extra );
269 p_dec->fmt_out.i_extra = 0;
270 p_dec->fmt_out.p_extra = NULL;
272 /* Set the new extradata */
273 p_dec->fmt_out.i_extra = p_sys->p_pps->i_buffer + p_sys->p_sps->i_buffer;
274 p_dec->fmt_out.p_extra = malloc( p_dec->fmt_out.i_extra );
275 if( p_dec->fmt_out.p_extra )
277 memcpy( (uint8_t*)p_dec->fmt_out.p_extra,
278 p_sys->p_sps->p_buffer, p_sys->p_sps->i_buffer);
279 memcpy( (uint8_t*)p_dec->fmt_out.p_extra+p_sys->p_sps->i_buffer,
280 p_sys->p_pps->p_buffer, p_sys->p_pps->i_buffer);
281 p_sys->b_header = true;
283 else p_dec->fmt_out.i_extra = 0;
286 p_dec->pf_packetize = PacketizeAVC1;
290 /* This type of stream contains data with 3 of 4 byte startcodes
291 * The fmt_in.p_extra MAY contain SPS/PPS with 4 byte startcodes
292 * The fmt_out.p_extra should be the same */
295 p_dec->pf_packetize = Packetize;
298 if( p_dec->fmt_in.i_extra > 0 )
300 block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
303 memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
304 p_dec->fmt_in.i_extra );
306 while( ( p_pic = Packetize( p_dec, &p_init ) ) )
308 /* Should not occur because we should only receive SPS/PPS */
309 block_Release( p_pic );
317 /*****************************************************************************
318 * Close: clean up the packetizer
319 *****************************************************************************/
320 static void Close( vlc_object_t *p_this )
322 decoder_t *p_dec = (decoder_t*)p_this;
323 decoder_sys_t *p_sys = p_dec->p_sys;
325 if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
326 if( p_sys->p_sps ) block_Release( p_sys->p_sps );
327 if( p_sys->p_pps ) block_Release( p_sys->p_pps );
328 block_BytestreamRelease( &p_sys->bytestream );
332 /****************************************************************************
333 * Packetize: the whole thing
334 * Search for the startcodes 3 or more bytes
335 * Feed ParseNALBlock ALWAYS with 4 byte startcode prepended NALs
336 ****************************************************************************/
337 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
339 decoder_sys_t *p_sys = p_dec->p_sys;
342 if( !pp_block || !*pp_block )
345 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
347 if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
349 p_sys->i_state = STATE_NOSYNC;
350 block_BytestreamFlush( &p_sys->bytestream );
353 block_ChainRelease( p_sys->p_frame );
354 p_sys->p_frame = NULL;
355 p_sys->slice.i_frame_type = 0;
356 p_sys->b_slice = false;
358 block_Release( *pp_block );
362 block_BytestreamPush( &p_sys->bytestream, *pp_block );
366 switch( p_sys->i_state )
369 /* Skip until 3 byte startcode 0 0 1 */
370 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
371 &p_sys->i_offset, p_sys->startcode+1, 3 ) == VLC_SUCCESS)
373 p_sys->i_state = STATE_NEXT_SYNC;
376 if( p_sys->i_offset )
379 block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
381 block_BytestreamFlush( &p_sys->bytestream );
384 if( p_sys->i_state != STATE_NEXT_SYNC )
390 p_sys->i_offset = 1; /* To find next startcode */
392 case STATE_NEXT_SYNC:
393 /* Find the next 3 byte startcode 0 0 1*/
394 if( block_FindStartcodeFromOffset( &p_sys->bytestream,
395 &p_sys->i_offset, p_sys->startcode+1, 3 ) != VLC_SUCCESS)
401 /* Get the new fragment and set the pts/dts */
402 p_pic = block_New( p_dec, p_sys->i_offset +1 );
403 p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
404 p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
405 /* Force 4 byte startcode 0 0 0 1 */
406 p_pic->p_buffer[0] = 0;
408 block_GetBytes( &p_sys->bytestream, &p_pic->p_buffer[1],
411 /* Remove trailing 0 bytes */
412 while( p_pic->i_buffer && (!p_pic->p_buffer[p_pic->i_buffer-1] ) )
417 if( !( p_pic = ParseNALBlock( p_dec, p_pic ) ) )
419 p_sys->i_state = STATE_NOSYNC;
423 msg_Dbg( p_dec, "pts=%"PRId64" dts=%"PRId64,
424 p_pic->i_pts, p_pic->i_dts );
427 /* So p_block doesn't get re-added several times */
428 *pp_block = block_BytestreamPop( &p_sys->bytestream );
430 p_sys->i_state = STATE_NOSYNC;
437 /****************************************************************************
438 * PacketizeAVC1: Takes VCL blocks of data and creates annexe B type NAL stream
439 * Will always use 4 byte 0 0 0 1 startcodes
440 * Will prepend a SPS and PPS before each keyframe
441 ****************************************************************************/
442 static block_t *PacketizeAVC1( decoder_t *p_dec, block_t **pp_block )
444 decoder_sys_t *p_sys = p_dec->p_sys;
446 block_t *p_ret = NULL;
449 if( !pp_block || !*pp_block )
451 if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
453 block_Release( *pp_block );
460 for( p = p_block->p_buffer; p < &p_block->p_buffer[p_block->i_buffer]; )
466 for( i = 0; i < p_sys->i_avcC_length_size; i++ )
468 i_size = (i_size << 8) | (*p++);
472 i_size > ( p_block->p_buffer + p_block->i_buffer - p ) )
474 msg_Err( p_dec, "Broken frame : size %d is too big", i_size );
478 block_t *p_part = nal_get_annexeb( p_dec, p, i_size );
481 p_part->i_dts = p_block->i_dts;
482 p_part->i_pts = p_block->i_pts;
485 if( ( p_pic = ParseNALBlock( p_dec, p_part ) ) )
487 block_ChainAppend( &p_ret, p_pic );
491 block_Release( p_block );
496 static block_t *nal_get_annexeb( decoder_t *p_dec, uint8_t *p, int i_size )
500 p_nal = block_New( p_dec, 4 + i_size );
501 if( !p_nal ) return NULL;
504 p_nal->p_buffer[0] = 0x00;
505 p_nal->p_buffer[1] = 0x00;
506 p_nal->p_buffer[2] = 0x00;
507 p_nal->p_buffer[3] = 0x01;
510 memcpy( &p_nal->p_buffer[4], p, i_size );
516 static void nal_get_decoded( uint8_t **pp_ret, int *pi_ret,
517 uint8_t *src, int i_src )
519 uint8_t *end = &src[i_src];
520 uint8_t *dst = malloc( i_src );
528 if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
540 *pi_ret = dst - *pp_ret;
543 static inline int bs_read_ue( bs_t *s )
547 while( bs_read1( s ) == 0 && s->p < s->p_end && i < 32 )
551 return( ( 1 << i) - 1 + bs_read( s, i ) );
554 static inline int bs_read_se( bs_t *s )
556 int val = bs_read_ue( s );
558 return val&0x01 ? (val+1)/2 : -(val/2);
561 /*****************************************************************************
562 * ParseNALBlock: parses annexB type NALs
563 * All p_frag blocks are required to start with 0 0 0 1 4-byte startcode
564 *****************************************************************************/
565 static block_t *ParseNALBlock( decoder_t *p_dec, block_t *p_frag )
567 decoder_sys_t *p_sys = p_dec->p_sys;
568 block_t *p_pic = NULL;
570 const int i_nal_ref_idc = (p_frag->p_buffer[4] >> 5)&0x03;
571 const int i_nal_type = p_frag->p_buffer[4]&0x1f;
573 if( p_sys->b_slice && ( !p_sys->b_sps || !p_sys->b_pps ) )
575 block_ChainRelease( p_sys->p_frame );
576 msg_Warn( p_dec, "waiting for SPS/PPS" );
579 p_sys->slice.i_frame_type = 0;
580 p_sys->p_frame = NULL;
581 p_sys->b_slice = false;
584 if( ( !p_sys->b_sps || !p_sys->b_pps ) &&
585 i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
587 p_sys->b_slice = true;
588 /* Fragment will be discarded later on */
590 else if( i_nal_type >= NAL_SLICE && i_nal_type <= NAL_SLICE_IDR )
595 ParseSlice( p_dec, &b_new_picture, &slice, i_nal_ref_idc, i_nal_type, p_frag );
598 if( b_new_picture && p_sys->b_slice )
599 p_pic = OutputPicture( p_dec );
602 p_sys->slice = slice;
603 p_sys->b_slice = true;
605 else if( i_nal_type == NAL_SPS )
608 p_pic = OutputPicture( p_dec );
610 PutSPS( p_dec, p_frag );
612 /* Do not append the SPS because we will insert it on keyframes */
615 else if( i_nal_type == NAL_PPS )
618 p_pic = OutputPicture( p_dec );
620 PutPPS( p_dec, p_frag );
622 /* Do not append the PPS because we will insert it on keyframes */
625 else if( i_nal_type == NAL_AU_DELIMITER ||
626 i_nal_type == NAL_SEI ||
627 ( i_nal_type >= 13 && i_nal_type <= 18 ) )
630 p_pic = OutputPicture( p_dec );
633 /* Append the block */
634 block_ChainAppend( &p_sys->p_frame, p_frag );
639 static block_t *OutputPicture( decoder_t *p_dec )
641 decoder_sys_t *p_sys = p_dec->p_sys;
644 if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I)
647 if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->p_sps && p_sys->p_pps )
649 block_t *p_sps = block_Duplicate( p_sys->p_sps );
650 block_t *p_pps = block_Duplicate( p_sys->p_pps );
651 p_sps->i_dts = p_sys->p_frame->i_dts;
652 p_sps->i_pts = p_sys->p_frame->i_pts;
653 block_ChainAppend( &p_sps, p_pps );
654 block_ChainAppend( &p_sps, p_sys->p_frame );
655 p_sys->b_header = true;
656 p_pic = block_ChainGather( p_sps );
660 p_pic = block_ChainGather( p_sys->p_frame );
662 p_pic->i_length = 0; /* FIXME */
663 p_pic->i_flags |= p_sys->slice.i_frame_type;
665 p_sys->slice.i_frame_type = 0;
666 p_sys->p_frame = NULL;
667 p_sys->b_slice = false;
672 static void PutSPS( decoder_t *p_dec, block_t *p_frag )
674 decoder_sys_t *p_sys = p_dec->p_sys;
682 msg_Dbg( p_dec, "found NAL_SPS" );
686 nal_get_decoded( &dec, &i_dec, &p_frag->p_buffer[5],
687 p_frag->i_buffer - 5 );
689 bs_init( &s, dec, i_dec );
690 /* Skip profile(8), constraint_set012, reserver(5), level(8) */
691 bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
694 /* Skip i_log2_max_frame_num */
695 p_sys->i_log2_max_frame_num = bs_read_ue( &s );
696 if( p_sys->i_log2_max_frame_num > 12)
697 p_sys->i_log2_max_frame_num = 12;
699 p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
700 if( p_sys->i_pic_order_cnt_type == 0 )
702 /* skip i_log2_max_poc_lsb */
703 p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
704 if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
705 p_sys->i_log2_max_pic_order_cnt_lsb = 12;
707 else if( p_sys->i_pic_order_cnt_type == 1 )
710 /* skip b_delta_pic_order_always_zero */
711 p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
712 /* skip i_offset_for_non_ref_pic */
714 /* skip i_offset_for_top_to_bottom_field */
716 /* read i_num_ref_frames_in_poc_cycle */
717 i_cycle = bs_read_ue( &s );
718 if( i_cycle > 256 ) i_cycle = 256;
721 /* skip i_offset_for_ref_frame */
725 /* i_num_ref_frames */
727 /* b_gaps_in_frame_num_value_allowed */
731 p_dec->fmt_out.video.i_width = 16 * ( bs_read_ue( &s ) + 1 );
732 p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );
734 /* b_frame_mbs_only */
735 p_sys->b_frame_mbs_only = bs_read( &s, 1 );
736 if( p_sys->b_frame_mbs_only == 0 )
740 /* b_direct8x8_inference */
744 i_tmp = bs_read( &s, 1 );
758 i_tmp = bs_read( &s, 1 );
761 /* read the aspect ratio part if any FIXME check it */
762 i_tmp = bs_read( &s, 1 );
765 static const struct { int w, h; } sar[14] =
767 { 0, 0 }, { 1, 1 }, { 12, 11 }, { 10, 11 },
768 { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
769 { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
770 { 64, 33 }, { 160,99 },
772 int i_sar = bs_read( &s, 8 );
782 w = bs_read( &s, 16 );
783 h = bs_read( &s, 16 );
786 p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * w /
787 h * p_dec->fmt_out.video.i_width /
788 p_dec->fmt_out.video.i_height;
790 p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
796 /* We have a new SPS */
798 block_Release( p_sys->p_sps );
799 p_sys->p_sps = p_frag;
802 static void PutPPS( decoder_t *p_dec, block_t *p_frag )
804 decoder_sys_t *p_sys = p_dec->p_sys;
807 bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
808 bs_read_ue( &s ); // pps id
809 bs_read_ue( &s ); // sps id
810 bs_skip( &s, 1 ); // entropy coding mode flag
811 p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
814 msg_Dbg( p_dec, "found NAL_PPS" );
819 /* We have a new PPS */
821 block_Release( p_sys->p_pps );
822 p_sys->p_pps = p_frag;
825 static void ParseSlice( decoder_t *p_dec, bool *pb_new_picture, slice_t *p_slice,
826 int i_nal_ref_idc, int i_nal_type, const block_t *p_frag )
828 decoder_sys_t *p_sys = p_dec->p_sys;
831 int i_first_mb, i_slice_type;
835 /* do not convert the whole frame */
836 nal_get_decoded( &pb_dec, &i_dec, &p_frag->p_buffer[5],
837 __MIN( p_frag->i_buffer - 5, 60 ) );
838 bs_init( &s, pb_dec, i_dec );
840 /* first_mb_in_slice */
841 i_first_mb = bs_read_ue( &s );
844 switch( (i_slice_type = bs_read_ue( &s )) )
847 slice.i_frame_type = BLOCK_FLAG_TYPE_P;
850 slice.i_frame_type = BLOCK_FLAG_TYPE_B;
853 slice.i_frame_type = BLOCK_FLAG_TYPE_I;
855 case 3: case 8: /* SP */
856 slice.i_frame_type = BLOCK_FLAG_TYPE_P;
859 slice.i_frame_type = BLOCK_FLAG_TYPE_I;
862 slice.i_frame_type = 0;
867 slice.i_nal_type = i_nal_type;
868 slice.i_nal_ref_idc = i_nal_ref_idc;
870 slice.i_pic_parameter_set_id = bs_read_ue( &s );
871 slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );
873 slice.i_field_pic_flag = 0;
874 slice.i_bottom_field_flag = -1;
875 if( !p_sys->b_frame_mbs_only )
878 slice.i_field_pic_flag = bs_read( &s, 1 );
879 if( slice.i_field_pic_flag )
880 slice.i_bottom_field_flag = bs_read( &s, 1 );
883 slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
884 if( slice.i_nal_type == NAL_SLICE_IDR )
885 slice.i_idr_pic_id = bs_read_ue( &s );
887 slice.i_pic_order_cnt_lsb = -1;
888 slice.i_delta_pic_order_cnt_bottom = -1;
889 slice.i_delta_pic_order_cnt0 = 0;
890 slice.i_delta_pic_order_cnt1 = 0;
891 if( p_sys->i_pic_order_cnt_type == 0 )
893 slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
894 if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
895 slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
897 else if( (p_sys->i_pic_order_cnt_type == 1) &&
898 (!p_sys->i_delta_pic_order_always_zero_flag) )
900 slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
901 if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
902 slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
906 /* Detection of the first VCL NAL unit of a primary coded picture
909 if( slice.i_frame_num != p_sys->slice.i_frame_num ||
910 slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
911 slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
912 slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
914 if( (slice.i_bottom_field_flag != -1) &&
915 (p_sys->slice.i_bottom_field_flag != -1) &&
916 (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
918 if( p_sys->i_pic_order_cnt_type == 0 &&
919 ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
920 slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
922 else if( p_sys->i_pic_order_cnt_type == 1 &&
923 ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
924 slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
926 if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
927 ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
931 *pb_new_picture = b_pic;