1 /*****************************************************************************
3 *****************************************************************************
4 * Copyright (C) 2013-2014 L-SMASH project
6 * Authors: Yusuke Nakamura <muken.the.vfrmaniac@gmail.com>
8 * Permission to use, copy, modify, and/or distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 *****************************************************************************/
21 /* This file is available under an ISC license. */
23 #define NALU_DEFAULT_BUFFER_SIZE (1<<16)
24 #define NALU_DEFAULT_NALU_LENGTH_SIZE 4 /* We always use 4 bytes length. */
25 #define NALU_SHORT_START_CODE_LENGTH 3
26 #define NALU_LONG_START_CODE_LENGTH 4
27 #define NALU_NO_START_CODE_FOUND UINT64_MAX
29 static inline uint64_t nalu_get_codeNum
34 uint32_t leadingZeroBits
= 0;
35 for( int b
= 0; !b
; leadingZeroBits
++ )
36 b
= lsmash_bits_get( bits
, 1 );
38 return ((uint64_t)1 << leadingZeroBits
) - 1 + lsmash_bits_get( bits
, leadingZeroBits
);
41 static inline uint64_t nalu_decode_exp_golomb_ue
49 static inline int64_t nalu_decode_exp_golomb_se
55 return (int64_t)((codeNum
>> 1) + 1);
56 return -1 * (int64_t)(codeNum
>> 1);
59 static inline uint64_t nalu_get_exp_golomb_ue
64 uint64_t codeNum
= nalu_get_codeNum( bits
);
65 return nalu_decode_exp_golomb_ue( codeNum
);
68 static inline uint64_t nalu_get_exp_golomb_se
73 uint64_t codeNum
= nalu_get_codeNum( bits
);
74 return nalu_decode_exp_golomb_se( codeNum
);
77 /* Convert EBSP (Encapsulated Byte Sequence Packets) to RBSP (Raw Byte Sequence Packets). */
78 static inline uint8_t *nalu_remove_emulation_prevention
85 uint8_t *src_end
= src
+ src_length
;
86 while( src
< src_end
)
87 if( ((src
+ 2) < src_end
) && !src
[0] && !src
[1] && (src
[2] == 0x03) )
89 /* 0x000003 -> 0x0000 */
92 src
++; /* Skip emulation_prevention_three_byte (0x03). */
99 static inline int nalu_import_rbsp_from_ebsp
102 uint8_t *rbsp_buffer
,
107 uint8_t *rbsp_start
= rbsp_buffer
;
108 uint8_t *rbsp_end
= nalu_remove_emulation_prevention( ebsp
, ebsp_size
, rbsp_buffer
);
109 uint64_t rbsp_length
= rbsp_end
- rbsp_start
;
110 return lsmash_bits_import_data( bits
, rbsp_start
, rbsp_length
);
113 static inline int nalu_check_more_rbsp_data
118 lsmash_bs_t
*bs
= bits
->bs
;
119 lsmash_buffer_t
*buffer
= &bs
->buffer
;
120 if( buffer
->pos
< buffer
->store
&& !(bits
->store
== 0 && (buffer
->store
== buffer
->pos
+ 1)) )
121 return 1; /* rbsp_trailing_bits will be placed at the next or later byte.
122 * Note: bs->pos points at the next byte if bits->store isn't empty. */
123 if( bits
->store
== 0 )
125 if( buffer
->store
== buffer
->pos
+ 1 )
126 return buffer
->data
[ buffer
->pos
] != 0x80;
127 /* No rbsp_trailing_bits is present in RBSP data. */
131 /* Check whether remainder of bits is identical to rbsp_trailing_bits. */
132 uint8_t remainder_bits
= bits
->cache
& ~(~0U << bits
->store
);
133 uint8_t rbsp_trailing_bits
= 1U << (bits
->store
- 1);
134 return remainder_bits
!= rbsp_trailing_bits
;
137 static inline int nalu_get_max_ps_length
139 lsmash_entry_list_t
*ps_list
,
140 uint32_t *max_ps_length
144 for( lsmash_entry_t
*entry
= ps_list
->head
; entry
; entry
= entry
->next
)
146 isom_dcr_ps_entry_t
*ps
= (isom_dcr_ps_entry_t
*)entry
->data
;
151 *max_ps_length
= LSMASH_MAX( *max_ps_length
, ps
->nalUnitLength
);
156 static inline int nalu_get_ps_count
158 lsmash_entry_list_t
*ps_list
,
163 for( lsmash_entry_t
*entry
= ps_list
? ps_list
->head
: NULL
; entry
; entry
= entry
->next
)
165 isom_dcr_ps_entry_t
*ps
= (isom_dcr_ps_entry_t
*)entry
->data
;
175 static inline int nalu_check_same_ps_existence
177 lsmash_entry_list_t
*ps_list
,
182 for( lsmash_entry_t
*entry
= ps_list
->head
; entry
; entry
= entry
->next
)
184 isom_dcr_ps_entry_t
*ps
= (isom_dcr_ps_entry_t
*)entry
->data
;
189 if( ps
->nalUnitLength
== ps_length
&& !memcmp( ps
->nalUnit
, ps_data
, ps_length
) )
190 return 1; /* The same parameter set already exists. */
195 static inline int nalu_get_dcr_ps
198 lsmash_entry_list_t
*list
,
202 for( uint8_t i
= 0; i
< entry_count
; i
++ )
204 isom_dcr_ps_entry_t
*data
= lsmash_malloc( sizeof(isom_dcr_ps_entry_t
) );
207 if( lsmash_add_entry( list
, data
) )
212 data
->nalUnitLength
= lsmash_bs_get_be16( bs
);
213 data
->nalUnit
= lsmash_bs_get_bytes( bs
, data
->nalUnitLength
);
216 lsmash_remove_entries( list
, isom_remove_dcr_ps
);
223 static inline int nalu_check_next_short_start_code
229 return ((buf_pos
+ 2) < buf_end
) && !buf_pos
[0] && !buf_pos
[1] && (buf_pos
[2] == 0x01);
232 /* Return the offset from the beginning of stream if a start code is found.
233 * Return NALU_NO_START_CODE_FOUND otherwise. */
234 static inline uint64_t nalu_find_first_start_code
239 uint64_t first_sc_head_pos
= 0;
242 if( lsmash_bs_is_end( bs
, first_sc_head_pos
+ NALU_LONG_START_CODE_LENGTH
) )
243 return NALU_NO_START_CODE_FOUND
;
244 /* Invalid if encountered any value of non-zero before the first start code. */
245 if( lsmash_bs_show_byte( bs
, first_sc_head_pos
) )
246 return NALU_NO_START_CODE_FOUND
;
247 /* The first NALU of an AU in decoding order shall have long start code (0x00000001). */
248 if( 0x00000001 == lsmash_bs_show_be32( bs
, first_sc_head_pos
) )
252 return first_sc_head_pos
;