1 /*****************************************************************************
2 * input_ext-dec.h: structures exported to the VideoLAN decoders
3 *****************************************************************************
4 * Copyright (C) 1999-2001 VideoLAN
5 * $Id: input_ext-dec.h,v 1.76 2002/11/09 16:34:52 sam Exp $
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
8 * Michel Kaempf <maxx@via.ecp.fr>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
23 *****************************************************************************/
25 #ifndef _VLC_INPUT_EXT_DEC_H
26 #define _VLC_INPUT_EXT_DEC_H 1
28 /* Structures exported to the decoders */
30 /*****************************************************************************
32 *****************************************************************************
33 * Describe a data packet.
34 *****************************************************************************/
37 /* Used to chain the packets that carry data for a same PES or PSI */
38 data_packet_t * p_next;
40 /* start of the PS or TS packet */
41 byte_t * p_demux_start;
42 /* start of the PES payload in this packet */
43 byte_t * p_payload_start;
44 byte_t * p_payload_end; /* guess ? :-) */
45 /* is the packet messed up ? */
46 vlc_bool_t b_discard_payload;
48 /* pointer to the real data */
49 data_buffer_t * p_buffer;
52 /*****************************************************************************
54 *****************************************************************************
55 * Describes an PES packet, with its properties, and pointers to the TS packets
57 *****************************************************************************/
60 /* Chained list to the next PES packet (depending on the context) */
61 pes_packet_t * p_next;
64 vlc_bool_t b_data_alignment; /* used to find the beginning of
65 * a video or audio unit */
66 vlc_bool_t b_discontinuity; /* This packet doesn't follow the
69 mtime_t i_pts; /* PTS for this packet (zero if unset) */
70 mtime_t i_dts; /* DTS for this packet (zero if unset) */
71 int i_rate; /* current reading pace (see stream_control.h) */
73 unsigned int i_pes_size; /* size of the current PES packet */
75 /* Chained list to packets */
76 data_packet_t * p_first; /* The first packet contained by this
77 * PES (used by decoders). */
78 data_packet_t * p_last; /* The last packet contained by this
79 * PES (used by the buffer allocator) */
80 unsigned int i_nb_data; /* Number of data packets in the chained list */
83 /*****************************************************************************
85 *****************************************************************************
86 * This rotative FIFO contains PES packets that are to be decoded.
87 *****************************************************************************/
92 /* Thread structures */
93 vlc_mutex_t data_lock; /* fifo data lock */
94 vlc_cond_t data_wait; /* fifo data conditional variable */
97 pes_packet_t * p_first;
98 pes_packet_t ** pp_last;
99 int i_depth; /* number of PES packets in the stack */
101 /* Communication interface between input and decoders */
102 input_buffers_t *p_packets_mgt; /* packets management services data */
104 /* Standard pointers given to the decoders as a toolbox. */
106 vlc_fourcc_t i_fourcc;
107 es_sys_t * p_demux_data;
108 stream_ctrl_t * p_stream_ctrl;
109 sout_instance_t * p_sout;
111 /* Module properties */
113 int ( * pf_run ) ( decoder_fifo_t * );
116 /*****************************************************************************
117 * bit_fifo_t : bit fifo descriptor
118 *****************************************************************************
119 * This type describes a bit fifo used to store bits while working with the
120 * input stream at the bit level.
121 *****************************************************************************/
122 typedef u32 WORD_TYPE;
124 typedef struct bit_fifo_t
126 /* This unsigned integer allows us to work at the bit level. This buffer
127 * can contain 32 bits, and the used space can be found on the MSb's side
128 * and the available space on the LSb's side. */
131 /* Number of bits available in the bit buffer */
136 /*****************************************************************************
137 * bit_stream_t : bit stream descriptor
138 *****************************************************************************
139 * This type, based on a PES stream, includes all the structures needed to
140 * handle the input stream like a bit stream.
141 *****************************************************************************/
152 /* The decoder fifo contains the data of the PES stream */
153 decoder_fifo_t * p_decoder_fifo;
155 /* Callback to the decoder used when changing data packets ; set
156 * to NULL if your decoder doesn't need it. */
157 void (* pf_bitstream_callback)( bit_stream_t *, vlc_bool_t );
158 /* Optional argument to the callback */
159 void * p_callback_arg;
164 mtime_t i_pts, i_dts;
165 byte_t * p_pts_validity;
170 /* Current PES packet (extracted from the PES stream) */
171 pes_packet_t * p_pes;
172 /* Current data packet (in the current PES packet) */
173 data_packet_t * p_data;
174 /* Pointer to the next byte that is to be read (in the current packet) */
176 /* Pointer to the last byte that is to be read (in the current packet */
178 /* Temporary buffer in case we're not aligned when changing data packets */
179 WORD_TYPE i_showbits_buffer;
180 data_packet_t showbits_data;
183 /*****************************************************************************
184 * Inline functions used by the decoders to read bit_stream_t
185 *****************************************************************************/
188 * DISCUSSION : How to use the bit_stream structures
190 * sizeof(WORD_TYPE) (usually 32) bits are read at the same time, thus
191 * minimizing the number of p_byte changes.
192 * Bits are read via GetBits() or ShowBits.
194 * XXX : Be aware that if, in the forthcoming functions, i_bits > 24,
195 * the data have to be already aligned on an 8-bit boundary, or wrong
196 * results will be returned. Use RealignBits() if unsure.
199 #if (WORD_TYPE == u32)
200 # define WORD_AT U32_AT
201 # define WORD_SIGNED s32
202 #elif (WORD_TYPE == u64)
203 # define WORD_AT U64_AT
204 # define WORD_SIGNED s64
206 # error Unsupported WORD_TYPE
209 /*****************************************************************************
210 * Prototypes from input_ext-dec.c
211 *****************************************************************************/
212 VLC_EXPORT( int, InitBitstream, ( bit_stream_t *, decoder_fifo_t *, void ( * )( bit_stream_t *, vlc_bool_t ), void * p_callback_arg ) );
213 VLC_EXPORT( vlc_bool_t, NextDataPacket, ( decoder_fifo_t *, bit_stream_t * ) );
214 VLC_EXPORT( void, BitstreamNextDataPacket, ( bit_stream_t * ) );
215 VLC_EXPORT( u32, UnalignedShowBits, ( bit_stream_t *, unsigned int ) );
216 VLC_EXPORT( void, UnalignedRemoveBits, ( bit_stream_t * ) );
217 VLC_EXPORT( u32, UnalignedGetBits, ( bit_stream_t *, unsigned int ) );
218 VLC_EXPORT( void, CloseBitstream, ( bit_stream_t * ) );
219 VLC_EXPORT( void, CurrentPTS, ( bit_stream_t *, mtime_t *, mtime_t * ) );
220 VLC_EXPORT( void, NextPTS, ( bit_stream_t *, mtime_t *, mtime_t * ) );
222 /*****************************************************************************
223 * AlignWord : fill in the bit buffer so that the byte pointer be aligned
224 * on a word boundary (XXX: there must be at least sizeof(WORD_TYPE) - 1
225 * empty bytes in the bit buffer)
226 *****************************************************************************/
227 static inline void AlignWord( bit_stream_t * p_bit_stream )
229 while( (ptrdiff_t)p_bit_stream->p_byte
230 & (sizeof(WORD_TYPE) - 1) )
232 if( p_bit_stream->p_byte < p_bit_stream->p_end )
234 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
235 << (8 * sizeof(WORD_TYPE) - 8
236 - p_bit_stream->fifo.i_available);
237 p_bit_stream->fifo.i_available += 8;
241 BitstreamNextDataPacket( p_bit_stream );
242 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
243 << (8 * sizeof(WORD_TYPE) - 8
244 - p_bit_stream->fifo.i_available);
245 p_bit_stream->fifo.i_available += 8;
250 /*****************************************************************************
251 * ShowBits : return i_bits bits from the bit stream
252 *****************************************************************************/
253 static inline u32 ShowBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
255 if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
257 return( p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits) );
260 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
262 return( (p_bit_stream->fifo.buffer |
263 (WORD_AT( p_bit_stream->p_byte )
264 >> p_bit_stream->fifo.i_available))
265 >> (8 * sizeof(WORD_TYPE) - i_bits) );
268 return( UnalignedShowBits( p_bit_stream, i_bits ) );
271 /*****************************************************************************
272 * ShowSignedBits : return i_bits bits from the bit stream, using signed
274 *****************************************************************************/
275 static inline s32 ShowSignedBits( bit_stream_t * p_bit_stream,
276 unsigned int i_bits )
278 if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
280 return( (WORD_SIGNED)p_bit_stream->fifo.buffer
281 >> (8 * sizeof(WORD_TYPE) - i_bits) );
284 /* You can probably do something a little faster, but now I'm tired. */
285 return( (WORD_SIGNED)(ShowBits( p_bit_stream, i_bits ) << (32 - i_bits))
289 /*****************************************************************************
290 * RemoveBits : removes i_bits bits from the bit buffer
291 * XXX: do not use for 32 bits, see RemoveBits32
292 *****************************************************************************/
293 static inline void RemoveBits( bit_stream_t * p_bit_stream,
294 unsigned int i_bits )
296 p_bit_stream->fifo.i_available -= i_bits;
298 if( p_bit_stream->fifo.i_available >= 0 )
300 p_bit_stream->fifo.buffer <<= i_bits;
304 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
306 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
307 << ( -p_bit_stream->fifo.i_available );
308 p_bit_stream->p_byte =
309 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
310 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
314 UnalignedRemoveBits( p_bit_stream );
317 /*****************************************************************************
318 * RemoveBits32 : removes 32 bits from the bit buffer (and as a side effect,
320 *****************************************************************************/
321 #if (WORD_TYPE == u32)
322 static inline void RemoveBits32( bit_stream_t * p_bit_stream )
324 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
326 if( p_bit_stream->fifo.i_available )
328 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
329 << (32 - p_bit_stream->fifo.i_available);
330 p_bit_stream->p_byte =
331 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
335 p_bit_stream->p_byte =
336 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
340 p_bit_stream->fifo.i_available -= 32;
341 UnalignedRemoveBits( p_bit_stream );
344 # define RemoveBits32( p_bit_stream ) RemoveBits( p_bit_stream, 32 )
347 /*****************************************************************************
348 * GetBits : returns i_bits bits from the bit stream and removes them
349 * XXX: do not use for 32 bits, see GetBits32
350 *****************************************************************************/
351 static inline u32 GetBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
355 p_bit_stream->fifo.i_available -= i_bits;
357 if( p_bit_stream->fifo.i_available >= 0 )
359 i_result = p_bit_stream->fifo.buffer
360 >> (8 * sizeof(WORD_TYPE) - i_bits);
361 p_bit_stream->fifo.buffer <<= i_bits;
365 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
367 i_result = p_bit_stream->fifo.buffer
368 >> (8 * sizeof(WORD_TYPE) - i_bits);
369 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
370 p_bit_stream->p_byte =
371 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
372 i_result |= p_bit_stream->fifo.buffer
373 >> (8 * sizeof(WORD_TYPE)
374 + p_bit_stream->fifo.i_available);
375 p_bit_stream->fifo.buffer <<= ( -p_bit_stream->fifo.i_available );
376 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
380 return UnalignedGetBits( p_bit_stream, i_bits );
383 /*****************************************************************************
384 * GetSignedBits : returns i_bits bits from the bit stream and removes them,
385 * using signed arithmetic
386 * XXX: do not use for 32 bits
387 *****************************************************************************/
388 static inline s32 GetSignedBits( bit_stream_t * p_bit_stream,
389 unsigned int i_bits )
391 if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
395 p_bit_stream->fifo.i_available -= i_bits;
396 i_result = (WORD_SIGNED)p_bit_stream->fifo.buffer
397 >> (8 * sizeof(WORD_TYPE) - i_bits);
398 p_bit_stream->fifo.buffer <<= i_bits;
402 /* You can probably do something a little faster, but now I'm tired. */
403 return( (WORD_SIGNED)(GetBits( p_bit_stream, i_bits ) << (32 - i_bits))
407 /*****************************************************************************
408 * GetBits32 : returns 32 bits from the bit stream and removes them
409 *****************************************************************************/
410 #if (WORD_TYPE == u32)
411 static inline u32 GetBits32( bit_stream_t * p_bit_stream )
415 if( p_bit_stream->fifo.i_available == 32 )
417 p_bit_stream->fifo.i_available = 0;
418 i_result = p_bit_stream->fifo.buffer;
419 p_bit_stream->fifo.buffer = 0;
423 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
425 if( p_bit_stream->fifo.i_available )
427 i_result = p_bit_stream->fifo.buffer;
428 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
429 p_bit_stream->p_byte =
430 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
431 i_result |= p_bit_stream->fifo.buffer
432 >> (p_bit_stream->fifo.i_available);
433 p_bit_stream->fifo.buffer <<= (32 - p_bit_stream->fifo.i_available);
437 i_result = WORD_AT( p_bit_stream->p_byte );
438 p_bit_stream->p_byte =
439 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
443 p_bit_stream->fifo.i_available -= 32;
444 return UnalignedGetBits( p_bit_stream, 32 );
447 # define GetBits32( p_bit_stream ) GetBits( p_bit_stream, 32 )
450 /*****************************************************************************
451 * RealignBits : realigns the bit buffer on an 8-bit boundary
452 *****************************************************************************/
453 static inline void RealignBits( bit_stream_t * p_bit_stream )
455 p_bit_stream->fifo.buffer <<= (p_bit_stream->fifo.i_available & 0x7);
456 p_bit_stream->fifo.i_available &= ~0x7;
460 /*****************************************************************************
461 * GetChunk : reads a large chunk of data
462 *****************************************************************************
463 * The position in the stream must be byte-aligned, if unsure call
464 * RealignBits(). p_buffer must point to a buffer at least as big as i_buf_len
465 * otherwise your code will crash.
466 *****************************************************************************/
467 static inline void GetChunk( bit_stream_t * p_bit_stream,
468 byte_t * p_buffer, size_t i_buf_len )
470 ptrdiff_t i_available;
472 /* We need to take care because i_buf_len may be < 4. */
473 while( p_bit_stream->fifo.i_available > 0 && i_buf_len )
475 *p_buffer = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - 8);
478 p_bit_stream->fifo.buffer <<= 8;
479 p_bit_stream->fifo.i_available -= 8;
482 i_available = p_bit_stream->p_end - p_bit_stream->p_byte;
483 if( i_available >= (ptrdiff_t)i_buf_len )
485 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
486 p_bit_stream->p_byte, i_buf_len );
487 p_bit_stream->p_byte += i_buf_len;
493 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
494 p_bit_stream->p_byte, i_available );
495 p_bit_stream->p_byte = p_bit_stream->p_end;
496 p_buffer += i_available;
497 i_buf_len -= i_available;
498 BitstreamNextDataPacket( p_bit_stream );
499 if( p_bit_stream->p_decoder_fifo->b_die )
502 while( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
503 <= (ptrdiff_t)i_buf_len );
507 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
508 p_bit_stream->p_byte, i_buf_len );
509 p_bit_stream->p_byte += i_buf_len;
513 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
515 AlignWord( p_bit_stream );
521 * Communication interface between input and decoders
524 /*****************************************************************************
525 * Prototypes from input_dec.c
526 *****************************************************************************/
527 VLC_EXPORT( void, DecoderError, ( decoder_fifo_t * p_fifo ) );
529 #endif /* "input_ext-dec.h" */