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 1.71 2002/08/30 22:22:24 massiot 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 data packet (in the current PES packet of the PES stream) */
171 data_packet_t * p_data;
172 /* Pointer to the next byte that is to be read (in the current packet) */
174 /* Pointer to the last byte that is to be read (in the current packet */
176 /* Temporary buffer in case we're not aligned when changing data packets */
177 WORD_TYPE i_showbits_buffer;
178 data_packet_t showbits_data;
181 /*****************************************************************************
182 * Inline functions used by the decoders to read bit_stream_t
183 *****************************************************************************/
186 * DISCUSSION : How to use the bit_stream structures
188 * sizeof(WORD_TYPE) (usually 32) bits are read at the same time, thus
189 * minimizing the number of p_byte changes.
190 * Bits are read via GetBits() or ShowBits.
192 * XXX : Be aware that if, in the forthcoming functions, i_bits > 24,
193 * the data have to be already aligned on an 8-bit boundary, or wrong
194 * results will be returned. Use RealignBits() if unsure.
197 #if (WORD_TYPE == u32)
198 # define WORD_AT U32_AT
199 # define WORD_SIGNED s32
200 #elif (WORD_TYPE == u64)
201 # define WORD_AT U64_AT
202 # define WORD_SIGNED s64
204 # error Unsupported WORD_TYPE
207 /*****************************************************************************
208 * Prototypes from input_ext-dec.c
209 *****************************************************************************/
210 VLC_EXPORT( void, InitBitstream, ( bit_stream_t *, decoder_fifo_t *, void ( * )( bit_stream_t *, vlc_bool_t ), void * p_callback_arg ) );
211 VLC_EXPORT( vlc_bool_t, NextDataPacket, ( decoder_fifo_t *, data_packet_t ** ) );
212 VLC_EXPORT( void, BitstreamNextDataPacket, ( bit_stream_t * ) );
213 VLC_EXPORT( u32, UnalignedShowBits, ( bit_stream_t *, unsigned int ) );
214 VLC_EXPORT( void, UnalignedRemoveBits, ( bit_stream_t * ) );
215 VLC_EXPORT( u32, UnalignedGetBits, ( bit_stream_t *, unsigned int ) );
216 VLC_EXPORT( void, CurrentPTS, ( bit_stream_t *, mtime_t *, mtime_t * ) );
217 VLC_EXPORT( void, NextPTS, ( bit_stream_t *, mtime_t *, mtime_t * ) );
219 /*****************************************************************************
220 * AlignWord : fill in the bit buffer so that the byte pointer be aligned
221 * on a word boundary (XXX: there must be at least sizeof(WORD_TYPE) - 1
222 * empty bytes in the bit buffer)
223 *****************************************************************************/
224 static inline void AlignWord( bit_stream_t * p_bit_stream )
226 while( (ptrdiff_t)p_bit_stream->p_byte
227 & (sizeof(WORD_TYPE) - 1) )
229 if( p_bit_stream->p_byte < p_bit_stream->p_end )
231 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
232 << (8 * sizeof(WORD_TYPE) - 8
233 - p_bit_stream->fifo.i_available);
234 p_bit_stream->fifo.i_available += 8;
238 BitstreamNextDataPacket( p_bit_stream );
239 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
240 << (8 * sizeof(WORD_TYPE) - 8
241 - p_bit_stream->fifo.i_available);
242 p_bit_stream->fifo.i_available += 8;
247 /*****************************************************************************
248 * ShowBits : return i_bits bits from the bit stream
249 *****************************************************************************/
250 static inline u32 ShowBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
252 if( p_bit_stream->fifo.i_available >= i_bits )
254 return( p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits) );
257 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
259 return( (p_bit_stream->fifo.buffer |
260 (WORD_AT( p_bit_stream->p_byte )
261 >> p_bit_stream->fifo.i_available))
262 >> (8 * sizeof(WORD_TYPE) - i_bits) );
265 return( UnalignedShowBits( p_bit_stream, i_bits ) );
268 /*****************************************************************************
269 * ShowSignedBits : return i_bits bits from the bit stream, using signed
271 *****************************************************************************/
272 static inline s32 ShowSignedBits( bit_stream_t * p_bit_stream,
273 unsigned int i_bits )
275 if( p_bit_stream->fifo.i_available >= i_bits )
277 return( (WORD_SIGNED)p_bit_stream->fifo.buffer
278 >> (8 * sizeof(WORD_TYPE) - i_bits) );
281 /* You can probably do something a little faster, but now I'm tired. */
282 return( (WORD_SIGNED)(ShowBits( p_bit_stream, i_bits ) << (32 - i_bits))
286 /*****************************************************************************
287 * RemoveBits : removes i_bits bits from the bit buffer
288 * XXX: do not use for 32 bits, see RemoveBits32
289 *****************************************************************************/
290 static inline void RemoveBits( bit_stream_t * p_bit_stream,
291 unsigned int i_bits )
293 p_bit_stream->fifo.i_available -= i_bits;
295 if( p_bit_stream->fifo.i_available >= 0 )
297 p_bit_stream->fifo.buffer <<= i_bits;
301 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
303 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
304 << ( -p_bit_stream->fifo.i_available );
305 p_bit_stream->p_byte =
306 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
307 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
311 UnalignedRemoveBits( p_bit_stream );
314 /*****************************************************************************
315 * RemoveBits32 : removes 32 bits from the bit buffer (and as a side effect,
317 *****************************************************************************/
318 #if (WORD_TYPE == u32)
319 static inline void RemoveBits32( bit_stream_t * p_bit_stream )
321 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
323 if( p_bit_stream->fifo.i_available )
325 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
326 << (32 - p_bit_stream->fifo.i_available);
327 p_bit_stream->p_byte =
328 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
332 p_bit_stream->p_byte =
333 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
337 p_bit_stream->fifo.i_available -= 32;
338 UnalignedRemoveBits( p_bit_stream );
341 # define RemoveBits32( p_bit_stream ) RemoveBits( p_bit_stream, 32 )
344 /*****************************************************************************
345 * GetBits : returns i_bits bits from the bit stream and removes them
346 * XXX: do not use for 32 bits, see GetBits32
347 *****************************************************************************/
348 static inline u32 GetBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
352 p_bit_stream->fifo.i_available -= i_bits;
354 if( p_bit_stream->fifo.i_available >= 0 )
356 i_result = p_bit_stream->fifo.buffer
357 >> (8 * sizeof(WORD_TYPE) - i_bits);
358 p_bit_stream->fifo.buffer <<= i_bits;
362 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
364 i_result = p_bit_stream->fifo.buffer
365 >> (8 * sizeof(WORD_TYPE) - i_bits);
366 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
367 p_bit_stream->p_byte =
368 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
369 i_result |= p_bit_stream->fifo.buffer
370 >> (8 * sizeof(WORD_TYPE)
371 + p_bit_stream->fifo.i_available);
372 p_bit_stream->fifo.buffer <<= ( -p_bit_stream->fifo.i_available );
373 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
377 return UnalignedGetBits( p_bit_stream, i_bits );
380 /*****************************************************************************
381 * GetSignedBits : returns i_bits bits from the bit stream and removes them,
382 * using signed arithmetic
383 * XXX: do not use for 32 bits
384 *****************************************************************************/
385 static inline s32 GetSignedBits( bit_stream_t * p_bit_stream,
386 unsigned int i_bits )
388 if( p_bit_stream->fifo.i_available >= i_bits )
392 p_bit_stream->fifo.i_available -= i_bits;
393 i_result = (WORD_SIGNED)p_bit_stream->fifo.buffer
394 >> (8 * sizeof(WORD_TYPE) - i_bits);
395 p_bit_stream->fifo.buffer <<= i_bits;
399 /* You can probably do something a little faster, but now I'm tired. */
400 return( (WORD_SIGNED)(GetBits( p_bit_stream, i_bits ) << (32 - i_bits))
404 /*****************************************************************************
405 * GetBits32 : returns 32 bits from the bit stream and removes them
406 *****************************************************************************/
407 #if (WORD_TYPE == u32)
408 static inline u32 GetBits32( bit_stream_t * p_bit_stream )
412 if( p_bit_stream->fifo.i_available == 32 )
414 p_bit_stream->fifo.i_available = 0;
415 i_result = p_bit_stream->fifo.buffer;
416 p_bit_stream->fifo.buffer = 0;
420 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
422 if( p_bit_stream->fifo.i_available )
424 i_result = p_bit_stream->fifo.buffer;
425 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
426 p_bit_stream->p_byte =
427 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
428 i_result |= p_bit_stream->fifo.buffer
429 >> (p_bit_stream->fifo.i_available);
430 p_bit_stream->fifo.buffer <<= (32 - p_bit_stream->fifo.i_available);
434 i_result = WORD_AT( p_bit_stream->p_byte );
435 p_bit_stream->p_byte =
436 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
440 p_bit_stream->fifo.i_available -= 32;
441 return UnalignedGetBits( p_bit_stream, 32 );
444 # define GetBits32( p_bit_stream ) GetBits( p_bit_stream, 32 )
447 /*****************************************************************************
448 * RealignBits : realigns the bit buffer on an 8-bit boundary
449 *****************************************************************************/
450 static inline void RealignBits( bit_stream_t * p_bit_stream )
452 p_bit_stream->fifo.buffer <<= (p_bit_stream->fifo.i_available & 0x7);
453 p_bit_stream->fifo.i_available &= ~0x7;
457 /*****************************************************************************
458 * GetChunk : reads a large chunk of data
459 *****************************************************************************
460 * The position in the stream must be byte-aligned, if unsure call
461 * RealignBits(). p_buffer must point to a buffer at least as big as i_buf_len
462 * otherwise your code will crash.
463 *****************************************************************************/
464 static inline void GetChunk( bit_stream_t * p_bit_stream,
465 byte_t * p_buffer, size_t i_buf_len )
467 ptrdiff_t i_available;
469 /* We need to take care because i_buf_len may be < 4. */
470 while( p_bit_stream->fifo.i_available > 0 && i_buf_len )
472 *p_buffer = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - 8);
475 p_bit_stream->fifo.buffer <<= 8;
476 p_bit_stream->fifo.i_available -= 8;
479 if( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
482 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
483 p_bit_stream->p_byte, i_buf_len );
484 p_bit_stream->p_byte += i_buf_len;
490 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
491 p_bit_stream->p_byte, i_available );
492 p_bit_stream->p_byte = p_bit_stream->p_end;
493 p_buffer += i_available;
494 i_buf_len -= i_available;
495 BitstreamNextDataPacket( p_bit_stream );
496 if( p_bit_stream->p_decoder_fifo->b_die )
499 while( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
504 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
505 p_bit_stream->p_byte, i_buf_len );
506 p_bit_stream->p_byte += i_buf_len;
510 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
512 AlignWord( p_bit_stream );
518 * Communication interface between input and decoders
521 /*****************************************************************************
522 * Prototypes from input_dec.c
523 *****************************************************************************/
524 VLC_EXPORT( void, DecoderError, ( decoder_fifo_t * p_fifo ) );
526 #endif /* "input_ext-dec.h" */