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 1.72 2002/10/21 10:46:34 fenrir 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 VLC_EXPORT( int, input_NextPES, ( decoder_fifo_t *, pes_packet_t ** ) );
221 /*****************************************************************************
222 * AlignWord : fill in the bit buffer so that the byte pointer be aligned
223 * on a word boundary (XXX: there must be at least sizeof(WORD_TYPE) - 1
224 * empty bytes in the bit buffer)
225 *****************************************************************************/
226 static inline void AlignWord( bit_stream_t * p_bit_stream )
228 while( (ptrdiff_t)p_bit_stream->p_byte
229 & (sizeof(WORD_TYPE) - 1) )
231 if( p_bit_stream->p_byte < p_bit_stream->p_end )
233 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
234 << (8 * sizeof(WORD_TYPE) - 8
235 - p_bit_stream->fifo.i_available);
236 p_bit_stream->fifo.i_available += 8;
240 BitstreamNextDataPacket( p_bit_stream );
241 p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
242 << (8 * sizeof(WORD_TYPE) - 8
243 - p_bit_stream->fifo.i_available);
244 p_bit_stream->fifo.i_available += 8;
249 /*****************************************************************************
250 * ShowBits : return i_bits bits from the bit stream
251 *****************************************************************************/
252 static inline u32 ShowBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
254 if( p_bit_stream->fifo.i_available >= i_bits )
256 return( p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits) );
259 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
261 return( (p_bit_stream->fifo.buffer |
262 (WORD_AT( p_bit_stream->p_byte )
263 >> p_bit_stream->fifo.i_available))
264 >> (8 * sizeof(WORD_TYPE) - i_bits) );
267 return( UnalignedShowBits( p_bit_stream, i_bits ) );
270 /*****************************************************************************
271 * ShowSignedBits : return i_bits bits from the bit stream, using signed
273 *****************************************************************************/
274 static inline s32 ShowSignedBits( bit_stream_t * p_bit_stream,
275 unsigned int i_bits )
277 if( p_bit_stream->fifo.i_available >= i_bits )
279 return( (WORD_SIGNED)p_bit_stream->fifo.buffer
280 >> (8 * sizeof(WORD_TYPE) - i_bits) );
283 /* You can probably do something a little faster, but now I'm tired. */
284 return( (WORD_SIGNED)(ShowBits( p_bit_stream, i_bits ) << (32 - i_bits))
288 /*****************************************************************************
289 * RemoveBits : removes i_bits bits from the bit buffer
290 * XXX: do not use for 32 bits, see RemoveBits32
291 *****************************************************************************/
292 static inline void RemoveBits( bit_stream_t * p_bit_stream,
293 unsigned int i_bits )
295 p_bit_stream->fifo.i_available -= i_bits;
297 if( p_bit_stream->fifo.i_available >= 0 )
299 p_bit_stream->fifo.buffer <<= i_bits;
303 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
305 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
306 << ( -p_bit_stream->fifo.i_available );
307 p_bit_stream->p_byte =
308 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
309 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
313 UnalignedRemoveBits( p_bit_stream );
316 /*****************************************************************************
317 * RemoveBits32 : removes 32 bits from the bit buffer (and as a side effect,
319 *****************************************************************************/
320 #if (WORD_TYPE == u32)
321 static inline void RemoveBits32( bit_stream_t * p_bit_stream )
323 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
325 if( p_bit_stream->fifo.i_available )
327 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
328 << (32 - p_bit_stream->fifo.i_available);
329 p_bit_stream->p_byte =
330 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
334 p_bit_stream->p_byte =
335 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
339 p_bit_stream->fifo.i_available -= 32;
340 UnalignedRemoveBits( p_bit_stream );
343 # define RemoveBits32( p_bit_stream ) RemoveBits( p_bit_stream, 32 )
346 /*****************************************************************************
347 * GetBits : returns i_bits bits from the bit stream and removes them
348 * XXX: do not use for 32 bits, see GetBits32
349 *****************************************************************************/
350 static inline u32 GetBits( bit_stream_t * p_bit_stream, unsigned int i_bits )
354 p_bit_stream->fifo.i_available -= i_bits;
356 if( p_bit_stream->fifo.i_available >= 0 )
358 i_result = p_bit_stream->fifo.buffer
359 >> (8 * sizeof(WORD_TYPE) - i_bits);
360 p_bit_stream->fifo.buffer <<= i_bits;
364 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
366 i_result = p_bit_stream->fifo.buffer
367 >> (8 * sizeof(WORD_TYPE) - i_bits);
368 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
369 p_bit_stream->p_byte =
370 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
371 i_result |= p_bit_stream->fifo.buffer
372 >> (8 * sizeof(WORD_TYPE)
373 + p_bit_stream->fifo.i_available);
374 p_bit_stream->fifo.buffer <<= ( -p_bit_stream->fifo.i_available );
375 p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
379 return UnalignedGetBits( p_bit_stream, i_bits );
382 /*****************************************************************************
383 * GetSignedBits : returns i_bits bits from the bit stream and removes them,
384 * using signed arithmetic
385 * XXX: do not use for 32 bits
386 *****************************************************************************/
387 static inline s32 GetSignedBits( bit_stream_t * p_bit_stream,
388 unsigned int i_bits )
390 if( p_bit_stream->fifo.i_available >= i_bits )
394 p_bit_stream->fifo.i_available -= i_bits;
395 i_result = (WORD_SIGNED)p_bit_stream->fifo.buffer
396 >> (8 * sizeof(WORD_TYPE) - i_bits);
397 p_bit_stream->fifo.buffer <<= i_bits;
401 /* You can probably do something a little faster, but now I'm tired. */
402 return( (WORD_SIGNED)(GetBits( p_bit_stream, i_bits ) << (32 - i_bits))
406 /*****************************************************************************
407 * GetBits32 : returns 32 bits from the bit stream and removes them
408 *****************************************************************************/
409 #if (WORD_TYPE == u32)
410 static inline u32 GetBits32( bit_stream_t * p_bit_stream )
414 if( p_bit_stream->fifo.i_available == 32 )
416 p_bit_stream->fifo.i_available = 0;
417 i_result = p_bit_stream->fifo.buffer;
418 p_bit_stream->fifo.buffer = 0;
422 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
424 if( p_bit_stream->fifo.i_available )
426 i_result = p_bit_stream->fifo.buffer;
427 p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
428 p_bit_stream->p_byte =
429 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
430 i_result |= p_bit_stream->fifo.buffer
431 >> (p_bit_stream->fifo.i_available);
432 p_bit_stream->fifo.buffer <<= (32 - p_bit_stream->fifo.i_available);
436 i_result = WORD_AT( p_bit_stream->p_byte );
437 p_bit_stream->p_byte =
438 (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
442 p_bit_stream->fifo.i_available -= 32;
443 return UnalignedGetBits( p_bit_stream, 32 );
446 # define GetBits32( p_bit_stream ) GetBits( p_bit_stream, 32 )
449 /*****************************************************************************
450 * RealignBits : realigns the bit buffer on an 8-bit boundary
451 *****************************************************************************/
452 static inline void RealignBits( bit_stream_t * p_bit_stream )
454 p_bit_stream->fifo.buffer <<= (p_bit_stream->fifo.i_available & 0x7);
455 p_bit_stream->fifo.i_available &= ~0x7;
459 /*****************************************************************************
460 * GetChunk : reads a large chunk of data
461 *****************************************************************************
462 * The position in the stream must be byte-aligned, if unsure call
463 * RealignBits(). p_buffer must point to a buffer at least as big as i_buf_len
464 * otherwise your code will crash.
465 *****************************************************************************/
466 static inline void GetChunk( bit_stream_t * p_bit_stream,
467 byte_t * p_buffer, size_t i_buf_len )
469 ptrdiff_t i_available;
471 /* We need to take care because i_buf_len may be < 4. */
472 while( p_bit_stream->fifo.i_available > 0 && i_buf_len )
474 *p_buffer = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - 8);
477 p_bit_stream->fifo.buffer <<= 8;
478 p_bit_stream->fifo.i_available -= 8;
481 if( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
484 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
485 p_bit_stream->p_byte, i_buf_len );
486 p_bit_stream->p_byte += i_buf_len;
492 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
493 p_bit_stream->p_byte, i_available );
494 p_bit_stream->p_byte = p_bit_stream->p_end;
495 p_buffer += i_available;
496 i_buf_len -= i_available;
497 BitstreamNextDataPacket( p_bit_stream );
498 if( p_bit_stream->p_decoder_fifo->b_die )
501 while( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
506 p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
507 p_bit_stream->p_byte, i_buf_len );
508 p_bit_stream->p_byte += i_buf_len;
512 if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
514 AlignWord( p_bit_stream );
520 * Communication interface between input and decoders
523 /*****************************************************************************
524 * Prototypes from input_dec.c
525 *****************************************************************************/
526 VLC_EXPORT( void, DecoderError, ( decoder_fifo_t * p_fifo ) );
528 #endif /* "input_ext-dec.h" */