]> git.sesse.net Git - vlc/blobdiff - include/input_ext-dec.h
* ALL: Introduction of a new api for decoders.
[vlc] / include / input_ext-dec.h
index 33ec47134af41be94e5cbb9de805c1cef55be310..12c8ceadb4e046130f476317c3cfe7a660a7c47d 100644 (file)
@@ -1,10 +1,11 @@
 /*****************************************************************************
  * input_ext-dec.h: structures exported to the VideoLAN decoders
  *****************************************************************************
- * Copyright (C) 1999, 2000 VideoLAN
- * $Id: input_ext-dec.h,v 1.7 2000/12/27 18:35:45 massiot Exp $
+ * Copyright (C) 1999-2001 VideoLAN
+ * $Id: input_ext-dec.h,v 1.80 2003/09/02 20:19:25 gbazin Exp $
  *
- * Authors:
+ * Authors: Christophe Massiot <massiot@via.ecp.fr>
+ *          Michel Kaempf <maxx@via.ecp.fr>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,6 +22,9 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  *****************************************************************************/
 
+#ifndef _VLC_INPUT_EXT_DEC_H
+#define _VLC_INPUT_EXT_DEC_H 1
+
 /* Structures exported to the decoders */
 
 /*****************************************************************************
  *****************************************************************************
  * Describe a data packet.
  *****************************************************************************/
-typedef struct data_packet_s
+struct data_packet_t
 {
-    /* Nothing before this line, the code relies on that */
-    byte_t *                p_buffer;                     /* raw data packet */
+    /* Used to chain the packets that carry data for a same PES or PSI */
+    data_packet_t *  p_next;
 
-    /* Decoders information */
-    byte_t *                p_payload_start;
-                                  /* start of the PES payload in this packet */
-    byte_t *                p_payload_end;                    /* guess ? :-) */
-    boolean_t               b_discard_payload;  /* is the packet messed up ? */
+    /* start of the PS or TS packet */
+    byte_t *         p_demux_start;
+    /* start of the PES payload in this packet */
+    byte_t *         p_payload_start;
+    byte_t *         p_payload_end; /* guess ? :-) */
+    /* is the packet messed up ? */
+    vlc_bool_t       b_discard_payload;
 
-    /* Used to chain the TS packets that carry data for a same PES or PSI */
-    struct data_packet_s *  p_next;
-} data_packet_t;
+    /* pointer to the real data */
+    data_buffer_t *  p_buffer;
+};
 
 /*****************************************************************************
  * pes_packet_t
@@ -49,63 +55,86 @@ typedef struct data_packet_s
  * Describes an PES packet, with its properties, and pointers to the TS packets
  * containing it.
  *****************************************************************************/
-typedef struct pes_packet_s
+struct pes_packet_t
 {
+    /* Chained list to the next PES packet (depending on the context) */
+    pes_packet_t *  p_next;
+
     /* PES properties */
-    boolean_t               b_messed_up;  /* At least one of the data packets
-                                           * has a questionable content      */
-    boolean_t               b_data_alignment;  /* used to find the beginning of
-                                                * a video or audio unit      */
-    boolean_t               b_discontinuity; /* This packet doesn't follow the
-                                              * previous one                 */
+    vlc_bool_t      b_data_alignment;          /* used to find the beginning of
+                                                * a video or audio unit */
+    vlc_bool_t      b_discontinuity;          /* This packet doesn't follow the
+                                               * previous one */
 
-    mtime_t                 i_pts;/* the PTS for this packet (zero if unset) */
-    mtime_t                 i_dts;/* the DTS for this packet (zero if unset) */
+    mtime_t         i_pts;            /* PTS for this packet (zero if unset) */
+    mtime_t         i_dts;            /* DTS for this packet (zero if unset) */
+    int             i_rate;   /* current reading pace (see stream_control.h) */
 
-    int                     i_pes_size;    /* size of the current PES packet */
+    unsigned int    i_pes_size;            /* size of the current PES packet */
 
-    /* Pointers to packets (packets are then linked by the p_prev and
-       p_next fields of the data_packet_t struct) */
-    data_packet_t *         p_first;      /* The first packet containing this
+    /* Chained list to packets */
+    data_packet_t * p_first;              /* The first packet contained by this
                                            * PES (used by decoders). */
-} pes_packet_t;
+    data_packet_t * p_last;            /* The last packet contained by this
+                                        * PES (used by the buffer allocator) */
+    unsigned int    i_nb_data; /* Number of data packets in the chained list */
+};
 
 /*****************************************************************************
  * decoder_fifo_t
  *****************************************************************************
  * This rotative FIFO contains PES packets that are to be decoded.
  *****************************************************************************/
-typedef struct decoder_fifo_s
+struct decoder_fifo_t
 {
+    VLC_COMMON_MEMBERS
+
     /* Thread structures */
-    vlc_mutex_t             data_lock;                     /* fifo data lock */
-    vlc_cond_t              data_wait;     /* fifo data conditional variable */
+    vlc_mutex_t         data_lock;                         /* fifo data lock */
+    vlc_cond_t          data_wait;         /* fifo data conditional variable */
 
     /* Data */
-    pes_packet_t *          buffer[FIFO_SIZE + 1];
-    int                     i_start;
-    int                     i_end;
+    pes_packet_t *      p_first;
+    pes_packet_t **     pp_last;
+    int                 i_depth;       /* number of PES packets in the stack */
 
     /* Communication interface between input and decoders */
-    boolean_t               b_die;          /* the decoder should return now */
-    boolean_t               b_error;      /* the decoder is in an error loop */
-    void *                  p_packets_mgt;   /* packets management services
-                                              * data (netlist...)            */
-    void                 (* pf_delete_pes)( void *, pes_packet_t * );
-                                     /* function to use when releasing a PES */
-} decoder_fifo_t;
-
-/* Macros to manage a decoder_fifo_t structure. Please remember to take
- * data_lock before using them. */
-#define DECODER_FIFO_ISEMPTY( fifo )  ( (fifo).i_start == (fifo).i_end )
-#define DECODER_FIFO_ISFULL( fifo )   ( ( ((fifo).i_end + 1 - (fifo).i_start)\
-                                          & FIFO_SIZE ) == 0 )
-#define DECODER_FIFO_START( fifo )    ( (fifo).buffer[ (fifo).i_start ] )
-#define DECODER_FIFO_INCSTART( fifo ) ( (fifo).i_start = ((fifo).i_start + 1)\
-                                                         & FIFO_SIZE )
-#define DECODER_FIFO_END( fifo )      ( (fifo).buffer[ (fifo).i_end ] )
-#define DECODER_FIFO_INCEND( fifo )   ( (fifo).i_end = ((fifo).i_end + 1) \
-                                                       & FIFO_SIZE )
+    input_buffers_t    *p_packets_mgt;   /* packets management services data */
+
+    /* Standard pointers given to the decoders as a toolbox. */
+    uint16_t            i_id;
+    vlc_fourcc_t        i_fourcc;
+    es_sys_t *          p_demux_data;
+    stream_ctrl_t *     p_stream_ctrl;
+    sout_instance_t *   p_sout;
+    void *              p_waveformatex;
+    void *              p_bitmapinfoheader;
+
+    decoder_t *         p_dec;
+};
+
+/*****************************************************************************
+ * decoder_t
+ *****************************************************************************
+ * The decoder descriptor.
+ *****************************************************************************/
+struct decoder_t
+{
+    VLC_COMMON_MEMBERS
+
+    /* Module properties */
+    module_t *          p_module;
+    decoder_sys_t *     p_sys;
+    int                 ( * pf_init )  ( decoder_t * );
+    int                 ( * pf_decode )( decoder_t *, block_t * );
+    int                 ( * pf_end )   ( decoder_t * );
+
+    /* Input properties */
+    decoder_fifo_t *    p_fifo;                /* stores the PES stream data */
+
+    /* Tmp field for old decoder api */
+    int                 ( * pf_run ) ( decoder_fifo_t * );
+};
 
 /*****************************************************************************
  * bit_fifo_t : bit fifo descriptor
@@ -113,9 +142,9 @@ typedef struct decoder_fifo_s
  * This type describes a bit fifo used to store bits while working with the
  * input stream at the bit level.
  *****************************************************************************/
-typedef u32         WORD_TYPE;        /* only u32 is supported at the moment */
+typedef uint32_t    WORD_TYPE;
 
-typedef struct bit_fifo_s
+typedef struct bit_fifo_t
 {
     /* This unsigned integer allows us to work at the bit level. This buffer
      * can contain 32 bits, and the used space can be found on the MSb's side
@@ -133,181 +162,162 @@ typedef struct bit_fifo_s
  * This type, based on a PES stream, includes all the structures needed to
  * handle the input stream like a bit stream.
  *****************************************************************************/
-typedef struct bit_stream_s
+struct bit_stream_t
 {
+    /*
+     * Bit structures
+     */
+    bit_fifo_t       fifo;
+
     /*
      * Input structures
      */
     /* The decoder fifo contains the data of the PES stream */
-    decoder_fifo_t *        p_decoder_fifo;
+    decoder_fifo_t * p_decoder_fifo;
+
+    /* Callback to the decoder used when changing data packets ; set
+     * to NULL if your decoder doesn't need it. */
+    void          (* pf_bitstream_callback)( bit_stream_t *, vlc_bool_t );
+    /* Optional argument to the callback */
+    void *           p_callback_arg;
 
-    /* Function to jump to the next data packet */
-    void                 (* pf_next_data_packet)( struct bit_stream_s * );
+    /*
+     * PTS retrieval
+     */
+    mtime_t          i_pts, i_dts;
+    byte_t *         p_pts_validity;
 
     /*
      * Byte structures
      */
-    /* Current data packet (in the current PES packet of the PES stream) */
+    /* Current PES packet (extracted from the PES stream) */
+    pes_packet_t *          p_pes;
+    /* Current data packet (in the current PES packet) */
     data_packet_t *         p_data;
-    /* Pointer to the next byte that is to be read (in the current TS packet) */
+    /* Pointer to the next byte that is to be read (in the current packet) */
     byte_t *                p_byte;
-    /* Pointer to the last byte that is to be read (in the current TS packet */
+    /* Pointer to the last byte that is to be read (in the current packet */
     byte_t *                p_end;
-
-    /*
-     * Bit structures
-     */
-    bit_fifo_t              fifo;
-} bit_stream_t;
+    /* Temporary buffer in case we're not aligned when changing data packets */
+    WORD_TYPE               i_showbits_buffer;
+    data_packet_t           showbits_data;
+};
 
 /*****************************************************************************
  * Inline functions used by the decoders to read bit_stream_t
  *****************************************************************************/
 
 /*
- * Philosophy of the first implementation : the bit buffer is first filled by
- * NeedBits, then the buffer can be read via p_bit_stream->fifo.buffer, and
- * unnecessary bits are dumped with a DumpBits() call.
+ * DISCUSSION : How to use the bit_stream structures
+ *
+ * sizeof(WORD_TYPE) (usually 32) bits are read at the same time, thus
+ * minimizing the number of p_byte changes.
+ * Bits are read via GetBits() or ShowBits.
+ *
+ * XXX : Be aware that if, in the forthcoming functions, i_bits > 24,
+ * the data have to be already aligned on an 8-bit boundary, or wrong
+ * results will be returned. Use RealignBits() if unsure.
  */
 
+#if (WORD_TYPE == uint32_t)
+#   define WORD_AT      U32_AT
+#   define WORD_SIGNED  int32_t
+#elif (WORD_TYPE == uint64_t)
+#   define WORD_AT      U64_AT
+#   define WORD_SIGNED  int64_t
+#else
+#   error Unsupported WORD_TYPE
+#endif
+
 /*****************************************************************************
- * GetByte : reads the next byte in the input stream
+ * Prototypes from input_ext-dec.c
  *****************************************************************************/
-static __inline__ byte_t GetByte( bit_stream_t * p_bit_stream )
-{
-    /* Are there some bytes left in the current data packet ? */
-    /* could change this test to have a if (! (bytes--)) instead */
-    if ( p_bit_stream->p_byte >= p_bit_stream->p_end )
-    {
-        /* no, switch to next data packet */
-        p_bit_stream->pf_next_data_packet( p_bit_stream );
-    }
-
-    return( *(p_bit_stream->p_byte++) );
-}
+VLC_EXPORT( void, input_ExtractPES,        ( decoder_fifo_t *, pes_packet_t ** ) );
+VLC_EXPORT( void, input_DeletePES,         ( input_buffers_t *, pes_packet_t * ) );
+VLC_EXPORT( int, InitBitstream, ( bit_stream_t *, decoder_fifo_t *, void ( * )( bit_stream_t *, vlc_bool_t ), void * p_callback_arg ) );
+VLC_EXPORT( vlc_bool_t, NextDataPacket,    ( decoder_fifo_t *, bit_stream_t * ) );
+VLC_EXPORT( void, BitstreamNextDataPacket, ( bit_stream_t * ) );
+VLC_EXPORT( uint32_t, UnalignedShowBits,   ( bit_stream_t *, unsigned int ) );
+VLC_EXPORT( void, UnalignedRemoveBits,     ( bit_stream_t * ) );
+VLC_EXPORT( uint32_t, UnalignedGetBits,    ( bit_stream_t *, unsigned int ) );
+VLC_EXPORT( void, CloseBitstream,          ( bit_stream_t * ) );
+VLC_EXPORT( void, CurrentPTS,              ( bit_stream_t *, mtime_t *, mtime_t * ) );
+VLC_EXPORT( void, NextPTS,                 ( bit_stream_t *, mtime_t *, mtime_t * ) );
 
 /*****************************************************************************
- * NeedBits : reads i_bits new bits in the bit stream and stores them in the
- *            bit buffer
- *****************************************************************************
- * - i_bits must be less or equal 32 !
- * - There is something important to notice with that function : if the number
- * of bits available in the bit buffer when calling NeedBits() is greater than
- * 24 (i_available > 24) but less than the number of needed bits
- * (i_available < i_bits), the byte returned by GetByte() will be shifted with
- * a negative value and the number of bits available in the bit buffer will be
- * set to more than 32 !
+ * AlignWord : fill in the bit buffer so that the byte pointer be aligned
+ * on a word boundary (XXX: there must be at least sizeof(WORD_TYPE) - 1
+ * empty bytes in the bit buffer)
  *****************************************************************************/
-static __inline__ void NeedBits( bit_stream_t * p_bit_stream, int i_bits )
+static inline void AlignWord( bit_stream_t * p_bit_stream )
 {
-    while ( p_bit_stream->fifo.i_available < i_bits )
+    while( (ptrdiff_t)p_bit_stream->p_byte
+             & (sizeof(WORD_TYPE) - 1) )
     {
-        p_bit_stream->fifo.buffer |= ((WORD_TYPE)GetByte( p_bit_stream ))
-                                     << (sizeof(WORD_TYPE) - 8
-                                            - p_bit_stream->fifo.i_available);
-        p_bit_stream->fifo.i_available += 8;
+        if( p_bit_stream->p_byte < p_bit_stream->p_end )
+        {
+            p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
+                << (8 * sizeof(WORD_TYPE) - 8
+                     - p_bit_stream->fifo.i_available);
+            p_bit_stream->fifo.i_available += 8;
+        }
+        else
+        {
+            BitstreamNextDataPacket( p_bit_stream );
+            p_bit_stream->fifo.buffer |= *(p_bit_stream->p_byte++)
+                << (8 * sizeof(WORD_TYPE) - 8
+                     - p_bit_stream->fifo.i_available);
+            p_bit_stream->fifo.i_available += 8;
+        }
     }
 }
 
-/*****************************************************************************
- * DumpBits : removes i_bits bits from the bit buffer
- *****************************************************************************
- * - i_bits <= i_available
- * - i_bits < 32 (because (u32 << 32) <=> (u32 = u32))
- *****************************************************************************/
-static __inline__ void DumpBits( bit_stream_t * p_bit_stream, int i_bits )
-{
-    p_bit_stream->fifo.buffer <<= i_bits;
-    p_bit_stream->fifo.i_available -= i_bits;
-}
-
-
-/*
- * Philosophy of the second implementation : WORD_LENGTH (usually 32) bits
- * are read at the same time, thus minimizing the number of p_byte changes.
- * Bits are read via GetBits() or ShowBits. This is slightly faster. Be
- * aware that if, in the forthcoming functions, i_bits > 24, the data have to
- * be already aligned on an 8-bit boundary, or wrong results will be
- * returned.
- */
-
-#if (WORD_TYPE != u32)
-#   error Not supported word
-#endif
-
-/*
- * This is stolen from the livid source who stole it from the kernel
- * FIXME: The macro swab32 for little endian machines does
- *        not seem to work correctly
- */
-
-#if defined(SYS_BEOS)
-#   define swab32(x) B_BENDIAN_TO_HOST_INT32(x)
-#else
-#   if __BYTE_ORDER == __BIG_ENDIAN
-#       define swab32(x) (x)
-#   else
-#       if defined (__i386__)
-static __inline__ const u32 __i386_swab32( u32 x )
-{
-    __asm__("bswap %0" : "=r" (x) : "0" (x));
-    return x;
-}
-#           define swab32(x) __i386_swab32(x)
-#       else
-#           define swab32(x)                                                 \
-            ( ( (u32)(((u8*)&x)[0]) << 24 ) | ( (u32)(((u8*)&x)[1]) << 16 ) |\
-              ( (u32)(((u8*)&x)[2]) << 8 )  | ( (u32)(((u8*)&x)[3])) )
-#       endif
-#   endif
-#endif
-
 /*****************************************************************************
  * ShowBits : return i_bits bits from the bit stream
  *****************************************************************************/
-static __inline__ WORD_TYPE ShowWord( bit_stream_t * p_bit_stream )
+static inline uint32_t ShowBits( bit_stream_t * p_bit_stream,
+                                 unsigned int i_bits )
 {
-    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
     {
-        return( swab32( *((WORD_TYPE *)p_bit_stream->p_byte) ) );
+        return( p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits) );
     }
 
-    p_bit_stream->pf_next_data_packet( p_bit_stream );
-    return( swab32( *((WORD_TYPE *)p_bit_stream->p_byte) ) );
-}
-
-static __inline__ WORD_TYPE ShowBits( bit_stream_t * p_bit_stream, int i_bits )
-{
-    if( p_bit_stream->fifo.i_available >= i_bits )
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
     {
-        return( p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits) );
+        return( (p_bit_stream->fifo.buffer |
+                    (WORD_AT( p_bit_stream->p_byte )
+                        >> p_bit_stream->fifo.i_available))
+                    >> (8 * sizeof(WORD_TYPE) - i_bits) );
     }
 
-    return( (p_bit_stream->fifo.buffer |
-            (ShowWord( p_bit_stream ) >> p_bit_stream->fifo.i_available))
-                    >> (8 * sizeof(WORD_TYPE) - i_bits) );
+    return( UnalignedShowBits( p_bit_stream, i_bits ) );
 }
 
 /*****************************************************************************
- * GetWord : returns the next word to be read
+ * ShowSignedBits : return i_bits bits from the bit stream, using signed
+ *                  arithmetic
  *****************************************************************************/
-static __inline__ WORD_TYPE GetWord( bit_stream_t * p_bit_stream )
+static inline int32_t ShowSignedBits( bit_stream_t * p_bit_stream,
+                                      unsigned int i_bits )
 {
-    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
     {
-        return( swab32( *(((WORD_TYPE *)p_bit_stream->p_byte)++) ) );
-    }
-    else
-    {
-        p_bit_stream->pf_next_data_packet( p_bit_stream );
-        return( swab32( *(((WORD_TYPE *)p_bit_stream->p_byte)++) ) );
+        return( (WORD_SIGNED)p_bit_stream->fifo.buffer
+                    >> (8 * sizeof(WORD_TYPE) - i_bits) );
     }
+
+    /* You can probably do something a little faster, but now I'm tired. */
+    return( (WORD_SIGNED)(ShowBits( p_bit_stream, i_bits ) << (32 - i_bits))
+             >> (32 - i_bits) );
 }
 
 /*****************************************************************************
  * RemoveBits : removes i_bits bits from the bit buffer
+ *              XXX: do not use for 32 bits, see RemoveBits32
  *****************************************************************************/
-static __inline__ void RemoveBits( bit_stream_t * p_bit_stream, int i_bits )
+static inline void RemoveBits( bit_stream_t * p_bit_stream,
+                               unsigned int i_bits )
 {
     p_bit_stream->fifo.i_available -= i_bits;
 
@@ -316,117 +326,221 @@ static __inline__ void RemoveBits( bit_stream_t * p_bit_stream, int i_bits )
         p_bit_stream->fifo.buffer <<= i_bits;
         return;
     }
-    p_bit_stream->fifo.buffer = GetWord( p_bit_stream )
-                            << ( -p_bit_stream->fifo.i_available );
-    p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
+
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    {
+        p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
+                                        << ( -p_bit_stream->fifo.i_available );
+        p_bit_stream->p_byte =
+                   (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+        p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
+        return;
+    }
+
+    UnalignedRemoveBits( p_bit_stream );
 }
 
 /*****************************************************************************
  * RemoveBits32 : removes 32 bits from the bit buffer (and as a side effect,
- *                refill it). This should be faster than RemoveBits, though
- *                RemoveBits will work, too.
+ *                refill it)
  *****************************************************************************/
-static __inline__ void RemoveBits32( bit_stream_t * p_bit_stream )
+#if (WORD_TYPE == uint32_t)
+static inline void RemoveBits32( bit_stream_t * p_bit_stream )
 {
-    p_bit_stream->fifo.buffer = GetWord( p_bit_stream )
-                        << (32 - p_bit_stream->fifo.i_available);
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    {
+        if( p_bit_stream->fifo.i_available )
+        {
+            p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte )
+                            << (32 - p_bit_stream->fifo.i_available);
+            p_bit_stream->p_byte =
+                       (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+            return;
+        }
+
+        p_bit_stream->p_byte =
+                   (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+        return;
+    }
+
+    p_bit_stream->fifo.i_available -= 32;
+    UnalignedRemoveBits( p_bit_stream );
 }
+#else
+#   define RemoveBits32( p_bit_stream )     RemoveBits( p_bit_stream, 32 )
+#endif
 
 /*****************************************************************************
  * GetBits : returns i_bits bits from the bit stream and removes them
+ *           XXX: do not use for 32 bits, see GetBits32
  *****************************************************************************/
-static __inline__ WORD_TYPE GetBits( bit_stream_t * p_bit_stream, int i_bits )
+static inline uint32_t GetBits( bit_stream_t * p_bit_stream,
+                                unsigned int i_bits )
 {
-    u32             i_result;
+    uint32_t        i_result;
 
     p_bit_stream->fifo.i_available -= i_bits;
+
     if( p_bit_stream->fifo.i_available >= 0 )
     {
-        i_result = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits);
+        i_result = p_bit_stream->fifo.buffer
+                        >> (8 * sizeof(WORD_TYPE) - i_bits);
         p_bit_stream->fifo.buffer <<= i_bits;
         return( i_result );
     }
 
-    i_result = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - i_bits);
-    p_bit_stream->fifo.buffer = GetWord( p_bit_stream );
-    i_result |= p_bit_stream->fifo.buffer
-                             >> (8 * sizeof(WORD_TYPE)
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    {
+        i_result = p_bit_stream->fifo.buffer
+                        >> (8 * sizeof(WORD_TYPE) - i_bits);
+        p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
+        p_bit_stream->p_byte =
+                   (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+        i_result |= p_bit_stream->fifo.buffer
+                        >> (8 * sizeof(WORD_TYPE)
                                      + p_bit_stream->fifo.i_available);
-    p_bit_stream->fifo.buffer <<= ( -p_bit_stream->fifo.i_available );
-    p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
+        p_bit_stream->fifo.buffer <<= ( -p_bit_stream->fifo.i_available );
+        p_bit_stream->fifo.i_available += sizeof(WORD_TYPE) * 8;
+        return( i_result );
+    }
 
-    return( i_result );
+    return UnalignedGetBits( p_bit_stream, i_bits );
+}
+
+/*****************************************************************************
+ * GetSignedBits : returns i_bits bits from the bit stream and removes them,
+ *                 using signed arithmetic
+ *                 XXX: do not use for 32 bits
+ *****************************************************************************/
+static inline int32_t GetSignedBits( bit_stream_t * p_bit_stream,
+                                     unsigned int i_bits )
+{
+    if( (unsigned int)p_bit_stream->fifo.i_available >= i_bits )
+    {
+        int32_t         i_result;
+
+        p_bit_stream->fifo.i_available -= i_bits;
+        i_result = (WORD_SIGNED)p_bit_stream->fifo.buffer
+                        >> (8 * sizeof(WORD_TYPE) - i_bits);
+        p_bit_stream->fifo.buffer <<= i_bits;
+        return( i_result );
+    }
+
+    /* You can probably do something a little faster, but now I'm tired. */
+    return( (WORD_SIGNED)(GetBits( p_bit_stream, i_bits ) << (32 - i_bits))
+             >> (32 - i_bits) );
 }
 
 /*****************************************************************************
  * GetBits32 : returns 32 bits from the bit stream and removes them
  *****************************************************************************/
-static __inline__ WORD_TYPE GetBits32( bit_stream_t * p_bit_stream )
+#if (WORD_TYPE == uint32_t)
+static inline uint32_t GetBits32( bit_stream_t * p_bit_stream )
 {
-    WORD_TYPE               i_result;
+    uint32_t        i_result;
 
-    i_result = p_bit_stream->fifo.buffer;
-    p_bit_stream->fifo.buffer = GetWord( p_bit_stream );
-    i_result |= p_bit_stream->fifo.buffer
+    if( p_bit_stream->fifo.i_available == 32 )
+    {
+        p_bit_stream->fifo.i_available = 0;
+        i_result = p_bit_stream->fifo.buffer;
+        p_bit_stream->fifo.buffer = 0;
+        return( i_result );
+    }
+
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    {
+        if( p_bit_stream->fifo.i_available )
+        {
+            i_result = p_bit_stream->fifo.buffer;
+            p_bit_stream->fifo.buffer = WORD_AT( p_bit_stream->p_byte );
+            p_bit_stream->p_byte =
+                       (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+            i_result |= p_bit_stream->fifo.buffer
                              >> (p_bit_stream->fifo.i_available);
-    p_bit_stream->fifo.buffer <<= (8 * sizeof(WORD_TYPE)
-                                    - p_bit_stream->fifo.i_available);
-    
-    return( i_result );
+            p_bit_stream->fifo.buffer <<= (32 - p_bit_stream->fifo.i_available);
+            return( i_result );
+        }
+
+        i_result = WORD_AT( p_bit_stream->p_byte );
+        p_bit_stream->p_byte =
+                   (byte_t *) ( ((WORD_TYPE *)p_bit_stream->p_byte) + 1 );
+        return( i_result );
+    }
+
+    p_bit_stream->fifo.i_available -= 32;
+    return UnalignedGetBits( p_bit_stream, 32 );
 }
+#else
+#   define GetBits32( p_bit_stream )    GetBits( p_bit_stream, 32 )
+#endif
 
 /*****************************************************************************
  * RealignBits : realigns the bit buffer on an 8-bit boundary
  *****************************************************************************/
-static __inline__ void RealignBits( bit_stream_t * p_bit_stream )
+static inline void RealignBits( bit_stream_t * p_bit_stream )
 {
     p_bit_stream->fifo.buffer <<= (p_bit_stream->fifo.i_available & 0x7);
     p_bit_stream->fifo.i_available &= ~0x7;
 }
 
 
-/*
- * Philosophy of the third implementation : the decoder asks for n bytes,
- * and we will copy them in its buffer.
- */
-
 /*****************************************************************************
  * GetChunk : reads a large chunk of data
  *****************************************************************************
  * The position in the stream must be byte-aligned, if unsure call
- * RealignBits(). p_buffer must to a buffer at least as big as i_buf_len
+ * RealignBits(). p_buffer must point to a buffer at least as big as i_buf_len
  * otherwise your code will crash.
  *****************************************************************************/
-static __inline__ void GetChunk( bit_stream_t * p_bit_stream,
-                                 byte_t * p_buffer, size_t i_buf_len )
+static inline void GetChunk( bit_stream_t * p_bit_stream,
+                             byte_t * p_buffer, size_t i_buf_len )
 {
     ptrdiff_t           i_available;
 
-    if( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
-            >= i_buf_len )
+    /* We need to take care because i_buf_len may be < 4. */
+    while( p_bit_stream->fifo.i_available > 0 && i_buf_len )
+    {
+        *p_buffer = p_bit_stream->fifo.buffer >> (8 * sizeof(WORD_TYPE) - 8);
+        p_buffer++;
+        i_buf_len--;
+        p_bit_stream->fifo.buffer <<= 8;
+        p_bit_stream->fifo.i_available -= 8;
+    }
+
+    i_available = p_bit_stream->p_end - p_bit_stream->p_byte;
+    if( i_available >= (ptrdiff_t)i_buf_len )
     {
-        memcpy( p_buffer, p_bit_stream->p_byte, i_buf_len );
+        p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
+                                           p_bit_stream->p_byte, i_buf_len );
         p_bit_stream->p_byte += i_buf_len;
     }
     else
     {
         do
         {
-            memcpy( p_buffer, p_bit_stream->p_byte, i_available );
+            p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
+                                           p_bit_stream->p_byte, i_available );
             p_bit_stream->p_byte = p_bit_stream->p_end;
             p_buffer += i_available;
             i_buf_len -= i_available;
-            p_bit_stream->pf_next_data_packet( p_bit_stream );
+            BitstreamNextDataPacket( p_bit_stream );
+            if( p_bit_stream->p_decoder_fifo->b_die )
+                return;
         }
         while( (i_available = p_bit_stream->p_end - p_bit_stream->p_byte)
-                <= i_buf_len );
+                <= (ptrdiff_t)i_buf_len );
 
         if( i_buf_len )
         {
-            memcpy( p_buffer, p_bit_stream->p_byte, i_buf_len );
+            p_bit_stream->p_decoder_fifo->p_vlc->pf_memcpy( p_buffer,
+                                           p_bit_stream->p_byte, i_buf_len );
             p_bit_stream->p_byte += i_buf_len;
         }
     }
+
+    if( p_bit_stream->p_byte <= p_bit_stream->p_end - sizeof(WORD_TYPE) )
+    {
+        AlignWord( p_bit_stream );
+    }
 }
 
 
@@ -435,94 +549,8 @@ static __inline__ void GetChunk( bit_stream_t * p_bit_stream,
  */
 
 /*****************************************************************************
- * decoder_config_t
- *****************************************************************************
- * Standard pointers given to the decoders as a toolbox.
+ * Prototypes from input_dec.c
  *****************************************************************************/
-typedef struct decoder_config_s
-{
-    u16                     i_id;
-    u8                      i_type;         /* type of the elementary stream */
-
-    struct stream_ctrl_s *  p_stream_ctrl;
-    struct decoder_fifo_s * p_decoder_fifo;
-    void                 (* pf_init_bit_stream)( struct bit_stream_s *,
-                                                 struct decoder_fifo_s * );
-} decoder_config_t;
+VLC_EXPORT( void, DecoderError, ( decoder_fifo_t * p_fifo ) );
 
-/*****************************************************************************
- * vdec_config_t
- *****************************************************************************
- * Pointers given to video decoders threads.
- *****************************************************************************/
-struct vout_thread_s;
-
-typedef struct vdec_config_s
-{
-    struct vout_thread_s *  p_vout;
-
-    struct picture_s *   (* pf_create_picture)( struct vout_thread_s *,
-                                                int i_type, int i_width,
-                                                int i_height );
-    void                 (* pf_destroy_picture)( struct vout_thread_s *,
-                                                 struct picture_s * );
-    void                 (* pf_display_picture)( struct vout_thread_s *,
-                                                 struct picture_s * );
-    void                 (* pf_date_picture)( struct vout_thread_s *,
-                                              struct picture_s *, mtime_t date );
-    void                 (* pf_link_picture)( struct vout_thread_s *,
-                                              struct picture_s *, mtime_t date );
-    void                 (* pf_unlink_picture)( struct vout_thread_s *,
-                                                struct picture_s *, mtime_t date );
-    struct subpicture_s *(* pf_create_subpicture)( struct vout_thread_s *,
-                                                   int i_type, int i_size );
-    void                 (* pf_destroy_subpicture)( struct vout_thread_s *,
-                                                    struct subpicture_s * );
-    void                 (* pf_display_subpicture)( struct vout_thread_s *,
-                                                    struct subpicture_s * );
-
-    decoder_config_t        decoder_config;
-} vdec_config_t;
-
-/*****************************************************************************
- * adec_config_t
- *****************************************************************************
- * Pointers given to audio decoders threads.
- *****************************************************************************/
-struct aout_thread_s;
-
-typedef struct adec_config_s
-{
-    struct aout_thread_s *  p_aout;
-
-    struct aout_fifo_s * (* pf_create_fifo)( struct aout_thread_s *,
-                                            struct aout_fifo_s * );
-    void                 (* pf_destroy_fifo)( struct aout_thread_s *);
-
-    decoder_config_t        decoder_config;
-} adec_config_t;
-
-
-/*
- * Communication interface between decoders and input
- */
-
-/*****************************************************************************
- * decoder_capabilities_t
- *****************************************************************************
- * Structure returned by a call to GetCapabilities() of the decoder.
- *****************************************************************************/
-typedef struct decoder_capabilities_s
-{
-    int                     i_dec_type;
-    u8                      i_stream_type;   /* == i_type in es_descriptor_t */
-    int                     i_weight; /* for a given stream type, the decoder
-                                       * with higher weight will be spawned  */
-
-    vlc_thread_t         (* pf_create_thread)( void * );
-} decoder_capabilities_t;
-
-/* Decoder types */
-#define NONE_D              0
-#define VIDEO_D             1
-#define AUDIO_D             2
+#endif /* "input_ext-dec.h" */