git.sesse.net Git - vlc/blob - include/input.h

   1 /******************************************************************************
   2  * input.h: input thread interface
   3  * (c)1999 VideoLAN
   4  ******************************************************************************/
   5
   6 /******************************************************************************
   7  * Constants related to input
   8  ******************************************************************************/
   9 #define TS_PACKET_SIZE      188                        /* size of a TS packet */
  10 #define PES_HEADER_SIZE     14      /* size of the first part of a PES header */
  11 #define PSI_SECTION_SIZE    4096             /* Maximum size of a PSI section */
  12
  13 /******************************************************************************
  14  * ts_packet_t
  15  ******************************************************************************
  16  * Describe a TS packet.
  17  ******************************************************************************/
  18 typedef struct ts_packet_s
  19 {
  20     /* Nothing before this line, the code relies on that */
  21     byte_t                  buffer[TS_PACKET_SIZE];     /* raw TS data packet */
  22
  23     /* Decoders information */
  24     unsigned int            i_payload_start;
  25                                    /* start of the PES payload in this packet */
  26     unsigned int            i_payload_end;                     /* guess ? :-) */
  27
  28     /* Used to chain the TS packets that carry data for a same PES or PSI */
  29     struct ts_packet_s      *  p_prev_ts;
  30     struct ts_packet_s      *  p_next_ts;
  31 } ts_packet_t;
  32
  33 /******************************************************************************
  34  * pes_packet_t
  35  ******************************************************************************
  36  * Describes an PES packet, with its properties, and pointers to the TS packets
  37  * containing it.
  38  ******************************************************************************/
  39 typedef struct pes_packet_s
  40 {
  41     /* PES properties */
  42     boolean_t               b_data_loss;   /* The previous (at least) PES packet
  43             * has been lost. The decoders will have to find a way to recover. */
  44     boolean_t               b_data_alignment; /* used to find the beginning of a
  45                                                * video or audio unit          */
  46     boolean_t               b_has_pts;        /* is the following field set ? */
  47     mtime_t                 i_pts;  /* the PTS for this packet (if set above) */
  48     boolean_t               b_random_access;
  49              /* if TRUE, in the payload of this packet, there is the first byte
  50               * of a video sequence header, or the first byte of an audio frame.
  51               */
  52     u8                      i_stream_id;               /* payload type and id */
  53     int                     i_pes_size;     /* size of the current PES packet */
  54     int                     i_ts_packets; /* number of TS packets in this PES */
  55
  56     /* Demultiplexer environment */
  57     boolean_t               b_discard_payload;   /* is the packet messed up ? */
  58     byte_t *                p_pes_header;        /* pointer to the PES header */
  59     byte_t *                p_pes_header_save;            /* temporary buffer */
  60
  61     /* Pointers to TS packets (TS packets are then linked by the p_prev_ts and
  62        p_next_ts fields of the ts_packet_t struct) */
  63     ts_packet_t *           p_first_ts;   /* The first TS packet containing this
  64                                            * PES (used by decoders). */
  65     ts_packet_t *           p_last_ts; /* The last TS packet gathered at present
  66                                         * (used by the demultiplexer). */
  67 } pes_packet_t;
  68
  69 /******************************************************************************
  70  * psi_section_t
  71  ******************************************************************************
  72  * Describes a PSI section. Beware, it doesn't contain pointers to the TS
  73  * packets that contain it as for a PES, but the data themselves
  74  ******************************************************************************/
  75 typedef struct psi_section_s
  76 {
  77     byte_t        buffer[PSI_SECTION_SIZE];
  78
  79     boolean_t     b_running_section;    /* Is there a section being decoded ? */
  80
  81     u16 i_length;
  82     u16 i_current_position;
  83 } psi_section_t;
  84
  85
  86 /******************************************************************************
  87  * es_descriptor_t: elementary stream descriptor
  88  ******************************************************************************
  89  * Describes an elementary stream, and includes fields required to handle and
  90  * demultiplex this elementary stream.
  91  ******************************************************************************/
  92 typedef struct es_descriptor_t
  93 {
  94     u16                     i_id;            /* stream ID, PID for TS streams */
  95     u8                      i_type;                            /* stream type */
  96
  97     boolean_t               b_pcr;         /* does the stream include a PCR ? */
  98     /* ?? b_pcr will be replaced by something else: since a PCR can't be shared
  99      * between several ES, we will probably store the PCR fields directly here,
 100      * and one of those fields will probably (again) be used as a test of the
 101      * PCR presence */
 102     boolean_t               b_psi;  /* does the stream have to be handled by the
 103                                                                 PSI decoder ? */
 104     /* Markers */
 105     int                     i_continuity_counter;
 106     boolean_t               b_discontinuity;
 107     boolean_t               b_random;
 108
 109     /* PES packets */
 110     pes_packet_t *          p_pes_packet;
 111                                        /* current PES packet we are gathering */
 112
 113     /* PSI packets */
 114     psi_section_t *         p_psi_section;           /* idem for a PSI stream */
 115
 116     /* Decoder informations */
 117     void *                  p_dec;     /* p_dec is void *, since we don't know a
 118                                         * priori whether it is adec_thread_t or
 119                                         * vdec_thread_t. We will use explicit
 120                                         * casts. */
 121
 122     /* ?? video stream descriptor ? */
 123     /* ?? audio stream descriptor ? */
 124     /* ?? hierarchy descriptor ? */
 125     /* ?? target background grid descriptor ? */
 126     /* ?? video window descriptor ? */
 127     /* ?? ISO 639 language descriptor ? */
 128
 129 #ifdef STATS
 130     /* Stats */
 131     count_t                 c_bytes;                      /* total bytes read */
 132     count_t                 c_payload_bytes;/* total of payload usefull bytes */
 133     count_t                 c_packets;                  /* total packets read */
 134     count_t                 c_invalid_packets;        /* invalid packets read */
 135     /* ?? ... other stats */
 136 #endif
 137 } es_descriptor_t;
 138
 139 /* Special PID values - note that the PID is only on 13 bits, and that values
 140  * greater than 0x1fff have no meaning in a stream */
 141 #define PROGRAM_ASSOCIATION_TABLE_PID   0x0000
 142 #define CONDITIONNAL_ACCESS_TABLE_PID   0x0001                    /* not used */
 143 #define EMPTY_PID                       0xffff     /* empty record in a table */
 144
 145 /* ES streams types - see ISO/IEC 13818-1 table 2-29 numbers */
 146 #define MPEG1_VIDEO_ES          0x01
 147 #define MPEG2_VIDEO_ES          0x02
 148 #define MPEG1_AUDIO_ES          0x03
 149 #define MPEG2_AUDIO_ES          0x04
 150 #define AC3_AUDIO_ES            0x81
 151
 152 /******************************************************************************
 153  * program_descriptor_t
 154  ******************************************************************************
 155  * Describes a program and list associated elementary streams. It is build by
 156  * the PSI decoder upon the informations carried in program map sections
 157  ******************************************************************************/
 158 typedef struct
 159 {
 160     /* Program characteristics */
 161     u16                     i_number;                       /* program number */
 162     u8                      i_version;                      /* version number */
 163     boolean_t               b_is_ok;        /* Is the description up to date ?*/
 164     u16                     i_pcr_pid;                              /* PCR ES */
 165
 166     int i_es_number;
 167     es_descriptor_t **      ap_es;                 /* array of pointers to ES */
 168
 169 #ifdef DVB_EXTENSIONS
 170     /* Service Descriptor (program name) */
 171     u8                      i_srv_type;
 172     char*                   psz_srv_name;
 173 #endif
 174
 175     /* ?? target background grid descriptor ? */
 176     /* ?? video window descriptor ? */
 177     /* ?? ISO 639 language descriptor ? */
 178
 179 #ifdef STATS
 180     /* Stats */
 181     /* ?? ...stats */
 182 #endif
 183 } pgrm_descriptor_t;
 184
 185 /******************************************************************************
 186  * pcr_descriptor_t
 187  ******************************************************************************
 188  * Contains informations used to synchronise the decoder with the server
 189  ******************************************************************************/
 190
 191 typedef struct pcr_descriptor_struct
 192 {
 193     /* system_date = PTS_date + delta_pcr + delta_absolute */
 194     mtime_t                 delta_pcr;
 195     mtime_t                 delta_absolute;
 196
 197     mtime_t                 last_pcr;
 198
 199     u32                     i_synchro_state;
 200     count_t                 c_average_count;
 201                             /* counter used to compute dynamic average values */
 202 } pcr_descriptor_t;
 203
 204 /******************************************************************************
 205  * stream_descriptor_t
 206  ******************************************************************************
 207  * Describes a transport stream and list its associated programs. Build upon
 208  * the informations carried in program association sections
 209  ******************************************************************************/
 210 typedef struct
 211 {
 212     u16                     i_stream_id;                         /* stream id */
 213
 214     /* Program Association Table status */
 215     u8                      i_PAT_version;                  /* version number */
 216     boolean_t               b_is_PAT_complete;        /* Is the PAT complete ?*/
 217     u8                      i_known_PAT_sections;
 218                                       /* Number of section we received so far */
 219     byte_t                  a_known_PAT_sections[32];
 220                                                  /* Already received sections */
 221
 222     /* Program Map Table status */
 223     boolean_t               b_is_PMT_complete;        /* Is the PMT complete ?*/
 224     u8                      i_known_PMT_sections;
 225                                       /* Number of section we received so far */
 226     byte_t                  a_known_PMT_sections[32];
 227                                                  /* Already received sections */
 228
 229     /* Service Description Table status */
 230     u8                      i_SDT_version;                  /* version number */
 231     boolean_t               b_is_SDT_complete;        /* Is the SDT complete ?*/
 232     u8                      i_known_SDT_sections;
 233                                       /* Number of section we received so far */
 234     byte_t                  a_known_SDT_sections[32];
 235                                                  /* Already received sections */
 236
 237     /* Programs description */
 238     int i_pgrm_number;                    /* Number of program number we have */
 239     pgrm_descriptor_t **    ap_programs;         /* Array of pointers to pgrm */
 240
 241 #ifdef STATS
 242     /* Stats */
 243     /* ?? ...stats */
 244 #endif
 245 } stream_descriptor_t;
 246
 247 /******************************************************************************
 248  * input_netlist_t
 249  ******************************************************************************/
 250 typedef struct
 251 {
 252     vlc_mutex_t             lock;                /* netlist modification lock */
 253     struct iovec            p_ts_free[INPUT_MAX_TS + INPUT_TS_READ_ONCE];
 254                                            /* FIFO or LIFO of free TS packets */
 255     ts_packet_t *           p_ts_packets;
 256                                /* pointer to the first TS packet we allocated */
 257
 258     pes_packet_t *          p_pes_free[INPUT_MAX_PES + 1];
 259                                           /* FIFO or LIFO of free PES packets */
 260     pes_packet_t *          p_pes_packets;
 261                               /* pointer to the first PES packet we allocated */
 262
 263     /* To use the efficiency of the scatter/gather IO operations. We implemented
 264      * it in 2 ways, as we don't know yet which one is better : as a FIFO (code
 265      * simplier) or as a LIFO stack (when we doesn't care of the ordering, this
 266      * allow to drastically improve the cache performance) */
 267 #ifdef INPUT_LIFO_TS_NETLIST
 268     int                     i_ts_index;
 269 #else
 270     int                     i_ts_start, i_ts_end;
 271 #endif
 272 #ifdef INPUT_LIFO_PES_NETLIST
 273     int                     i_pes_index;
 274 #else
 275     int                     i_pes_start, i_pes_end;
 276 #endif
 277 } input_netlist_t;
 278
 279
 280
 281 /******************************************************************************
 282  * input_thread_t
 283  ******************************************************************************
 284  * This structure includes all the local static variables of an input thread,
 285  * including the netlist and the ES descriptors
 286  * Note that p_es must be defined as a static table, otherwise we would have to
 287  * update all reference to it each time the table would be reallocated
 288  ******************************************************************************/
 289
 290 /* Function pointers used in structure */
 291 typedef int  (input_open_t)     ( p_input_thread_t p_input );
 292 typedef int  (input_read_t)     ( p_input_thread_t p_input, const struct iovec *p_vector,
 293                                    size_t i_count );
 294 typedef void (input_close_t)    ( p_input_thread_t p_input );
 295
 296 /* Structure */
 297 typedef struct input_thread_s
 298 {
 299     /* Thread properties and locks */
 300     boolean_t                   b_die;                          /* 'die' flag */
 301     boolean_t                   b_error;                          /* deadlock */
 302     vlc_thread_t                thread_id;         /* id for thread functions */
 303     vlc_mutex_t                 programs_lock;  /* programs modification lock */
 304     vlc_mutex_t                 es_lock;              /* es modification lock */
 305     int *                       pi_status;           /* temporary status flag */
 306
 307     /* Input method description */
 308     int                         i_method;                     /* input method */
 309     int                         i_handle;           /* file/socket descriptor */
 310     char *                      psz_source;                         /* source */
 311     int                         i_port;                     /* port number */
 312     int                         i_vlan;                 /* id for vlan method */
 313     input_open_t *              p_Open;               /* opener of the method */
 314     input_read_t *              p_Read;                   /* reading function */
 315     input_close_t *             p_Close;               /* destroying function */
 316
 317     /* General stream description */
 318     stream_descriptor_t *   p_stream;                           /* PAT tables */
 319     es_descriptor_t         p_es[INPUT_MAX_ES]; /* carried elementary streams */
 320     pcr_descriptor_t *      p_pcr;     /* PCR struct used for synchronisation */
 321
 322     /* List of streams to demux */
 323     es_descriptor_t *       pp_selected_es[INPUT_MAX_SELECTED_ES];
 324
 325     /* Netlists */
 326     input_netlist_t         netlist;                             /* see above */
 327
 328     /* Default settings for spawned decoders */
 329     p_aout_thread_t             p_aout;      /* audio output thread structure */
 330     p_vout_thread_t             p_vout;                /* video output thread */
 331
 332 #ifdef STATS
 333     /* Statistics */
 334     count_t                     c_loops;                   /* number of loops */
 335     count_t                     c_bytes;                        /* bytes read */
 336     count_t                     c_payload_bytes;      /* payload useful bytes */
 337     count_t                     c_packets_read;               /* packets read */
 338     count_t                     c_packets_trashed;         /* trashed packets */
 339 #endif
 340 } input_thread_t;
 341
 342 /* Input methods */
 343 #define INPUT_METHOD_NONE           0             /* input thread is inactive */
 344 #define INPUT_METHOD_TS_FILE       10        /* TS stream is read from a file */
 345 #define INPUT_METHOD_TS_UCAST      20                       /* TS UDP unicast */
 346 #define INPUT_METHOD_TS_MCAST      21                     /* TS UDP multicast */
 347 #define INPUT_METHOD_TS_BCAST      22                     /* TS UDP broadcast */
 348 #define INPUT_METHOD_TS_VLAN_BCAST 32          /* TS UDP broadcast with VLANs */
 349
 350 /*****************************************************************************
 351  * Prototypes
 352  *****************************************************************************/
 353 input_thread_t *input_CreateThread      ( int i_method, char *psz_source, int i_port,
 354                                           int i_vlan, p_vout_thread_t p_vout,
 355                                           p_aout_thread_t p_aout, int *pi_status );
 356 void            input_DestroyThread     ( input_thread_t *p_input, int *pi_status );
 357
 358
 359 int             input_OpenAudioStream   ( input_thread_t *p_input, int i_pid );
 360 void            input_CloseAudioStream  ( input_thread_t *p_input, int i_pid );
 361 int             input_OpenVideoStream   ( input_thread_t *p_input, int i_pid );
 362 void            input_CloseVideoStream  ( input_thread_t *p_input, int i_pid );