* mpeg_system.c: TS, PS and PES management
*****************************************************************************
* Copyright (C) 1998-2001 VideoLAN
- * $Id: mpeg_system.c,v 1.81 2002/03/01 00:33:18 massiot Exp $
+ * $Id: mpeg_system.c,v 1.82 2002/03/04 23:56:37 massiot Exp $
*
* Authors: Christophe Massiot <massiot@via.ecp.fr>
* Michel Lespinasse <walken@via.ecp.fr>
vlc_mutex_unlock( &p_input->stream.stream_lock );
}
+/*****************************************************************************
+ * input_ReadPS: store a PS packet into a data_buffer_t
+ *****************************************************************************/
+#define PEEK( SIZE ) \
+ i_error = input_Peek( p_input, &p_peek, SIZE ); \
+ if( i_error == -1 ) \
+ { \
+ return( -1 ); \
+ } \
+ else if( i_error < SIZE ) \
+ { \
+ /* EOF */ \
+ return( 0 ); \
+ }
+
+ssize_t input_ReadPS( input_thread_t * p_input, data_packet_t ** pp_data )
+{
+ byte_t * p_peek;
+ size_t i_packet_size;
+ ssize_t i_error, i_read;
+
+ /* Read what we believe to be a packet header. */
+ PEEK( 4 );
+
+ if( *p_peek || *(p_peek + 1) || *(p_peek + 2) != 1 )
+ {
+ if( *p_peek || *(p_peek + 1) || *(p_peek + 2) )
+ {
+ /* It is common for MPEG-1 streams to pad with zeros
+ * (although it is forbidden by the recommendation), so
+ * don't bother everybody in this case. */
+ intf_WarnMsg( 3, "input warning: garbage at input (0x%x%x%x%x)",
+ *p_peek, *(p_peek + 1), *(p_peek + 2), *(p_peek + 3) );
+ }
+
+ /* This is not the startcode of a packet. Read the stream
+ * until we find one. */
+ while( *p_peek || *(p_peek + 1) || *(p_peek + 2) != 1 )
+ {
+ p_input->p_current_data++;
+ PEEK( 4 );
+ }
+ /* Packet found. */
+ }
+
+ /* 0x1B9 == SYSTEM_END_CODE, it is only 4 bytes long. */
+ if( p_peek[3] != 0xB9 )
+ {
+ /* The packet is at least 6 bytes long. */
+ PEEK( 6 );
+
+ if( p_peek[3] != 0xBA )
+ {
+ /* That's the case for all packets, except pack header. */
+ i_packet_size = (p_peek[4] << 8) | p_peek[5];
+ }
+ else
+ {
+ /* Pack header. */
+ if( (p_peek[4] & 0xC0) == 0x40 )
+ {
+ /* MPEG-2 */
+ i_packet_size = 8;
+ }
+ else if( (p_peek[4] & 0xF0) == 0x20 )
+ {
+ /* MPEG-1 */
+ i_packet_size = 6;
+ }
+ else
+ {
+ intf_ErrMsg( "Unable to determine stream type" );
+ return( -1 );
+ }
+ }
+ }
+ else
+ {
+ /* System End Code */
+ i_packet_size = -2;
+ }
+
+ /* Fetch a packet of the appropriate size. */
+ i_read = input_SplitBuffer( p_input, pp_data, i_packet_size + 6 );
+ if( i_read <= 0 )
+ {
+ return( i_read );
+ }
+
+ /* In MPEG-2 pack headers we still have to read stuffing bytes. */
+ if( ((*pp_data)->p_demux_start[3] == 0xBA) && (i_packet_size == 8) )
+ {
+ size_t i_stuffing = ((*pp_data)->p_demux_start[13] & 0x7);
+ /* Force refill of the input buffer - though we don't care
+ * about p_peek. Please note that this is unoptimized. */
+ PEEK( i_stuffing );
+ p_input->p_current_data += i_stuffing;
+ }
+
+ return( 1 );
+}
+
+#undef PEEK
+
/*****************************************************************************
* input_ParsePS: read the PS header
*****************************************************************************/
* TS Demultiplexing
*/
+/*****************************************************************************
+ * input_ReadTS: store a TS packet into a data_buffer_t
+ *****************************************************************************/
+#define PEEK( SIZE ) \
+ i_error = input_Peek( p_input, &p_peek, SIZE ); \
+ if( i_error == -1 ) \
+ { \
+ return( -1 ); \
+ } \
+ else if( i_error < SIZE ) \
+ { \
+ /* EOF */ \
+ return( 0 ); \
+ }
+
+ssize_t input_ReadTS( input_thread_t * p_input, data_packet_t ** pp_data )
+{
+ byte_t * p_peek;
+ ssize_t i_error, i_read;
+
+ PEEK( 1 );
+
+ if( *p_peek != TS_SYNC_CODE )
+ {
+ intf_WarnMsg( 3, "input warning: garbage at input (%x)", *p_peek );
+
+ if( p_input->i_mtu )
+ {
+ while( *p_peek != TS_SYNC_CODE )
+ {
+ /* Try to resync on next packet. */
+ PEEK( TS_PACKET_SIZE );
+ p_input->p_current_data += TS_PACKET_SIZE;
+ PEEK( 1 );
+ }
+ }
+ else
+ {
+ /* Move forward until we find 0x47 (and hope it's the good
+ * one... FIXME) */
+ while( *p_peek != TS_SYNC_CODE )
+ {
+ p_input->p_current_data++;
+ PEEK( 1 );
+ }
+ }
+ }
+
+ i_read = input_SplitBuffer( p_input, pp_data, TS_PACKET_SIZE );
+ if( i_read <= 0 )
+ {
+ return( i_read );
+ }
+
+ return( 1 );
+}
+
/*****************************************************************************
* input_DemuxTS: first step of demultiplexing: the TS header
*****************************************************************************/
projects / vlc / blobdiff