- return block_Realloc( p_block, 0, p_block->i_buffer = len );
-}
-
-/*****************************************************************************
- * BlockTCP: Framed RTP/AVP packet reception for COMEDIA (see RFC4571)
- *****************************************************************************/
-static block_t *BlockTCP( access_t *p_access )
-{
- access_sys_t *p_sys = p_access->p_sys;
- block_t *p_block = p_sys->p_partial_frame;
-
- if( p_access->info.b_eof )
- return NULL;
-
- if( p_block == NULL )
- {
- /* MTU should always be 65535 in this case */
- p_sys->p_partial_frame = p_block = block_New( p_access, 2 + MTU );
- if (p_block == NULL)
- return NULL;
- }
-
- /* Read RTP framing */
- if (p_block->i_buffer < 2)
- {
- int i_read = net_Read( p_access, p_sys->fd, NULL,
- p_block->p_buffer + p_block->i_buffer,
- 2 - p_block->i_buffer, VLC_FALSE );
- if( i_read <= 0 )
- goto error;
-
- p_block->i_buffer += i_read;
- if (p_block->i_buffer < 2)
- return NULL;
- }
-
- uint16_t framelen = GetWLE( p_block->p_buffer );
- /* Read RTP frame */
- if( framelen > 0 )
- {
- int i_read = net_Read( p_access, p_sys->fd, NULL,
- p_block->p_buffer + p_block->i_buffer,
- 2 + framelen - p_block->i_buffer, VLC_FALSE );
- if( i_read <= 0 )
- goto error;
-
- p_block->i_buffer += i_read;
- }
-
- if( p_block->i_buffer < (2u + framelen) )
- return NULL; // incomplete frame
-
- /* Hide framing from RTP layer */
- p_block->p_buffer += 2;
- p_block->i_buffer -= 2;
- p_sys->p_partial_frame = NULL;
- return p_block;
-
-error:
- p_access->info.b_eof = VLC_TRUE;
- block_Release( p_block );
- p_sys->p_partial_frame = NULL;
- return NULL;
-}
-
-
-/*
- * rtp_ChainInsert - insert a p_block in the chain and
- * look at the sequence numbers.
- */
-static inline vlc_bool_t rtp_ChainInsert( access_t *p_access, block_t *p_block )
-{
- access_sys_t *p_sys = (access_sys_t *) p_access->p_sys;
- block_t *p_prev = NULL;
- block_t *p = p_sys->p_end;
- uint16_t i_new = (uint16_t) p_block->i_dts;
- uint16_t i_tmp = 0;
-
- if( !p_sys->p_list )
- {
- p_sys->p_list = p_block;
- p_sys->p_end = p_block;
- return VLC_TRUE;
- }
- /* walk through the queue from top down since the new packet is in
- most cases just appended to the end */
-
- for( ;; )
- {
- i_tmp = i_new - (uint16_t) p->i_dts;
-
- if( !i_tmp ) /* trash duplicate */
- break;
-
- if ( i_tmp < 32768 )
- { /* insert after this block ( i_new > p->i_dts ) */
- p_block->p_next = p->p_next;
- p->p_next = p_block;
- p_block->p_prev = p;
- if (p_prev)
- {
- p_prev->p_prev = p_block;
- msg_Dbg(p_access, "RTP reordering: insert after %d, new %d",
- (uint16_t) p->i_dts, i_new );
- }
- else
- {
- p_sys->p_end = p_block;
- }
- return VLC_TRUE;
- }
- if( p == p_sys->p_list )
- { /* we've reached bottom of chain */
- i_tmp = p_sys->i_last_seqno - i_new;
- if( !p_access->info.b_prebuffered || (i_tmp > 32767) )
- {
- msg_Dbg(p_access, "RTP reordering: prepend %d before %d",
- i_new, (uint16_t) p->i_dts );
- p_block->p_next = p;
- p->p_prev = p_block;
- p_sys->p_list = p_block;
- return VLC_TRUE;
- }
-
- if( !i_tmp ) /* trash duplicate */
- break;
-
- /* reordering failed - append the packet to the end of queue */
- msg_Dbg(p_access, "RTP: sequence changed (or buffer too small) "
- "new: %d, buffer %d...%d", i_new, (uint16_t) p->i_dts,
- (uint16_t) p_sys->p_end->i_dts);
- p_sys->p_end->p_next = p_block;
- p_block->p_prev = p_sys->p_end;
- p_sys->p_end = p_block;
- return VLC_TRUE;
- }
- p_prev = p;
- p = p->p_prev;
- }
- block_Release( p_block );
- return VLC_FALSE;
-}
-
-/*****************************************************************************
- * BlockParseRTP: decapsulate the RTP packet and return it
- *****************************************************************************/
-static block_t *BlockParseRTP( access_t *p_access, block_t *p_block )
-{
- int i_payload_type;
- size_t i_skip = RTP_HEADER_LEN;
-
- if( p_block == NULL )
- return NULL;
-
- if( p_block->i_buffer < RTP_HEADER_LEN )
- {
- msg_Dbg( p_access, "short RTP packet received" );
- goto trash;
- }
-
- /* Parse the header and make some verifications.
- * See RFC 3550. */
- // Version number:
- if( ( p_block->p_buffer[0] >> 6 ) != 2)
- {
- msg_Dbg( p_access, "RTP version is %u instead of 2",
- p_block->p_buffer[0] >> 6 );
- goto trash;
- }
- // Padding bit:
- uint8_t pad = (p_block->p_buffer[0] & 0x20)
- ? p_block->p_buffer[p_block->i_buffer - 1] : 0;
- // CSRC count:
- i_skip += (p_block->p_buffer[0] & 0x0F) * 4;
- // Extension header:
- if (p_block->p_buffer[0] & 0x10) /* Extension header */
- {
- i_skip += 4;
- if ((size_t)p_block->i_buffer < i_skip)
- goto trash;
-
- i_skip += 4 * GetWBE( p_block->p_buffer + i_skip - 2 );
- }
-
- i_payload_type = p_block->p_buffer[1] & 0x7F;
-
- /* Remember sequence number in i_dts */
- p_block->i_pts = mdate();
- p_block->i_dts = (mtime_t) GetWBE( p_block->p_buffer + 2 );
-
- /* FIXME: use rtpmap */
- const char *psz_demux = NULL;
-
- switch( i_payload_type )
- {
- case 14: // MPA: MPEG Audio (RFC2250, §3.4)
- i_skip += 4; // 32 bits RTP/MPA header
- psz_demux = "mpga";
- break;
-
- case 32: // MPV: MPEG Video (RFC2250, §3.5)
- i_skip += 4; // 32 bits RTP/MPV header
- if( (size_t)p_block->i_buffer < i_skip )
- goto trash;
- if( p_block->p_buffer[i_skip - 3] & 0x4 )
- {
- /* MPEG2 Video extension header */
- /* TODO: shouldn't we skip this too ? */
- }
- psz_demux = "mpgv";
- break;
-
- case 33: // MP2: MPEG TS (RFC2250, §2)
- /* plain TS over RTP */
- psz_demux = "ts";
- break;
-
- case 72: /* muxed SR */
- case 73: /* muxed RR */
- case 74: /* muxed SDES */
- case 75: /* muxed BYE */
- case 76: /* muxed APP */
- goto trash; /* ooh! ignoring RTCP is evil! */
-
- default:
- msg_Dbg( p_access, "unsupported RTP payload type: %u", i_payload_type );
- goto trash;
- }
-
- if( (size_t)p_block->i_buffer < (i_skip + pad) )
- goto trash;
-
- /* Remove the RTP header */
- p_block->i_buffer -= i_skip;
- p_block->p_buffer += i_skip;
-
- /* This is the place for deciphering and authentication */
-
- /* Remove padding (at the end) */
- p_block->i_buffer -= pad;
-
-#if 0
- /* Emulate packet loss */
- if ( (i_sequence_number % 4000) == 0)
- {
- msg_Warn( p_access, "Emulating packet drop" );
- block_Release( p_block );
- return NULL;
- }
-#endif
-
- if( !p_access->psz_demux || !*p_access->psz_demux )
- {
- free( p_access->psz_demux );
- p_access->psz_demux = strdup( psz_demux );
- }
-
- return p_block;
-
-trash:
- block_Release( p_block );
- return NULL;
-}
-
-/*****************************************************************************
- * BlockRTP: receives an RTP packet, parses it, queues it queue,
- * then dequeues the oldest packet and returns it to input/demux.
- ****************************************************************************/
-static block_t *BlockRTP( access_t *p_access )
-{
- access_sys_t *p_sys = p_access->p_sys;
- block_t *p;
-
- while ( !p_sys->p_list ||
- ( mdate() - p_sys->p_list->i_pts ) < p_sys->i_rtp_late )
- {
- p = BlockParseRTP( p_access,
- p_sys->b_framed_rtp ? BlockTCP( p_access )
- : BlockUDP( p_access ) );
- if ( !p )
- return NULL;
-
- rtp_ChainInsert( p_access, p );
- }
-
- p = p_sys->p_list;
- p_sys->p_list = p_sys->p_list->p_next;
- p_sys->i_last_seqno++;
- if( p_sys->i_last_seqno != (uint16_t) p->i_dts )
- {
- msg_Dbg( p_access, "RTP: packet(s) lost, expected %d, got %d",
- p_sys->i_last_seqno, (uint16_t) p->i_dts );
- p_sys->i_last_seqno = (uint16_t) p->i_dts;
- }
- p->p_next = NULL;
- return p;
-}
-
-/*****************************************************************************
- * BlockPrebufferRTP: waits until we have at least two RTP datagrams,
- * so that we can synchronize the RTP sequence number.
- * This is only useful for non-reliable transport protocols.
- ****************************************************************************/
-static block_t *BlockPrebufferRTP( access_t *p_access, block_t *p_block )
-{
- access_sys_t *p_sys = p_access->p_sys;
- mtime_t i_first = mdate();
- int i_count = 0;
- block_t *p = p_block;
-
- if( BlockParseRTP( p_access, p_block ) == NULL )
- return NULL;
-
- for( ;; )
- {
- mtime_t i_date = mdate();
-
- if( p && rtp_ChainInsert( p_access, p ))
- i_count++;
-
- /* Require at least 2 packets in the buffer */
- if( i_count > 2 && (i_date - i_first) > p_sys->i_rtp_late )
- break;
-
- p = BlockParseRTP( p_access, BlockUDP( p_access ) );
- if( !p && (i_date - i_first) > p_sys->i_rtp_late )
- {
- msg_Err( p_access, "error in RTP prebuffering!" );
- return NULL;
- }
- }
-
- msg_Dbg( p_access, "RTP: prebuffered %d packets", i_count - 1 );
- p_access->info.b_prebuffered = VLC_TRUE;
- p = p_sys->p_list;
- p_sys->p_list = p_sys->p_list->p_next;
- p_sys->i_last_seqno = (uint16_t) p->i_dts;
- p->p_next = NULL;
- return p;
-}
-
-static block_t *BlockStartRTP( access_t *p_access )
-{
- p_access->pf_block = BlockRTP;
- return BlockPrebufferRTP( p_access, BlockUDP( p_access ) );
-}
-
-
-/*****************************************************************************
- * BlockChoose: decide between RTP and UDP
- *****************************************************************************/
-static block_t *BlockChoose( access_t *p_access )
-{
- block_t *p_block;
- int i_rtp_version;
- int i_payload_type;
-
- if( ( p_block = BlockUDP( p_access ) ) == NULL )
- return NULL;
-
- if( p_block->p_buffer[0] == 0x47 )
- {
- msg_Dbg( p_access, "detected TS over raw UDP" );
- p_access->pf_block = BlockUDP;
- p_access->info.b_prebuffered = VLC_TRUE;
- return p_block;
- }
-
- if( p_block->i_buffer < RTP_HEADER_LEN )
- return p_block;
-
- /* Parse the header and make some verifications.
- * See RFC 3550. */
-
- i_rtp_version = p_block->p_buffer[0] >> 6;
- i_payload_type = ( p_block->p_buffer[1] & 0x7F );
-
- if( i_rtp_version != 2 )
- {
- msg_Dbg( p_access, "no supported RTP header detected" );
- p_access->pf_block = BlockUDP;
- p_access->info.b_prebuffered = VLC_TRUE;
- return p_block;
- }
-
- switch( i_payload_type )
- {
- case 33:
- msg_Dbg( p_access, "detected MPEG2 TS over RTP" );
- p_access->psz_demux = strdup( "ts" );
- break;
-
- case 14:
- msg_Dbg( p_access, "detected MPEG Audio over RTP" );
- p_access->psz_demux = strdup( "mpga" );
- break;
-
- case 32:
- msg_Dbg( p_access, "detected MPEG Video over RTP" );
- p_access->psz_demux = strdup( "mpgv" );
- break;
-
- default:
- msg_Dbg( p_access, "no RTP header detected" );
- p_access->pf_block = BlockUDP;
- p_access->info.b_prebuffered = VLC_TRUE;
- return p_block;
- }
-
- p_access->pf_block = BlockRTP;
- return BlockPrebufferRTP( p_access, p_block );