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Diffstat (limited to 'ext/mplex/inputstrm.cc')
| -rw-r--r-- | ext/mplex/inputstrm.cc | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/ext/mplex/inputstrm.cc b/ext/mplex/inputstrm.cc new file mode 100644 index 000000000..4a19724a5 --- /dev/null +++ b/ext/mplex/inputstrm.cc @@ -0,0 +1,249 @@ + +/* + * inputstrm.c: Base classes related to muxing out input streams into + * the output stream. + * + * Copyright (C) 2001 Andrew Stevens <andrew.stevens@philips.com> + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + + +#include <config.h> +#include <assert.h> +#include "fastintfns.h" +#include "inputstrm.hh" +#include "outputstream.hh" + +MuxStream::MuxStream ():init (false) +{ +} + + +void +MuxStream::Init (const int strm_id, + const unsigned int _buf_scale, + const unsigned int buf_size, + const unsigned int _zero_stuffing, bool bufs_in_first, bool always_bufs) +{ + stream_id = strm_id; + nsec = 0; + zero_stuffing = _zero_stuffing; + buffer_scale = _buf_scale; + buffer_size = buf_size; + bufmodel.Init (buf_size); + buffers_in_header = bufs_in_first; + always_buffers_in_header = always_bufs; + new_au_next_sec = true; + init = true; +} + + + +unsigned int +MuxStream::BufferSizeCode () +{ + if (buffer_scale == 1) + return buffer_size / 1024; + else if (buffer_scale == 0) + return buffer_size / 128; + else + assert (false); +} + + + +ElementaryStream::ElementaryStream (IBitStream & ibs, OutputStream & into, stream_kind _kind): +InputStream (ibs), muxinto (into), kind (_kind), buffer_min (INT_MAX), buffer_max (1) +{ +} + + +bool ElementaryStream::NextAU () +{ + Aunit * + p_au = + next (); + + if (p_au != NULL) { + au = p_au; + au_unsent = p_au->length; + return true; + } else { + au_unsent = 0; + return false; + } +} + + +Aunit * +ElementaryStream::Lookahead () +{ + return aunits.lookahead (); +} + +unsigned int +ElementaryStream::BytesToMuxAUEnd (unsigned int sector_transport_size) +{ + return (au_unsent / min_packet_data) * sector_transport_size + + (au_unsent % min_packet_data) + (sector_transport_size - min_packet_data); +} + + +/****************************************************************** + * ElementaryStream::ReadPacketPayload + * + * Reads the stream data from actual input stream, updates decode + * buffer model and current access unit information from the + * look-ahead scanning buffer to account for bytes_muxed bytes being + * muxed out. Particular important is the maintenance of "au_unsent" + * the count of how much data in the current AU remains umuxed. It + * not only allows us to keep track of AU's but is also used for + * generating substream headers + * + * Unless we need to over-ride it to handle sub-stream headers + * The packet payload for an elementary stream is simply the parsed and + * spliced buffered stream data.. + * + ******************************************************************/ + + + +unsigned int +ElementaryStream::ReadPacketPayload (uint8_t * dst, unsigned int to_read) +{ + unsigned int actually_read = bs.read_buffered_bytes (dst, to_read); + + Muxed (actually_read); + return actually_read; +} + + + + +void +ElementaryStream::Muxed (unsigned int bytes_muxed) +{ + clockticks decode_time; + + if (bytes_muxed == 0 || MuxCompleted ()) + return; + + + /* Work through what's left of the current AU and the following AU's + updating the info until we reach a point where an AU had to be + split between packets. + NOTE: It *is* possible for this loop to iterate. + + The DTS/PTS field for the packet in this case would have been + given the that for the first AU to start in the packet. + Whether Joe-Blow's hardware VCD player handles this properly is + another matter of course! + */ + + decode_time = RequiredDTS (); + while (au_unsent < bytes_muxed) { + + bufmodel.Queued (au_unsent, decode_time); + bytes_muxed -= au_unsent; + if (!NextAU ()) + return; + new_au_next_sec = true; + decode_time = RequiredDTS (); + }; + + // We've now reached a point where the current AU overran or + // fitted exactly. We need to distinguish the latter case + // so we can record whether the next packet starts with an + // existing AU or not - info we need to decide what PTS/DTS + // info to write at the start of the next packet. + + if (au_unsent > bytes_muxed) { + + bufmodel.Queued (bytes_muxed, decode_time); + au_unsent -= bytes_muxed; + new_au_next_sec = false; + } else // if (au_unsent == bytes_muxed) + { + bufmodel.Queued (bytes_muxed, decode_time); + if (!NextAU ()) + return; + new_au_next_sec = true; + } + +} + +bool +ElementaryStream::MuxPossible (clockticks currentSCR) +{ + return (!RunOutComplete () && bufmodel.Space () > max_packet_data); +} + + +void +ElementaryStream::UpdateBufferMinMax () +{ + buffer_min = buffer_min < (int) bufmodel.Space ()? buffer_min : bufmodel.Space (); + buffer_max = buffer_max > (int) bufmodel.Space ()? buffer_max : bufmodel.Space (); +} + + + +void +ElementaryStream::AllDemuxed () +{ + bufmodel.Flushed (); +} + +void +ElementaryStream::DemuxedTo (clockticks SCR) +{ + bufmodel.Cleaned (SCR); +} + +bool +ElementaryStream::MuxCompleted () +{ + return au_unsent == 0; +} + +void +ElementaryStream::SetSyncOffset (clockticks sync_offset) +{ + timestamp_delay = sync_offset; +} + +Aunit * +ElementaryStream::next () +{ + Aunit *res; + + while (AUBufferNeedsRefill ()) { + FillAUbuffer (FRAME_CHUNK); + } + res = aunits.next (); + return res; +} + + + + +/* + * Local variables: + * c-file-style: "stroustrup" + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ |