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-rw-r--r--gst-libs/ext/mplex/ac3strm_in.cc383
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diff --git a/gst-libs/ext/mplex/ac3strm_in.cc b/gst-libs/ext/mplex/ac3strm_in.cc
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+/*
+ * ac3strm_in.c: AC3 Audio strem class members handling scanning and
+ * buffering raw input stream.
+ *
+ * Copyright (C) 2001 Andrew Stevens <andrew.stevens@philips.com>
+ * Copyright (C) 2000,2001 Brent Byeler for original header-structure
+ * parsing code.
+ *
+ *
+ * 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 <math.h>
+#include <stdlib.h>
+
+#include "audiostrm.hh"
+#include "outputstream.hh"
+#include <cassert>
+
+
+
+#define AC3_SYNCWORD 0x0b77
+#define AC3_PACKET_SAMPLES 1536
+
+/// table for the available AC3 bitrates
+static const unsigned int ac3_bitrate_index[32] =
+{
+ 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192,
+ 224, 256, 320, 384, 448, 512, 576, 640,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static const unsigned int ac3_frame_size[3][32] =
+{
+ {64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384,
+ 448, 512, 640, 768, 896, 1024, 1152, 1280,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+ {69, 87, 104, 121, 139, 174, 208, 243, 278, 348, 417,
+ 487, 557, 696, 835, 975, 1114, 1253, 1393,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+ {96, 120, 144, 168, 192, 240, 288, 336, 384, 480, 576,
+ 672, 768, 960, 1152, 1344, 1536, 1728, 1920,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+};
+
+/// table for the available AC3 frequencies
+static const unsigned int ac3_frequency[4] = { 48000, 44100, 32000, 0 };
+
+
+AC3Stream::AC3Stream (IBitStream & ibs, OutputStream & into):
+AudioStream (ibs, into)
+{
+}
+
+bool
+AC3Stream::Probe (IBitStream & bs)
+{
+ return bs.getbits (16) == AC3_SYNCWORD;
+}
+
+
+/*************************************************************************
+ *
+ * Reads initial stream parameters and displays feedback banner to users
+ * @param stream_num AC3 substream ID
+ *************************************************************************/
+
+
+void
+AC3Stream::Init (const int stream_num)
+{
+ unsigned int framesize_code;
+
+ this->stream_num = stream_num;
+
+ MuxStream::Init (PRIVATE_STR_1, 1, // Buffer scale
+ default_buffer_size,
+ muxinto.vcd_zero_stuffing,
+ muxinto.buffers_in_audio, muxinto.always_buffers_in_audio);
+ mjpeg_info ("Scanning for header info: AC3 Audio stream %02x", stream_num);
+
+ InitAUbuffer ();
+ AU_start = bs.bitcount ();
+ if (bs.getbits (16) == AC3_SYNCWORD) {
+ num_syncword++;
+ bs.getbits (16); // CRC field
+ frequency = bs.getbits (2); // Sample rate code
+ framesize_code = bs.getbits (6); // Frame size code
+ framesize = ac3_frame_size[frequency][framesize_code >> 1];
+ framesize = (framesize_code & 1) && frequency == 1 ? (framesize + 1) << 1 : (framesize << 1);
+
+
+ size_frames[0] = framesize;
+ size_frames[1] = framesize;
+ num_frames[0]++;
+ access_unit.start = AU_start;
+ access_unit.length = framesize;
+ bit_rate = ac3_bitrate_index[framesize_code >> 1];
+ samples_per_second = ac3_frequency[frequency];
+
+
+ /* Presentation time-stamping */
+ access_unit.PTS = static_cast < clockticks > (decoding_order) *
+ static_cast < clockticks > (AC3_PACKET_SAMPLES) *
+ static_cast < clockticks > (CLOCKS) / samples_per_second;
+ access_unit.DTS = access_unit.PTS;
+ access_unit.dorder = decoding_order;
+ ++decoding_order;
+ aunits.append (access_unit);
+
+ } else {
+ mjpeg_error ("Invalid AC3 Audio stream header.");
+ exit (1);
+ }
+
+ OutputHdrInfo ();
+}
+
+/// @returns the current bitrate
+unsigned int
+AC3Stream::NominalBitRate ()
+{
+ return bit_rate;
+}
+
+/// Prefills the internal buffer for output multiplexing.
+/// @param frames_to_buffer the number of audio frames to read ahead
+void
+AC3Stream::FillAUbuffer (unsigned int frames_to_buffer)
+{
+ unsigned int framesize_code;
+
+ last_buffered_AU += frames_to_buffer;
+ mjpeg_debug ("Scanning %d MPEG audio frames to frame %d", frames_to_buffer, last_buffered_AU);
+
+ static int header_skip = 5; // Initially skipped past 5 bytes of header
+ int skip;
+ bool bad_last_frame = false;
+
+ while (!bs.eos () &&
+ decoding_order < last_buffered_AU) {
+ skip = access_unit.length - header_skip;
+ if (skip & 0x1)
+ bs.getbits (8);
+ if (skip & 0x2)
+ bs.getbits (16);
+ skip = skip >> 2;
+
+ for (int i = 0; i < skip; i++) {
+ bs.getbits (32);
+ }
+
+ prev_offset = AU_start;
+ AU_start = bs.bitcount ();
+ if (AU_start - prev_offset != access_unit.length * 8) {
+ bad_last_frame = true;
+ break;
+ }
+
+ /* Check we have reached the end of have another catenated
+ stream to process before finishing ... */
+ if ((syncword = bs.getbits (16)) != AC3_SYNCWORD) {
+ if (!bs.eos ()) {
+ mjpeg_error_exit1 ("Can't find next AC3 frame - broken bit-stream?");
+ }
+ break;
+ }
+
+ bs.getbits (16); // CRC field
+ bs.getbits (2); // Sample rate code TOOD: check for change!
+ framesize_code = bs.getbits (6);
+ framesize = ac3_frame_size[frequency][framesize_code >> 1];
+ framesize = (framesize_code & 1) && frequency == 1 ? (framesize + 1) << 1 : (framesize << 1);
+
+ access_unit.start = AU_start;
+ access_unit.length = framesize;
+ access_unit.PTS = static_cast < clockticks > (decoding_order) *
+ static_cast < clockticks > (AC3_PACKET_SAMPLES) *
+ static_cast < clockticks > (CLOCKS) / samples_per_second;;
+ access_unit.DTS = access_unit.PTS;
+ access_unit.dorder = decoding_order;
+ decoding_order++;
+ aunits.append (access_unit);
+ num_frames[0]++;
+
+ num_syncword++;
+
+
+#ifdef DEBUG_AC3_HEADERS
+ /* Some stuff to generate frame-header information */
+ printf ("bsid = %d\n", bs.getbits (5));
+ printf ("bsmode = 0x%1x\n", bs.getbits (3));
+ int acmode = bs.getbits (3);
+
+ printf ("acmode = 0x%1x\n", acmode);
+ if ((acmode & 0x1) && (acmode != 1))
+ printf ("cmixlev = %d\n", bs.getbits (2));
+ if ((acmode & 0x4))
+ printf ("smixlev = %d\n", bs.getbits (2));
+ if (acmode == 2)
+ printf ("dsurr = %d\n", bs.getbits (2));
+ printf ("lfeon = %d\n", bs.getbits (1));
+ printf ("dialnorm = %02d\n", bs.getbits (5));
+ int compre = bs.getbits (1);
+
+ printf ("compre = %d\n", compre);
+ if (compre)
+ printf ("compr = %02d\n", bs.getbits (8));
+ int langcode = bs.getbits (1);
+
+ printf ("langcode = %d\n", langcode);
+ if (langcode)
+ printf ("langcod = 0x%02x\n", bs.getbits (8));
+
+ while (bs.bitcount () % 8 != 0)
+ bs.getbits (1);
+ header_skip = (bs.bitcount () - AU_start) / 8;
+#endif
+ if (num_syncword >= old_frames + 10) {
+ mjpeg_debug ("Got %d frame headers.", num_syncword);
+ old_frames = num_syncword;
+ }
+
+
+ }
+ if (bad_last_frame) {
+ mjpeg_error_exit1 ("Last AC3 frame ended prematurely!\n");
+ }
+ last_buffered_AU = decoding_order;
+ eoscan = bs.eos ();
+
+}
+
+
+/// Closes the AC3 stream and prints some statistics.
+void
+AC3Stream::Close ()
+{
+ stream_length = AU_start >> 3;
+ mjpeg_info ("AUDIO_STATISTICS: %02x", stream_id);
+ mjpeg_info ("Audio stream length %lld bytes.", stream_length);
+ mjpeg_info ("Syncwords : %8u", num_syncword);
+ mjpeg_info ("Frames : %8u padded", num_frames[0]);
+ mjpeg_info ("Frames : %8u unpadded", num_frames[1]);
+
+ bs.close ();
+}
+
+/*************************************************************************
+ OutputAudioInfo
+ gibt gesammelte Informationen zu den Audio Access Units aus.
+
+ Prints information on audio access units
+*************************************************************************/
+
+void
+AC3Stream::OutputHdrInfo ()
+{
+ mjpeg_info ("AC3 AUDIO STREAM:");
+
+ mjpeg_info ("Bit rate : %8u bytes/sec (%3u kbit/sec)", bit_rate * 128, bit_rate);
+
+ if (frequency == 3)
+ mjpeg_info ("Frequency : reserved");
+ else
+ mjpeg_info ("Frequency : %d Hz", ac3_frequency[frequency]);
+
+}
+
+/**
+Reads the bytes neccessary to complete the current packet payload.
+@param to_read number of bytes to read
+@param dst byte buffer pointer to read to
+@returns the number of bytes read
+ */
+unsigned int
+AC3Stream::ReadPacketPayload (uint8_t * dst, unsigned int to_read)
+{
+ static unsigned int aus = 0;
+ static unsigned int rd = 0;
+
+ unsigned int bytes_read = bs.read_buffered_bytes (dst + 4, to_read - 4);
+
+ rd += bytes_read;
+ clockticks decode_time;
+
+ unsigned int first_header = (new_au_next_sec || au_unsent > bytes_read)
+ ? 0 : au_unsent;
+
+ // BUG BUG BUG: how do we set the 1st header pointer if we have
+ // the *middle* part of a large frame?
+ assert (first_header <= to_read - 2);
+
+
+ unsigned int syncwords = 0;
+ unsigned int bytes_muxed = bytes_read;
+
+ if (bytes_muxed == 0 || MuxCompleted ()) {
+ goto completion;
+ }
+
+
+ /* 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.
+
+ */
+
+ decode_time = RequiredDTS ();
+ while (au_unsent < bytes_muxed) {
+ // BUG BUG BUG: if we ever had odd payload / packet size we might
+ // split an AC3 frame in the middle of the syncword!
+ assert (bytes_muxed > 1);
+ bufmodel.Queued (au_unsent, decode_time);
+ bytes_muxed -= au_unsent;
+ if (new_au_next_sec)
+ ++syncwords;
+ aus += au->length;
+ if (!NextAU ()) {
+ goto completion;
+ }
+ 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) {
+ if (new_au_next_sec)
+ ++syncwords;
+ 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 (new_au_next_sec)
+ ++syncwords;
+ aus += au->length;
+ new_au_next_sec = NextAU ();
+ }
+completion:
+ // Generate the AC3 header...
+ // Note the index counts from the low byte of the offset so
+ // the smallest value is 1!
+
+ dst[0] = AC3_SUB_STR_0 + stream_num;
+ dst[1] = syncwords;
+ dst[2] = (first_header + 1) >> 8;
+ dst[3] = (first_header + 1) & 0xff;
+
+ return bytes_read + 4;
+}
+
+
+
+/*
+ * Local variables:
+ * c-file-style: "stroustrup"
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
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