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-rw-r--r--gst-libs/ext/mplex/lpcmstrm_in.cc304
1 files changed, 304 insertions, 0 deletions
diff --git a/gst-libs/ext/mplex/lpcmstrm_in.cc b/gst-libs/ext/mplex/lpcmstrm_in.cc
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+++ b/gst-libs/ext/mplex/lpcmstrm_in.cc
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+/*
+ * lpcmstrm_in.c: LPCM 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 <string.h>
+
+#include "audiostrm.hh"
+#include "outputstream.hh"
+#include <cassert>
+
+
+
+
+LPCMStream::LPCMStream (IBitStream & ibs, OutputStream & into):
+AudioStream (ibs, into)
+{
+}
+
+bool LPCMStream::Probe (IBitStream & bs)
+{
+ return true;
+}
+
+
+/*************************************************************************
+ *
+ * Reads initial stream parameters and displays feedback banner to users
+ *
+ *************************************************************************/
+
+
+void
+LPCMStream::Init (const int 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: LPCM Audio stream %02x", stream_num);
+
+ InitAUbuffer ();
+
+ AU_start = bs.bitcount ();
+
+ // This is a dummy debug version that simply assumes 48kHz
+ // two channel 16 bit sample LPCM
+ samples_per_second = 48000;
+ channels = 2;
+ bits_per_sample = 16;
+ bytes_per_frame =
+ samples_per_second * channels * bits_per_sample / 8 * ticks_per_frame_90kHz / 90000;
+ frame_index = 0;
+ dynamic_range_code = 0x80;
+
+ /* Presentation/decoding time-stamping */
+ access_unit.start = AU_start;
+ access_unit.length = bytes_per_frame;
+ access_unit.PTS = static_cast < clockticks > (decoding_order) *
+ (CLOCKS_per_90Kth_sec * ticks_per_frame_90kHz);
+ access_unit.DTS = access_unit.PTS;
+ access_unit.dorder = decoding_order;
+ decoding_order++;
+ aunits.append (access_unit);
+
+ OutputHdrInfo ();
+}
+
+unsigned int
+LPCMStream::NominalBitRate ()
+{
+ return samples_per_second * channels * bits_per_sample;
+}
+
+
+
+void
+LPCMStream::FillAUbuffer (unsigned int frames_to_buffer)
+{
+ last_buffered_AU += frames_to_buffer;
+ mjpeg_debug ("Scanning %d MPEG LPCM audio frames to frame %d",
+ frames_to_buffer, last_buffered_AU);
+
+ static int header_skip = 0; // 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;
+ mjpeg_debug ("Buffering frame %d (%d bytes)\n", decoding_order - 1, 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;
+ }
+ // Here we would check for header data but LPCM has no headers...
+ if (bs.eos ())
+ break;
+
+ access_unit.start = AU_start;
+ access_unit.length = bytes_per_frame;
+ access_unit.PTS = static_cast < clockticks > (decoding_order) *
+ (CLOCKS_per_90Kth_sec * ticks_per_frame_90kHz);
+ access_unit.DTS = access_unit.PTS;
+ access_unit.dorder = decoding_order;
+ decoding_order++;
+ aunits.append (access_unit);
+ num_frames[0]++;
+
+ num_syncword++;
+
+ if (num_syncword >= old_frames + 10) {
+ mjpeg_debug ("Got %d frame headers.", num_syncword);
+ old_frames = num_syncword;
+ }
+ mjpeg_debug ("Got frame %d\n", decoding_order);
+
+ }
+ if (bad_last_frame) {
+ mjpeg_error_exit1 ("Last LPCM frame ended prematurely!\n");
+ }
+ last_buffered_AU = decoding_order;
+ eoscan = bs.eos ();
+
+}
+
+
+
+void
+LPCMStream::Close ()
+{
+ stream_length = AU_start / 8;
+ mjpeg_info ("AUDIO_STATISTICS: %02x", stream_id);
+ mjpeg_info ("Audio stream length %lld bytes.", stream_length);
+ mjpeg_info ("Frames : %8u ", num_frames[0]);
+ bs.close ();
+}
+
+/*************************************************************************
+ OutputAudioInfo
+ gibt gesammelte Informationen zu den Audio Access Units aus.
+
+ Prints information on audio access units
+*************************************************************************/
+
+void
+LPCMStream::OutputHdrInfo ()
+{
+ mjpeg_info ("LPCM AUDIO STREAM:");
+
+ mjpeg_info ("Bit rate : %8u bytes/sec (%3u kbit/sec)",
+ NominalBitRate () / 8, NominalBitRate ());
+ mjpeg_info ("Channels : %d\n", channels);
+ mjpeg_info ("Bits per sample: %d\n", bits_per_sample);
+ mjpeg_info ("Frequency : %d Hz", samples_per_second);
+
+}
+
+
+unsigned int
+LPCMStream::ReadPacketPayload (uint8_t * dst, unsigned int to_read)
+{
+ unsigned int header_size = LPCMStream::StreamHeaderSize ();
+ unsigned int bytes_read = bs.read_buffered_bytes (dst + header_size,
+ to_read - header_size);
+ clockticks decode_time;
+ bool starting_frame_found = false;
+ uint8_t starting_frame_index = 0;
+
+ int starting_frame_offset = (new_au_next_sec || au_unsent > bytes_read)
+ ? 0 : au_unsent;
+
+ unsigned int frames = 0;
+ unsigned int bytes_muxed = bytes_read;
+
+ if (bytes_muxed == 0 || MuxCompleted ()) {
+ goto completion;
+ }
+
+
+ /* Work through what's left of the current frames and the
+ following frames's updating the info until we reach a point where
+ an frame had to be split between packets.
+
+ 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) {
+ assert (bytes_muxed > 1);
+ bufmodel.Queued (au_unsent, decode_time);
+ bytes_muxed -= au_unsent;
+ if (new_au_next_sec) {
+ ++frames;
+ if (!starting_frame_found) {
+ starting_frame_index = static_cast < uint8_t > (au->dorder % 20);
+ starting_frame_found = true;
+ }
+ }
+ 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 the tail end of
+ // // an already started frame or a new one. We need this info 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)
+ ++frames;
+ 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)
+ ++frames;
+ new_au_next_sec = NextAU ();
+ }
+completion:
+ // Generate the LPCM header...
+ // Note the index counts from the low byte of the offset so
+ // the smallest value is 1!
+ dst[0] = LPCM_SUB_STR_0 + stream_num;
+ dst[1] = frames;
+ dst[2] = (starting_frame_offset + 1) >> 8;
+ dst[3] = (starting_frame_offset + 1) & 0xff;
+ unsigned int bps_code;
+
+ switch (bits_per_sample) {
+ case 16:
+ bps_code = 0;
+ break;
+ case 20:
+ bps_code = 1;
+ break;
+ case 24:
+ bps_code = 2;
+ break;
+ default:
+ bps_code = 3;
+ break;
+ }
+ dst[4] = starting_frame_index;
+ unsigned int bsf_code = (samples_per_second == 48000) ? 0 : 1;
+ unsigned int channels_code = channels - 1;
+
+ dst[5] = (bps_code << 6) | (bsf_code << 4) | channels_code;
+ dst[6] = dynamic_range_code;
+ return bytes_read + header_size;
+}
+
+
+
+/*
+ * Local variables:
+ * c-file-style: "stroustrup"
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
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