mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-24 17:20:36 +00:00
384 lines
11 KiB
C++
384 lines
11 KiB
C++
|
/*
|
|||
|
|
* 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:
|
|||
|
|
*/
|