mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-09-09 05:38:58 +00:00
329 lines
9.3 KiB
C++
329 lines
9.3 KiB
C++
/*
|
||
* audiostrm_in.c: MPEG Audio strem class members handling scanning
|
||
* and buffering raw input 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 <math.h>
|
||
#include <stdlib.h>
|
||
|
||
#include "audiostrm.hh"
|
||
#include "outputstream.hh"
|
||
|
||
|
||
static const char *mpa_audio_version[4] = {
|
||
"2.5",
|
||
"2.0",
|
||
"reserved",
|
||
"1.0"
|
||
};
|
||
|
||
static const unsigned int mpa_bitrates_kbps[4][3][16] = {
|
||
{ /* MPEG audio V2.5 */
|
||
{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0},
|
||
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
|
||
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0}
|
||
},
|
||
{ /*RESERVED*/ {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
|
||
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
|
||
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
|
||
},
|
||
{ /* MPEG audio V2 */
|
||
{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0},
|
||
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
|
||
{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0}
|
||
},
|
||
{ /* MPEG audio V1 */
|
||
{0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0},
|
||
{0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0},
|
||
{0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0}
|
||
}
|
||
|
||
};
|
||
|
||
|
||
static const int mpa_freq_table[4][4] = {
|
||
/* MPEG audio V2.5 */
|
||
{11025, 12000, 8000, 0},
|
||
/* RESERVED */
|
||
{0, 0, 0, 0},
|
||
/* MPEG audio V2 */
|
||
{22050, 24000, 16000, 0},
|
||
/* MPEG audio V1 */
|
||
{44100, 48000, 32000, 0}
|
||
};
|
||
|
||
static const char mpa_stereo_mode[4][15] =
|
||
{ "stereo", "joint stereo", "dual channel", "single channel" };
|
||
static const char mpa_copyright_status[2][20] = { "no copyright", "copyright protected" };
|
||
static const char mpa_original_bit[2][10] = { "copy", "original" };
|
||
static const char mpa_emphasis_mode[4][20] =
|
||
{ "none", "50/15 microseconds", "reserved", "CCITT J.17" };
|
||
static const unsigned int mpa_slots[4] = { 12, 144, 144, 0 };
|
||
static const unsigned int mpa_samples[4] = { 384, 1152, 1152, 0 };
|
||
|
||
|
||
|
||
MPAStream::MPAStream (IBitStream & ibs, OutputStream & into):
|
||
AudioStream (ibs, into)
|
||
{
|
||
}
|
||
|
||
bool
|
||
MPAStream::Probe (IBitStream & bs)
|
||
{
|
||
return bs.getbits (11) == AUDIO_SYNCWORD;
|
||
}
|
||
|
||
|
||
/*************************************************************************
|
||
*
|
||
* Reads initial stream parameters and displays feedback banner to users
|
||
*
|
||
*************************************************************************/
|
||
|
||
|
||
void
|
||
MPAStream::Init (const int stream_num)
|
||
{
|
||
int padding_bit;
|
||
|
||
MuxStream::Init (AUDIO_STR_0 + stream_num, 0, // Buffer scale
|
||
muxinto.audio_buffer_size,
|
||
muxinto.vcd_zero_stuffing,
|
||
muxinto.buffers_in_audio, muxinto.always_buffers_in_audio);
|
||
mjpeg_info ("Scanning for header info: Audio stream %02x", AUDIO_STR_0 + stream_num);
|
||
|
||
InitAUbuffer ();
|
||
|
||
/* A.Stevens 2000 - update to be compatible up to MPEG2.5
|
||
*/
|
||
AU_start = bs.bitcount ();
|
||
if (bs.getbits (11) == AUDIO_SYNCWORD) {
|
||
num_syncword++;
|
||
version_id = bs.getbits (2);
|
||
layer = 3 - bs.getbits (2); /* 0..2 not 1..3!! */
|
||
protection = bs.get1bit ();
|
||
bit_rate_code = bs.getbits (4);
|
||
frequency = bs.getbits (2);
|
||
padding_bit = bs.get1bit ();
|
||
bs.get1bit ();
|
||
mode = bs.getbits (2);
|
||
mode_extension = bs.getbits (2);
|
||
copyright = bs.get1bit ();
|
||
original_copy = bs.get1bit ();
|
||
emphasis = bs.getbits (2);
|
||
|
||
framesize =
|
||
mpa_bitrates_kbps[version_id][layer][bit_rate_code] *
|
||
mpa_slots[layer] * 1000 / mpa_freq_table[version_id][frequency];
|
||
|
||
size_frames[0] = framesize;
|
||
size_frames[1] = framesize + (layer == 0 ? 4 : 1);
|
||
num_frames[padding_bit]++;
|
||
access_unit.start = AU_start;
|
||
access_unit.length = size_frames[padding_bit];
|
||
|
||
samples_per_second = mpa_freq_table[version_id][frequency];
|
||
|
||
/* Presentation time-stamping */
|
||
access_unit.PTS = static_cast < clockticks > (decoding_order) *
|
||
static_cast < clockticks > (mpa_samples[layer]) *
|
||
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 MPEG Audio stream header.");
|
||
exit (1);
|
||
}
|
||
|
||
|
||
OutputHdrInfo ();
|
||
}
|
||
|
||
unsigned int
|
||
MPAStream::NominalBitRate ()
|
||
{
|
||
return mpa_bitrates_kbps[version_id][layer][bit_rate_code] * 128;
|
||
}
|
||
|
||
|
||
unsigned int
|
||
MPAStream::SizeFrame (int rate_code, int padding)
|
||
{
|
||
return mpa_bitrates_kbps[version_id][layer][rate_code] *
|
||
mpa_slots[layer] * 1000 / mpa_freq_table[version_id][frequency] + padding;
|
||
}
|
||
|
||
void
|
||
MPAStream::FillAUbuffer (unsigned int frames_to_buffer)
|
||
{
|
||
unsigned int i;
|
||
unsigned int padding_bit;
|
||
|
||
last_buffered_AU += frames_to_buffer;
|
||
|
||
mjpeg_debug ("Scanning %d MPEG audio frames to frame %d", frames_to_buffer, last_buffered_AU);
|
||
|
||
while (!bs.eos () &&
|
||
decoding_order < last_buffered_AU) {
|
||
|
||
skip = access_unit.length - 4;
|
||
if (skip & 0x1)
|
||
bs.getbits (8);
|
||
if (skip & 0x2)
|
||
bs.getbits (16);
|
||
skip = skip >> 2;
|
||
|
||
for (i = 0; i < skip; i++) {
|
||
bs.getbits (32);
|
||
}
|
||
prev_offset = AU_start;
|
||
AU_start = bs.bitcount ();
|
||
|
||
/* Check we have reached the end of have another catenated
|
||
stream to process before finishing ... */
|
||
if ((syncword = bs.getbits (11)) != AUDIO_SYNCWORD) {
|
||
if (!bs.eobs) {
|
||
/* There appears to be another catenated stream... */
|
||
int next;
|
||
|
||
mjpeg_warn ("End of component bit-stream ... seeking next");
|
||
/* Catenated stream must start on byte boundary */
|
||
syncword = (syncword << (8 - AU_start % 8));
|
||
next = bs.getbits (8 - (AU_start % 8));
|
||
AU_start = bs.bitcount () - 11;
|
||
syncword = syncword | next;
|
||
if (syncword != AUDIO_SYNCWORD) {
|
||
mjpeg_warn ("Failed to find start of next stream at %d prev %d !", (int) AU_start / 8,
|
||
(int)prev_offset / 8);
|
||
break;
|
||
}
|
||
} else
|
||
/* No catenated stream... finished! */
|
||
break;
|
||
}
|
||
// Skip version_id:2, layer:2, protection:1
|
||
(void) bs.getbits (5);
|
||
int rate_code = bs.getbits (4);
|
||
|
||
// Skip frequency
|
||
(void) bs.getbits (2);
|
||
|
||
padding_bit = bs.get1bit ();
|
||
access_unit.start = AU_start;
|
||
access_unit.length = SizeFrame (rate_code, padding_bit);
|
||
access_unit.PTS =
|
||
static_cast < clockticks > (decoding_order) * static_cast < clockticks >
|
||
(mpa_samples[layer]) * 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[padding_bit]++;
|
||
|
||
bs.getbits (9);
|
||
|
||
num_syncword++;
|
||
|
||
if (num_syncword >= old_frames + 10) {
|
||
mjpeg_debug ("Got %d frame headers.", num_syncword);
|
||
old_frames = num_syncword;
|
||
|
||
}
|
||
|
||
|
||
|
||
}
|
||
last_buffered_AU = decoding_order;
|
||
eoscan = bs.eos ();
|
||
|
||
}
|
||
|
||
|
||
|
||
void
|
||
MPAStream::Close ()
|
||
{
|
||
stream_length = AU_start >> 3;
|
||
mjpeg_info ("AUDIO_STATISTICS: %02x", stream_id);
|
||
mjpeg_info ("Audio stream length %d bytes.", (int)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
|
||
MPAStream::OutputHdrInfo ()
|
||
{
|
||
unsigned int bitrate;
|
||
|
||
bitrate = mpa_bitrates_kbps[version_id][layer][bit_rate_code];
|
||
|
||
|
||
mjpeg_info ("AUDIO STREAM:");
|
||
mjpeg_info ("Audio version : %s", mpa_audio_version[version_id]);
|
||
mjpeg_info ("Layer : %8u", layer + 1);
|
||
|
||
if (protection == 0)
|
||
mjpeg_info ("CRC checksums : yes");
|
||
else
|
||
mjpeg_info ("CRC checksums : no");
|
||
|
||
if (bit_rate_code == 0)
|
||
mjpeg_info ("Bit rate : free");
|
||
else if (bit_rate_code == 0xf)
|
||
mjpeg_info ("Bit rate : reserved");
|
||
else
|
||
mjpeg_info ("Bit rate : %8u bytes/sec (%3u kbit/sec)", bitrate * 128, bitrate);
|
||
|
||
if (frequency == 3)
|
||
mjpeg_info ("Frequency : reserved");
|
||
else
|
||
mjpeg_info ("Frequency : %d Hz", mpa_freq_table[version_id][frequency]);
|
||
|
||
mjpeg_info ("Mode : %8u %s", mode, mpa_stereo_mode[mode]);
|
||
mjpeg_info ("Mode extension : %8u", mode_extension);
|
||
mjpeg_info ("Copyright bit : %8u %s", copyright, mpa_copyright_status[copyright]);
|
||
mjpeg_info ("Original/Copy : %8u %s", original_copy, mpa_original_bit[original_copy]);
|
||
mjpeg_info ("Emphasis : %8u %s", emphasis, mpa_emphasis_mode[emphasis]);
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
* Local variables:
|
||
* c-file-style: "stroustrup"
|
||
* tab-width: 4
|
||
* indent-tabs-mode: nil
|
||
* End:
|
||
*/
|