mpv/libmpdemux/mpeg_packetizer.c

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/*
* Copyright (C) 2006 Benjamin Zores
* Set of helper routines for building MPEG 1/2 PS/PES packets.
*
* Based on various code bororwed from vo_mpegpes/vo_dxr2 :
* (C) 2000 Ralph Metzler <ralph@convergence.de>
* Marcus Metzler <marcus@convergence.de>
* Gerard Lantau
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <unistd.h>
#include <string.h>
#include <inttypes.h>
#include "mp_msg.h"
#include "mpeg_packetizer.h"
#define PES_MAX_SIZE 2048
static unsigned char pes_header[PES_MAX_SIZE];
static unsigned char ps2_header[] = {
0x00, 0x00, 0x01, 0xba, 0x44, 0x00, 0x04, 0x00,
0x04, 0x01, 0x01, 0x86, 0xa3, 0xf8
};
static unsigned char ps1_header[] = {
0x00, 0x00, 0x01, 0xba, 0x21, 0x00,
0xb9, 0x37, 0x83, 0x80, 0xc3, 0x51,
};
/* Send MPEG <type> PES packet */
static int
send_mpeg_pes_packet_ll(unsigned char *data, int len, int id, uint64_t pts,
int type, unsigned char *header, int header_len,
int align4, int my_write (unsigned char *data, int len))
{
int ptslen = (pts ? 5 : 0);
int n = 0;
int idx, plen;
int hdr;
mp_msg (MSGT_HEADER, MSGL_DBG2,
"MPEG%d PES packet: 0x%x => %lu \n", type, id, pts);
memset (pes_header, '\0', PES_MAX_SIZE);
/* startcode */
pes_header[0] = 0;
pes_header[1] = 0;
pes_header[2] = 0x01;
pes_header[3] = id; /* stream id */
while (len > 0)
{
int payload_size = len; /* data + PTS */
if(type == 2)
hdr = 3;
else
hdr = (ptslen ? 0 : 1);
if (6 + hdr + ptslen + payload_size + header_len > PES_MAX_SIZE)
payload_size = PES_MAX_SIZE - 6 - hdr - ptslen - header_len;
if(align4)
payload_size &= ~3;
/* construct PES header: packetize */
plen = payload_size + hdr + ptslen + header_len;
pes_header[4] = plen >> 8;
pes_header[5] = plen & 255;
idx = 6;
if (ptslen)
{
int x;
if(type == 2)
{
pes_header[idx++] = 0x81;
pes_header[idx++] = 0x80;
pes_header[idx++] = ptslen;
}
/* presentation time stamp */
x = (0x02 << 4) | (((pts >> 30) & 0x07) << 1) | 1;
pes_header[idx++] = x;
x = ((((pts >> 15) & 0x7fff) << 1) | 1);
pes_header[idx++] = x >>8;
pes_header[idx++] = x & 255;
x = (((pts & 0x7fff) << 1) | 1);
pes_header[idx++] = x >> 8;
pes_header[idx++] = x & 255;
}
else
{
if(type == 2)
{
pes_header[idx++] = 0x81;
pes_header[idx++] = 0x00;
pes_header[idx++] = 0x00;
}
else
pes_header[idx++] = 0x0f;
}
if(header_len)
{
memcpy(&pes_header[idx], header, header_len);
idx += header_len;
}
my_write (pes_header, idx);
n = my_write (data, payload_size);
len -= n;
data += n;
ptslen = 0; /* store PTS only once, at first packet! */
if(align4 && len < 4)
break;
}
return n;
}
int
send_mpeg_pes_packet (unsigned char *data, int len, int id, uint64_t pts,
int type, int my_write (unsigned char *data, int len))
{
return send_mpeg_pes_packet_ll(data, len, id, pts, type, NULL, 0, 0, my_write);
}
/* Send MPEG <type> PS packet */
int
send_mpeg_ps_packet(unsigned char *data, int len, int id, uint64_t pts, int type,
int my_write (unsigned char *data, int len))
{
if(type == 2)
my_write (ps2_header, sizeof (ps2_header));
else
my_write (ps1_header, sizeof (ps1_header));
return send_mpeg_pes_packet (data, len, id, pts, type, my_write);
}
/* Send MPEG 2 LPCM packet */
int
send_mpeg_lpcm_packet(unsigned char* data, int len,
int id, uint64_t pts, int freq_id,
int my_write (unsigned char *data, int len))
{
unsigned char header[7] = {0xA0, 0x07, 0x00, 0x04, 0x0C, 1 | (freq_id << 4), 0x80};
return send_mpeg_pes_packet_ll(data, len, 0xBD, pts, 2, header, sizeof(header), 1, my_write);
}