real.c

mplayer播放器的源码

/*
 * This file was ported to MPlayer from xine CVS real.c,v 1.8 2003/03/30 17:11:50
 */

/*
 * Copyright (C) 2002 the xine project
 *
 * This file is part of xine, a free video player.
 *
 * xine 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.
 *
 * xine 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
 *
 *
 * special functions for real streams.
 * adopted from joschkas real tools.
 *
 */

#include <stdio.h>
#include <string.h>

#include "../config.h"
#include "libavutil/common.h"
#include "real.h"
#include "asmrp.h"
#include "sdpplin.h"
#include "xbuffer.h"
#if USE_LIBAVUTIL_SO
#include "ffmpeg/md5.h"
#else
#include "libavutil/md5.h"
#endif
#include "libavutil/intreadwrite.h"
#include "../http.h"
#include "mp_msg.h"

/*
#define LOG
*/

#define XOR_TABLE_SIZE 37

static const unsigned char xor_table[XOR_TABLE_SIZE] = {
    0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
    0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
    0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
    0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
    0x10, 0x57, 0x05, 0x18, 0x54 };


#define BUF_SIZE 4096

#ifdef LOG
static void hexdump (const char *buf, int length) {

  int i;

  printf (" hexdump> ");
  for (i = 0; i < length; i++) {
    unsigned char c = buf[i];

    printf ("%02x", c);

    if ((i % 16) == 15)
      printf ("\n         ");

    if ((i % 2) == 1)
      printf (" ");

  }
  printf ("\n");
}
#endif


static void real_calc_response_and_checksum (char *response, char *chksum, char *challenge) {

  int   ch_len;
  int   i;
  unsigned char zres[16], buf[128];

  /* initialize return values */
  memset(response, 0, 64);
  memset(chksum, 0, 34);

  /* initialize buffer */
  memset(buf, 0, 128);
  AV_WB32(buf, 0xa1e9149d);
  AV_WB32(buf+4, 0x0e6b3b59);

  /* some (length) checks */
  if (challenge != NULL)
  {
    ch_len = strlen (challenge);

    if (ch_len == 40) /* what a hack... */
    {
      challenge[32]=0;
      ch_len=32;
    }
    if ( ch_len > 56 ) ch_len=56;
    
    /* copy challenge to buf */
    memcpy(buf+8, challenge, ch_len);
  }
  
    /* xor challenge bytewise with xor_table */
    for (i=0; i<XOR_TABLE_SIZE; i++)
      buf[8+i] ^= xor_table[i];

  av_md5_sum(zres, buf, 64);
 
  /* convert zres to ascii string */
  for (i=0; i<16; i++ )
    sprintf(response+i*2, "%02x", zres[i]);

  /* add tail */
  strcpy (&response[32], "01d0a8e3");

  /* calculate checksum */
  for (i=0; i<8; i++)
    chksum[i] = response[i*4];
}


/*
 * takes a MLTI-Chunk and a rule number got from match_asm_rule,
 * returns a pointer to selected data and number of bytes in that.
 */

static int select_mlti_data(const char *mlti_chunk, int mlti_size, int selection, char **out) {

  int numrules, codec, size;
  int i;
  
  /* MLTI chunk should begin with MLTI */

  if ((mlti_chunk[0] != 'M')
      ||(mlti_chunk[1] != 'L')
      ||(mlti_chunk[2] != 'T')
      ||(mlti_chunk[3] != 'I'))
  {
#ifdef LOG
    printf("libreal: MLTI tag not detected, copying data\n");
#endif
    *out = xbuffer_copyin(*out, 0, mlti_chunk, mlti_size);
    return mlti_size;
  }

  mlti_chunk+=4;

  /* next 16 bits are the number of rules */
  numrules=AV_RB16(mlti_chunk);
  if (selection >= numrules) return 0;

  /* now <numrules> indices of codecs follows */
  /* we skip to selection                     */
  mlti_chunk+=(selection+1)*2;

  /* get our index */
  codec=AV_RB16(mlti_chunk);

  /* skip to number of codecs */
  mlti_chunk+=(numrules-selection)*2;

  /* get number of codecs */
  numrules=AV_RB16(mlti_chunk);

  if (codec >= numrules) {
    mp_msg(MSGT_STREAM, MSGL_WARN, "realrtsp: codec index >= number of codecs. %i %i\n",
      codec, numrules);
    return 0;
  }

  mlti_chunk+=2;
 
  /* now seek to selected codec */
  for (i=0; i<codec; i++) {
    size=AV_RB32(mlti_chunk);
    mlti_chunk+=size+4;
  }
  
  size=AV_RB32(mlti_chunk);

#ifdef LOG
  hexdump(mlti_chunk+4, size);
#endif
  *out = xbuffer_copyin(*out, 0, mlti_chunk+4, size);
  return size;
}

/*
 * looking at stream description.
 */

static rmff_header_t *real_parse_sdp(char *data, char **stream_rules, uint32_t bandwidth) {

  sdpplin_t *desc;
  rmff_header_t *header;
  char *buf;
  int len, i;
  int max_bit_rate=0;
  int avg_bit_rate=0;
  int max_packet_size=0;
  int avg_packet_size=0;
  int duration=0;
  

  if (!data) return NULL;

  desc=sdpplin_parse(data);

  if (!desc) return NULL;
  
  buf = xbuffer_init(2048);
  header=calloc(1,sizeof(rmff_header_t));

  header->fileheader=rmff_new_fileheader(4+desc->stream_count);
  header->cont=rmff_new_cont(
      desc->title,
      desc->author,
      desc->copyright,
      desc->abstract);
  header->data=rmff_new_dataheader(0,0);
  header->streams=calloc(1,sizeof(rmff_mdpr_t*)*(desc->stream_count+1));
#ifdef LOG
    printf("number of streams: %u\n", desc->stream_count);
#endif

  for (i=0; i<desc->stream_count; i++) {

    int j=0;
    int n;
    char b[64];
    int rulematches[MAX_RULEMATCHES];

#ifdef LOG
    printf("calling asmrp_match with:\n%s\n%u\n", desc->stream[i]->asm_rule_book, bandwidth);
#endif
    n=asmrp_match(desc->stream[i]->asm_rule_book, bandwidth, rulematches);
    for (j=0; j<n; j++) {
#ifdef LOG
      printf("asmrp rule match: %u for stream %u\n", rulematches[j], desc->stream[i]->stream_id);
#endif
      sprintf(b,"stream=%u;rule=%u,", desc->stream[i]->stream_id, rulematches[j]);
      *stream_rules = xbuffer_strcat(*stream_rules, b);
    }

    if (!desc->stream[i]->mlti_data) {
	len = 0;
	buf = NULL;
    } else
    len=select_mlti_data(desc->stream[i]->mlti_data, desc->stream[i]->mlti_data_size, rulematches[0], &buf);
    
    header->streams[i]=rmff_new_mdpr(
	desc->stream[i]->stream_id,
        desc->stream[i]->max_bit_rate,
        desc->stream[i]->avg_bit_rate,
        desc->stream[i]->max_packet_size,
        desc->stream[i]->avg_packet_size,
        desc->stream[i]->start_time,
        desc->stream[i]->preroll,
        desc->stream[i]->duration,
        desc->stream[i]->stream_name,
        desc->stream[i]->mime_type,
	len,
	buf);

    duration=FFMAX(duration,desc->stream[i]->duration);
    max_bit_rate+=desc->stream[i]->max_bit_rate;
    avg_bit_rate+=desc->stream[i]->avg_bit_rate;
    max_packet_size=FFMAX(max_packet_size, desc->stream[i]->max_packet_size);
    if (avg_packet_size)
      avg_packet_size=(avg_packet_size + desc->stream[i]->avg_packet_size) / 2;
    else
      avg_packet_size=desc->stream[i]->avg_packet_size;
  }
  
  if (*stream_rules && strlen(*stream_rules) && (*stream_rules)[strlen(*stream_rules)-1] == ',')
    (*stream_rules)[strlen(*stream_rules)-1]=0; /* delete last ',' in stream_rules */

  header->prop=rmff_new_prop(
      max_bit_rate,
      avg_bit_rate,
      max_packet_size,
      avg_packet_size,
      0,
      duration,
      0,
      0,
      0,
      desc->stream_count,
      desc->flags);

  rmff_fix_header(header);
  buf = xbuffer_free(buf);
  sdpplin_free(desc);

  return header;
}

int real_get_rdt_chunk(rtsp_t *rtsp_session, char **buffer, int rdt_rawdata) {

  int n=1;
  uint8_t header[8];
  rmff_pheader_t ph;
  int size;
  int flags1, flags2;
  int unknown1;
  uint32_t ts;
  static uint32_t prev_ts = -1;
  static int prev_stream_number = -1;

  n=rtsp_read_data(rtsp_session, header, 8);
  if (n<8) return 0;
  if (header[0] != 0x24)
  {