mplayer: turn playtree into a list, and change per-file option handling

Summary:
- There is no playtree anymore. It's reduced to a simple list.
- Options are now always global. You can still have per-file options,
  but these are optional and require special syntax.
- The slave command pt_step has been removed, and playlist_next
  and playlist_prev added. (See etc/input.conf changes.)
  This is a user visible incompatible change, and will break slave-mode
  applications.
- The pt_clear slave command is renamed to playlist_clear.
- Playtree entries could have multiple files. This is not the case
  anymore, and playlist entries have always exactly one entry. Whenever
  something adds more than one file (like ASX playlists or dvd:// or
  dvdnav:// on the command line), all files are added as separate
  playlist entries.

Note that some of the changes are quite deep and violent. Expect
regressions.

The playlist parsing code in particular is of low quality. I didn't try
to improve it, and merely spent to least effort necessary to keep it
somehow working. (Especially ASX playlist handling.)

The playtree code was complicated and bloated. It was also barely used.
Most users don't even know that mplayer manages the playlist as tree,
or how to use it. The most obscure features was probably specifying a
tree on command line (with '{' and '}' to create/close tree nodes). It
filled the player code with complexity and confused users with weird
slave commands like pt_up.

Replace the playtree with a simple flat playlist. Playlist parsers that
actually return trees are changed to append all files to the playlist
pre-order.

It used to be the responsibility of the playtree code to change per-file
config options. Now this is done by the player core, and the playlist
code is free of such details.

Options are not per-file by default anymore. This was a very obscure and
complicated feature that confused even experienced users. Consider the
following command line:

    mplayer file1.mkv file2.mkv --no-audio file3.mkv

This will disable the audio for file2.mkv only, because options are
per-file by default. To make the option affect all files, you're
supposed to put it before the first file.

This is bad, because normally you don't need per-file options. They are
very rarely needed, and the only reasonable use cases I can imagine are
use of the encode backend (mplayer encode branch), or for debugging. The
normal use case is made harder, and the feature is perceived as bug.
Even worse, correct usage is hard to explain for users.

Make all options global by default. The position of an option isn't
significant anymore (except for options that compensate each other,
consider --shuffle --no-shuffle).

One other important change is that no options are reset anymore if a
new file is started. If you change settings with slave mode commands,
they will not be changed by playing a new file. (Exceptions include
settings that are too file specific, like audio/subtitle stream
selection.)

There is still some need for per-file options. Debugging and encoding
are use cases that profit from per-file options. Per-file profiles (as
well as per-protocol and per-VO/AO options) need the implementation
related mechanisms to backup and restore options when the playback file
changes.

Simplify the save-slot stuff, which is possible because there is no
hierarchical play tree anymore. Now there's a simple backup field.

Add a way to specify per-file options on command line. Example:

    mplayer f1.mkv -o0 --{ -o1 f2.mkv -o2 f3.mkv --} f4.mkv -o3

will have the following options per file set:

    f1.mkv, f4.mkv: -o0 -o3
    f2.mkv, f3.mkv: -o0 -o3 -o1 -o2

The options --{ and --} start and end per-file options. All files inside
the { } will be affected by the options equally (similar to how global
options and multiple files are handled). When playback of a file starts,
the per-file options are set according to the command line. When
playback ends, the per-file options are restored to the values when
playback started.

1 files changed, 780 insertions, 0 deletions

diff --git a/playlist_parser.c b/playlist_parser.c
new file mode 100644
index 0000000000..0edabc13b9
--- /dev/null
+++ b/playlist_parser.c
@@ -0,0 +1,780 @@
+/*
+ * This file is part of MPlayer.
+ *
+ * MPlayer 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.
+ *
+ * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <limits.h>
+
+#include "talloc.h"
+#include "asxparser.h"
+#include "m_config.h"
+#include "playlist.h"
+#include "playlist_parser.h"
+#include "stream/stream.h"
+#include "libmpdemux/demuxer.h"
+#include "mp_msg.h"
+#include "path.h"
+
+
+#define BUF_STEP 1024
+
+#define WHITES " \n\r\t"
+
+typedef struct play_tree_parser {
+  struct stream *stream;
+  char *buffer,*iter,*line;
+  int buffer_size , buffer_end;
+  int keep;
+  struct playlist *pl;
+} play_tree_parser_t;
+
+static void
+strstrip(char* str) {
+  char* i;
+
+  if (str==NULL)
+    return;
+  for(i = str ; i[0] != '\0' && strchr(WHITES,i[0]) != NULL; i++)
+    /* NOTHING */;
+  if(i[0] != '\0') {
+    memmove(str,i,strlen(i) + 1);
+    for(i = str + strlen(str) - 1 ; strchr(WHITES,i[0]) != NULL; i--)
+      /* NOTHING */;
+    i[1] = '\0';
+  } else
+    str[0] = '\0';
+}
+
+static char*
+play_tree_parser_get_line(play_tree_parser_t* p) {
+  char *end,*line_end;
+  int r,resize = 0;
+
+  if(p->buffer == NULL) {
+    p->buffer = malloc(BUF_STEP);
+    p->buffer_size = BUF_STEP;
+    p->buffer[0] = 0;
+    p->iter = p->buffer;
+  }
+
+  if(p->stream->eof && (p->buffer_end == 0 || p->iter[0] == '\0'))
+    return NULL;
+
+  assert(p->buffer_end < p->buffer_size);
+  assert(!p->buffer[p->buffer_end]);
+  while(1) {
+
+    if(resize) {
+      char *tmp;
+      r = p->iter - p->buffer;
+      end = p->buffer + p->buffer_end;
+      if (p->buffer_size > INT_MAX - BUF_STEP)
+        break;
+      tmp = realloc(p->buffer, p->buffer_size + BUF_STEP);
+      if (!tmp)
+        break;
+      p->buffer = tmp;
+      p->iter = p->buffer + r;
+      p->buffer_size += BUF_STEP;
+      resize = 0;
+    }
+
+    if(p->buffer_size - p->buffer_end > 1 && ! p->stream->eof) {
+      r = stream_read(p->stream,p->buffer + p->buffer_end,p->buffer_size - p->buffer_end - 1);
+      if(r > 0) {
+	p->buffer_end += r;
+	assert(p->buffer_end < p->buffer_size);
+	p->buffer[p->buffer_end] = '\0';
+	while(strlen(p->buffer + p->buffer_end - r) != r)
+	  p->buffer[p->buffer_end - r + strlen(p->buffer + p->buffer_end - r)] = '\n';
+      }
+      assert(!p->buffer[p->buffer_end]);
+    }
+
+    end = strchr(p->iter,'\n');
+    if(!end) {
+      if(p->stream->eof) {
+	end = p->buffer + p->buffer_end;
+	break;
+      }
+      resize = 1;
+      continue;
+    }
+    break;
+  }
+
+  line_end = (end > p->iter && *(end-1) == '\r') ? end-1 : end;
+  if(line_end - p->iter >= 0)
+    p->line = realloc(p->line, line_end - p->iter + 1);
+  else
+    return NULL;
+  if(line_end - p->iter > 0)
+    strncpy(p->line,p->iter,line_end - p->iter);
+  p->line[line_end - p->iter] = '\0';
+  if(end[0] != '\0')
+    end++;
+
+  if(!p->keep) {
+    if(end[0] != '\0') {
+      p->buffer_end -= end-p->iter;
+      memmove(p->buffer,end,p->buffer_end);
+    } else
+      p->buffer_end = 0;
+    p->buffer[p->buffer_end] = '\0';
+    p->iter = p->buffer;
+  } else
+    p->iter = end;
+
+  return p->line;
+}
+
+static void
+play_tree_parser_reset(play_tree_parser_t* p) {
+  p->iter = p->buffer;
+}
+
+static void
+play_tree_parser_stop_keeping(play_tree_parser_t* p) {
+  p->keep = 0;
+  if(p->iter && p->iter != p->buffer) {
+    p->buffer_end -= p->iter -p->buffer;
+    if(p->buffer_end)
+      memmove(p->buffer,p->iter,p->buffer_end);
+    p->buffer[p->buffer_end] = 0;
+    p->iter = p->buffer;
+  }
+}
+
+
+static bool parse_asx(play_tree_parser_t* p) {
+  int comments = 0,get_line = 1;
+  char* line = NULL;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying asx...\n");
+
+  while(1) {
+    if(get_line) {
+      line = play_tree_parser_get_line(p);
+      if(!line)
+	return false;
+      strstrip(line);
+      if(line[0] == '\0')
+	continue;
+    }
+    if(!comments) {
+      if(line[0] != '<') {
+	mp_msg(MSGT_PLAYTREE,MSGL_DBG2,"First char isn't '<' but '%c'\n",line[0]);
+	mp_msg(MSGT_PLAYTREE,MSGL_DBG3,"Buffer = [%s]\n",p->buffer);
+	return false;
+      } else if(strncmp(line,"<!--",4) == 0) { // Comments
+	comments = 1;
+	line += 4;
+	if(line[0] != '\0' && strlen(line) > 0)
+	  get_line = 0;
+      } else if(strncasecmp(line,"<ASX",4) == 0) // We got an asx element
+	break;
+      else // We don't get an asx
+	return false;
+    } else { // Comments
+      char* c;
+      c = strchr(line,'-');
+      if(c) {
+	if (strncmp(c,"--!>",4) == 0) { // End of comments
+	  comments = 0;
+	  line = c+4;
+	  if(line[0] != '\0') // There is some more data on this line : keep it
+	    get_line = 0;
+
+	} else {
+	  line = c+1; // Jump the -
+	  if(line[0] != '\0') // Some more data
+	    get_line = 0;
+	  else  // End of line
+	    get_line = 1;
+	}
+      } else // No - on this line (or rest of line) : get next one
+	get_line = 1;
+    }
+  }
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected asx format\n");
+
+  // We have an asx : load it in memory and parse
+
+  while((line = play_tree_parser_get_line(p)) != NULL)
+    /* NOTHING */;
+
+ mp_msg(MSGT_PLAYTREE,MSGL_DBG3,"Parsing asx file: [%s]\n",p->buffer);
+ return asx_parse(p->buffer,p->pl);
+}
+
+static char*
+pls_entry_get_value(char* line) {
+  char* i;
+
+  i = strchr(line,'=');
+  if(!i || i[1] == '\0')
+    return NULL;
+  else
+    return i+1;
+}
+
+typedef struct pls_entry {
+  char* file;
+  char* title;
+  char* length;
+} pls_entry_t;
+
+static int
+pls_read_entry(char* line,pls_entry_t** _e,int* _max_entry,char** val) {
+  int num,max_entry = (*_max_entry);
+  pls_entry_t* e = (*_e);
+  int limit = INT_MAX / sizeof(*e);
+  char* v;
+
+  v = pls_entry_get_value(line);
+  if(!v) {
+    mp_msg(MSGT_PLAYTREE,MSGL_ERR,"No value in entry %s\n",line);
+    return -1;
+  }
+
+  num = atoi(line);
+  if(num <= 0 || num > limit) {
+    if (max_entry >= limit) {
+        mp_msg(MSGT_PLAYTREE, MSGL_WARN, "Too many index entries\n");
+        return -1;
+    }
+    num = max_entry+1;
+    mp_msg(MSGT_PLAYTREE,MSGL_WARN,"No or invalid entry index in entry %s\nAssuming %d\n",line,num);
+  }
+  if(num > max_entry) {
+    e = realloc(e, num * sizeof(pls_entry_t));
+    if (!e)
+      return -1;
+    memset(&e[max_entry],0,(num-max_entry)*sizeof(pls_entry_t));
+    max_entry = num;
+  }
+  (*_e) = e;
+  (*_max_entry) = max_entry;
+  (*val) = v;
+
+  return num;
+}
+
+
+static bool parse_pls(play_tree_parser_t* p) {
+  char *line,*v;
+  pls_entry_t* entries = NULL;
+  int n_entries = 0,max_entry=0,num;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying Winamp playlist...\n");
+  while((line = play_tree_parser_get_line(p))) {
+    strstrip(line);
+    if(strlen(line))
+      break;
+  }
+  if (!line)
+    return false;
+  if(strcasecmp(line,"[playlist]"))
+    return false;
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected Winamp playlist format\n");
+  play_tree_parser_stop_keeping(p);
+  line = play_tree_parser_get_line(p);
+  if(!line)
+    return false;
+  strstrip(line);
+  if(strncasecmp(line,"NumberOfEntries",15) == 0) {
+    v = pls_entry_get_value(line);
+    n_entries = atoi(v);
+    if(n_entries < 0)
+      mp_msg(MSGT_PLAYTREE,MSGL_DBG2,"Invalid number of entries: very funny!!!\n");
+    else
+      mp_msg(MSGT_PLAYTREE,MSGL_DBG2,"Playlist claims to have %d entries. Let's see.\n",n_entries);
+    line = play_tree_parser_get_line(p);
+  }
+
+  while(line) {
+    strstrip(line);
+    if(line[0] == '\0') {
+      line = play_tree_parser_get_line(p);
+      continue;
+    }
+    if(strncasecmp(line,"File",4) == 0) {
+      num = pls_read_entry(line+4,&entries,&max_entry,&v);
+      if(num < 0)
+	mp_msg(MSGT_PLAYTREE,MSGL_ERR,"No value in entry %s\n",line);
+      else
+	entries[num-1].file = strdup(v);
+    } else if(strncasecmp(line,"Title",5) == 0) {
+      num = pls_read_entry(line+5,&entries,&max_entry,&v);
+      if(num < 0)
+	mp_msg(MSGT_PLAYTREE,MSGL_ERR,"No value in entry %s\n",line);
+      else
+	entries[num-1].title = strdup(v);
+    } else if(strncasecmp(line,"Length",6) == 0) {
+      num = pls_read_entry(line+6,&entries,&max_entry,&v);
+      if(num < 0)
+	mp_msg(MSGT_PLAYTREE,MSGL_ERR,"No value in entry %s\n",line);
+      else {
+        char *end;
+        long val = strtol(v, &end, 10);
+        if (*end || (val <= 0 && val != -1))
+          mp_msg(MSGT_PLAYTREE,MSGL_ERR,"Invalid length value in entry %s\n",line);
+        else if (val > 0)
+          entries[num-1].length = strdup(v);
+      }
+    } else
+      mp_msg(MSGT_PLAYTREE,MSGL_WARN,"Unknown entry type %s\n",line);
+    line = play_tree_parser_get_line(p);
+  }
+
+  for(num = 0; num < max_entry ; num++) {
+    if(entries[num].file == NULL)
+      mp_msg(MSGT_PLAYTREE,MSGL_ERR,"Entry %d don't have a file !!!!\n",num+1);
+    else {
+      mp_msg(MSGT_PLAYTREE,MSGL_DBG2,"Adding entry %s\n",entries[num].file);
+      playlist_add_file(p->pl,entries[num].file);
+      if (entries[num].length)
+          playlist_entry_add_param(p->pl->last,  bstr0("endpos"), bstr0(entries[num].length));
+      free(entries[num].file);
+    }
+    // When we have info in playtree we add these info
+    free(entries[num].title);
+    free(entries[num].length);
+  }
+
+  free(entries);
+  return true;
+}
+
+/*
+ Reference Ini-Format: Each entry is assumed a reference
+ */
+static bool parse_ref_ini(play_tree_parser_t* p) {
+  char *line,*v;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying reference-ini playlist...\n");
+  if (!(line = play_tree_parser_get_line(p)))
+    return NULL;
+  strstrip(line);
+  if(strcasecmp(line,"[Reference]"))
+    return NULL;
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected reference-ini playlist format\n");
+  play_tree_parser_stop_keeping(p);
+  line = play_tree_parser_get_line(p);
+  if(!line)
+    return NULL;
+  while(line) {
+    strstrip(line);
+    if(strncasecmp(line,"Ref",3) == 0) {
+      v = pls_entry_get_value(line+3);
+      if(!v)
+	mp_msg(MSGT_PLAYTREE,MSGL_ERR,"No value in entry %s\n",line);
+      else
+      {
+        mp_msg(MSGT_PLAYTREE,MSGL_DBG2,"Adding entry %s\n",v);
+        playlist_add_file(p->pl, v);
+      }
+    }
+    line = play_tree_parser_get_line(p);
+  }
+
+  return true;
+}
+
+static bool parse_m3u(play_tree_parser_t* p) {
+  char* line;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying extended m3u playlist...\n");
+  if (!(line = play_tree_parser_get_line(p)))
+    return NULL;
+  strstrip(line);
+  if(strcasecmp(line,"#EXTM3U"))
+    return NULL;
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected extended m3u playlist format\n");
+  play_tree_parser_stop_keeping(p);
+
+  while((line = play_tree_parser_get_line(p)) != NULL) {
+    strstrip(line);
+    if(line[0] == '\0')
+      continue;
+    /* EXTM3U files contain such lines:
+     * #EXTINF:<seconds>, <title>
+     * followed by a line with the filename
+     * for now we have no place to put that
+     * so we just skip that extra-info ::atmos
+     */
+    if(line[0] == '#') {
+#if 0 /* code functional */
+      if(strncasecmp(line,"#EXTINF:",8) == 0) {
+        mp_msg(MSGT_PLAYTREE,MSGL_INFO,"[M3U] Duration: %dsec  Title: %s\n",
+          strtol(line+8,&line,10), line+2);
+      }
+#endif
+      continue;
+    }
+    playlist_add_file(p->pl, line);
+  }
+
+  return true;
+}
+
+static bool parse_smil(play_tree_parser_t* p) {
+  int entrymode=0;
+  char* line,source[512],*pos,*s_start,*s_end,*src_line;
+  int is_rmsmil = 0;
+  unsigned int npkt, ttlpkt;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying smil playlist...\n");
+
+  // Check if smil
+  while((line = play_tree_parser_get_line(p)) != NULL) {
+    strstrip(line);
+    if(line[0] == '\0') // Ignore empties
+      continue;
+    if (strncasecmp(line,"<?xml",5)==0) // smil in xml
+      continue;
+    if (strncasecmp(line,"<!DOCTYPE smil",13)==0) // smil in xml
+      continue;
+    if (strncasecmp(line,"<smil",5)==0 || strncasecmp(line,"<?wpl",5)==0 ||
+      strncasecmp(line,"(smil-document",14)==0)
+      break; // smil header found
+    else
+      return NULL; //line not smil exit
+  }
+
+  if (!line) return NULL;
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected smil playlist format\n");
+  play_tree_parser_stop_keeping(p);
+
+  if (strncasecmp(line,"(smil-document",14)==0) {
+    mp_msg(MSGT_PLAYTREE,MSGL_V,"Special smil-over-realrtsp playlist header\n");
+    is_rmsmil = 1;
+    if (sscanf(line, "(smil-document (ver 1.0)(npkt %u)(ttlpkt %u", &npkt, &ttlpkt) != 2) {
+      mp_msg(MSGT_PLAYTREE,MSGL_WARN,"smil-over-realrtsp: header parsing failure, assuming single packet.\n");
+      npkt = ttlpkt = 1;
+    }
+    if (ttlpkt == 0 || npkt > ttlpkt) {
+      mp_msg(MSGT_PLAYTREE,MSGL_WARN,"smil-over-realrtsp: bad packet counters (npkk = %u, ttlpkt = %u), assuming single packet.\n",
+        npkt, ttlpkt);
+      npkt = ttlpkt = 1;
+    }
+  }
+
+  //Get entries from smil
+  src_line = line;
+  line = NULL;
+  do {
+    strstrip(src_line);
+    free(line);
+    line = NULL;
+    /* If we're parsing smil over realrtsp and this is not the last packet and
+     * this is the last line in the packet (terminating with ") ) we must get
+     * the next line, strip the header, and concatenate it to the current line.
+     */
+    if (is_rmsmil && npkt != ttlpkt && strstr(src_line,"\")")) {
+      char *payload;
+
+      line = strdup(src_line);
+      if(!(src_line = play_tree_parser_get_line(p))) {
+        mp_msg(MSGT_PLAYTREE,MSGL_WARN,"smil-over-realrtsp: can't get line from packet %u/%u.\n", npkt, ttlpkt);
+        break;
+      }
+      strstrip(src_line);
+      // Skip header, packet starts after "
+      if(!(payload = strchr(src_line,'\"'))) {
+        mp_msg(MSGT_PLAYTREE,MSGL_WARN,"smil-over-realrtsp: can't find start of packet, using complete line.\n");
+        payload = src_line;
+      } else
+        payload++;
+      // Skip ") at the end of the last line from the current packet
+      line[strlen(line)-2] = 0;
+      line = realloc(line, strlen(line)+strlen(payload)+1);
+      strcat (line, payload);
+      npkt++;
+    } else
+      line = strdup(src_line);
+    /* Unescape \" to " for smil-over-rtsp */
+    if (is_rmsmil && line[0] != '\0') {
+      int i, j;
+
+      for (i = 0; i < strlen(line); i++)
+        if (line[i] == '\\' && line[i+1] == '"')
+          for (j = i; line[j]; j++)
+            line[j] = line[j+1];
+    }
+    pos = line;
+   while (pos) {
+    if (!entrymode) { // all entries filled so far
+     while ((pos=strchr(pos, '<'))) {
+      if (strncasecmp(pos,"<video",6)==0  || strncasecmp(pos,"<audio",6)==0 || strncasecmp(pos,"<media",6)==0) {
+          entrymode=1;
+          break; // Got a valid tag, exit '<' search loop
+      }
+      pos++;
+     }
+    }
+    if (entrymode) { //Entry found but not yet filled
+      pos = strstr(pos,"src=");   // Is source present on this line
+      if (pos != NULL) {
+        entrymode=0;
+        if (pos[4] != '"' && pos[4] != '\'') {
+          mp_msg(MSGT_PLAYTREE,MSGL_V,"Unknown delimiter %c in source line %s\n", pos[4], line);
+          break;
+        }
+        s_start=pos+5;
+        s_end=strchr(s_start,pos[4]);
+        if (s_end == NULL) {
+          mp_msg(MSGT_PLAYTREE,MSGL_V,"Error parsing this source line %s\n",line);
+          break;
+        }
+        if (s_end-s_start> 511) {
+          mp_msg(MSGT_PLAYTREE,MSGL_V,"Cannot store such a large source %s\n",line);
+          break;
+        }
+        strncpy(source,s_start,s_end-s_start);
+        source[(s_end-s_start)]='\0'; // Null terminate
+        playlist_add_file(p->pl, source);
+        pos = s_end;
+      }
+    }
+   }
+  } while((src_line = play_tree_parser_get_line(p)) != NULL);
+
+  free(line);
+  return true;
+}
+
+static bool parse_textplain(play_tree_parser_t* p) {
+  char* line;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying plaintext playlist...\n");
+  play_tree_parser_stop_keeping(p);
+
+  while((line = play_tree_parser_get_line(p)) != NULL) {
+    strstrip(line);
+    if(line[0] == '\0' || line[0] == '#' || (line[0] == '/' && line[1] == '/'))
+      continue;
+
+      playlist_add_file(p->pl,line);
+  }
+
+  return true;
+}
+
+/**
+ * \brief decode the base64 used in nsc files
+ * \param in input string, 0-terminated
+ * \param buf output buffer, must point to memory suitable for realloc,
+ *            will be NULL on failure.
+ * \return decoded length in bytes
+ */
+static int decode_nsc_base64(char *in, char **buf) {
+  int i, j, n;
+  if (in[0] != '0' || in[1] != '2')
+    goto err_out;
+  in += 2; // skip prefix
+  if (strlen(in) < 16) // error out if nothing to decode
+    goto err_out;
+  in += 12; // skip encoded string length
+  n = strlen(in) / 4;
+  *buf = realloc(*buf, n * 3);
+  for (i = 0; i < n; i++) {
+    uint8_t c[4];
+    for (j = 0; j < 4; j++) {
+      c[j] = in[4 * i + j];
+      if (c[j] >= '0' && c[j] <= '9') c[j] += 0 - '0';
+      else if (c[j] >= 'A' && c[j] <= 'Z') c[j] += 10 - 'A';
+      else if (c[j] >= 'a' && c[j] <= 'z') c[j] += 36 - 'a';
+      else if (c[j] == '{') c[j] = 62;
+      else if (c[j] == '}') c[j] = 63;
+      else {
+        mp_msg(MSGT_PLAYTREE, MSGL_ERR, "Invalid character %c (0x%02"PRIx8")\n", c[j], c[j]);
+        goto err_out;
+      }
+    }
+    (*buf)[3 * i] = (c[0] << 2) | (c[1] >> 4);
+    (*buf)[3 * i + 1] = (c[1] << 4) | (c[2] >> 2);
+    (*buf)[3 * i + 2] = (c[2] << 6) | c[3];
+  }
+  return 3 * n;
+err_out:
+  free(*buf);
+  *buf = NULL;
+  return 0;
+}
+
+/**
+ * \brief "converts" utf16 to ascii by just discarding every second byte
+ * \param buf buffer to convert
+ * \param len lenght of buffer, must be > 0
+ */
+static void utf16_to_ascii(char *buf, int len) {
+  int i;
+  if (len <= 0) return;
+  for (i = 0; i < len / 2; i++)
+    buf[i] = buf[i * 2];
+  buf[i] = 0; // just in case
+}
+
+static bool parse_nsc(play_tree_parser_t* p) {
+  char *line, *addr = NULL, *url, *unicast_url = NULL;
+  int port = 0;
+
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Trying nsc playlist...\n");
+  while((line = play_tree_parser_get_line(p)) != NULL) {
+    strstrip(line);
+    if(!line[0]) // Ignore empties
+      continue;
+    if (strncasecmp(line,"[Address]", 9) == 0)
+      break; // nsc header found
+    else
+      return false;
+  }
+  mp_msg(MSGT_PLAYTREE,MSGL_V,"Detected nsc playlist format\n");
+  play_tree_parser_stop_keeping(p);
+  while ((line = play_tree_parser_get_line(p)) != NULL) {
+    strstrip(line);
+    if (!line[0])
+      continue;
+    if (strncasecmp(line, "Unicast URL=", 12) == 0) {
+      int len = decode_nsc_base64(&line[12], &unicast_url);
+      if (len <= 0)
+        mp_msg(MSGT_PLAYTREE, MSGL_WARN, "[nsc] Unsupported Unicast URL encoding\n");
+      else
+        utf16_to_ascii(unicast_url, len);
+    } else if (strncasecmp(line, "IP Address=", 11) == 0) {
+      int len = decode_nsc_base64(&line[11], &addr);
+      if (len <= 0)
+        mp_msg(MSGT_PLAYTREE, MSGL_WARN, "[nsc] Unsupported IP Address encoding\n");
+      else
+        utf16_to_ascii(addr, len);
+    } else if (strncasecmp(line, "IP Port=", 8) == 0) {
+      port = strtol(&line[8], NULL, 0);
+    }
+  }
+
+  bool success = false;
+
+  if (unicast_url)
+    url = strdup(unicast_url);
+  else if (addr && port) {
+    url = malloc(strlen(addr) + 7 + 20 + 1);
+    sprintf(url, "http://%s:%i", addr, port);
+  } else
+   goto err_out;
+
+  playlist_add_file(p->pl, url);
+  free(url);
+  success = true;
+err_out:
+  free(addr);
+  free(unicast_url);
+  return success;
+}
+
+struct playlist *playlist_parse_file(const char *file)
+{
+  stream_t *stream;
+  int f=DEMUXER_TYPE_PLAYLIST;
+
+  stream = open_stream(file, 0, &f);
+  if(!stream) {
+      mp_msg(MSGT_PLAYTREE,MSGL_ERR,
+             "Error while opening playlist file %s: %s\n",
+             file, strerror(errno));
+    return false;
+  }
+
+  mp_msg(MSGT_PLAYTREE, MSGL_V,
+         "Parsing playlist file %s...\n", file);
+
+  struct playlist *ret = playlist_parse(stream);
+  free_stream(stream);
+
+  playlist_add_base_path(ret, mp_dirname(file));
+
+  return ret;
+
+}
+
+typedef bool (*parser_fn)(play_tree_parser_t *);
+static const parser_fn pl_parsers[] = {
+    parse_asx,
+    parse_pls,
+    parse_m3u,
+    parse_ref_ini,
+    parse_smil,
+    parse_nsc,
+    parse_textplain
+};
+
+
+static struct playlist *do_parse(struct stream* stream, bool forced)
+{
+  play_tree_parser_t p = {
+      .stream = stream,
+      .pl = talloc_zero(NULL, struct playlist),
+      .keep = 1,
+  };
+
+  bool success = false;
+  if (play_tree_parser_get_line(&p) != NULL) {
+    for (int n = 0; n < sizeof(pl_parsers) / sizeof(pl_parsers[0]); n++) {
+      play_tree_parser_reset(&p);
+      if (pl_parsers[n] == parse_textplain && !forced)
+        break;
+      if (pl_parsers[n](&p)) {
+        success = true;
+        break;
+      }
+    }
+  }
+
+  if(success)
+    mp_msg(MSGT_PLAYTREE,MSGL_V,"Playlist successfully parsed\n");
+  else {
+    mp_msg(MSGT_PLAYTREE,((forced==1)?MSGL_ERR:MSGL_V),"Error while parsing playlist\n");
+    talloc_free(p.pl);
+    p.pl = NULL;
+  }
+
+  if (p.pl && !p.pl->first)
+    mp_msg(MSGT_PLAYTREE,((forced==1)?MSGL_WARN:MSGL_V),"Warning: empty playlist\n");
+
+  return p.pl;
+}
+
+struct playlist *playlist_parse(struct stream* stream)
+{
+    return do_parse(stream, true);
+}
+
+struct playlist *playlist_probe_and_parse(struct stream* stream)
+{
+    return do_parse(stream, false);
+}