Add support for http, https, and file URLs.

This is pretty preliminary for now.
Seeking performance isn't great, and there's no caching.
I'm sure there's also lots of bugs.

examples/opusfile_example.c

@@ -38,19 +38,23 @@ int main(int _argc,const char **_argv){
     OpusFileCallbacks cb={NULL,NULL,NULL,NULL};
     of=op_open_callbacks(op_fdopen(&cb,fileno(stdin),"rb"),&cb,NULL,0,&ret);
   }
-#if 0
-  /*For debugging: force a file to not be seekable.*/
   else{
-    OpusFileCallbacks  cb={NULL,NULL,NULL,NULL};
-    void              *fp;
-    fp=op_fopen(&cb,_argv[1],"rb");
-    cb.seek=NULL;
-    cb.tell=NULL;
-    of=op_open_callbacks(fp,&cb,NULL,0,NULL);
-  }
+    /*Try to treat the argument as a URL.*/
+    of=op_open_url(_argv[1],OP_SSL_SKIP_CERTIFICATE_CHECK,&ret);
+#if 0
+    if(of==NULL){
+        OpusFileCallbacks  cb={NULL,NULL,NULL,NULL};
+        void              *fp;
+        /*For debugging: force a file to not be seekable.*/
+        fp=op_fopen(&cb,_argv[1],"rb");
+        cb.seek=NULL;
+        cb.tell=NULL;
+        of=op_open_callbacks(fp,&cb,NULL,0,NULL);
+      }
 #else
-  else of=op_open_file(_argv[1],&ret);
+    if(of==NULL)of=op_open_file(_argv[1],&ret);
 #endif
+  }
   if(of==NULL){
     fprintf(stderr,"Failed to open file '%s': %i\n",_argv[1],ret);
     return EXIT_FAILURE;

src/opusfile.c

@@ -1259,6 +1259,20 @@ OggOpusFile *op_open_memory(const unsigned char *_data,size_t _size,
    _error);
 }
 
+OggOpusFile *op_open_url(const char *_url,int _flags,int *_error){
+  OpusFileCallbacks cb;
+  return op_open_close_on_failure(
+   op_url_stream_create(&cb,_url,_flags),&cb,_error);
+}
+
+OggOpusFile *op_open_url_with_proxy(const char *_url,int _flags,
+ const char *_proxy_host,unsigned _proxy_port,
+ const char *_proxy_user,const char *_proxy_pass,int *_error){
+  OpusFileCallbacks cb;
+  return op_open_close_on_failure(op_url_stream_create_with_proxy(&cb,_url,
+   _flags,_proxy_host,_proxy_port,_proxy_pass,_proxy_user),&cb,_error);
+}
+
 /*Convenience routine to clean up from failure for the open functions that
    create their own streams.*/
 static OggOpusFile *op_test_close_on_failure(void *_source,
@@ -1285,6 +1299,20 @@ OggOpusFile *op_test_memory(const unsigned char *_data,size_t _size,
    _error);
 }
 
+OggOpusFile *op_test_url(const char *_url,int _flags,int *_error){
+  OpusFileCallbacks cb;
+  return op_test_close_on_failure(
+   op_url_stream_create(&cb,_url,_flags),&cb,_error);
+}
+
+OggOpusFile *op_test_url_with_proxy(const char *_url,int _flags,
+ const char *_proxy_host,unsigned _proxy_port,
+ const char *_proxy_user,const char *_proxy_pass,int *_error){
+  OpusFileCallbacks cb;
+  return op_test_close_on_failure(op_url_stream_create_with_proxy(&cb,_url,
+   _flags,_proxy_host,_proxy_port,_proxy_pass,_proxy_user),&cb,_error);
+}
+
 int op_test_open(OggOpusFile *_of){
   int ret;
   if(OP_UNLIKELY(_of->ready_state!=OP_PARTOPEN))return OP_EINVAL;

unix/Makefile

@@ -13,25 +13,36 @@ FOO_TARGET = foo
 # The command to use to generate dependency information
 MAKEDEPEND = ${CC} -MM
 #MAKEDEPEND = makedepend -f- -Y --
-# The location of include files.
-# Modify these to point to your Ogg and Vorbis include directories if they are
-#  not installed in a standard location.
-CINCLUDE = `pkg-config --cflags ogg opus`
-# These are gcc-only, but not actually critical.
+# Optional features to enable
+#CFLAGS := $(CFLAGS) -DOP_HAVE_LRINTF
+CFLAGS := $(CFLAGS) -DOP_ENABLE_HTTP
 # Extra compilation flags.
 # You may get speed increases by including flags such as -O2 or -O3 or
 #  -ffast-math, or additional flags, depending on your system and compiler.
 # The -g flag will generally include debugging information.
 CFLAGS := -g $(CFLAGS)
 CFLAGS := -DOP_ENABLE_ASSERTIONS $(CFLAGS)
+# These are gcc-only, but not actually critical.
 CFLAGS := -fPIC $(CFLAGS)
 CFLAGS := -std=c89 -pedantic $(CFLAGS)
 CFLAGS := -fvisibility=hidden $(CFLAGS)
 CFLAGS := -Wextra -Wno-parentheses -Wno-long-long $(CFLAGS)
 CFLAGS := -Wall $(CFLAGS)
+# The list of pkg-config packages we depend on.
+PACKAGES := ogg opus
+ifeq ($(findstring -DOP_ENABLE_HTTP,${CFLAGS}),-DOP_ENABLE_HTTP)
+PACKAGES += openssl
+endif
+# The location of include files.
+# Modify these to point to your Ogg and Vorbis include directories if they are
+#  not installed in a standard location.
+CINCLUDE := `pkg-config --cflags ${PACKAGES}`
 
 # Libraries to link with, and the location of library files.
-LIBS = `pkg-config --libs ogg opus`
+LIBS := `pkg-config --libs ${PACKAGES}`
+ifeq ($(findstring -DOP_HAVE_LRINTF,${CFLAGS}),-DOP_HAVE_LRINTF)
+LIBS := -lm $(LIBS)
+endif
 
 #TODO: tests
 FOO_LIBS =
@@ -45,6 +56,7 @@ WORKDIR = objs
 
 # C source file lists
 LIBOPUSFILE_CSOURCES = \
+http.c \
 info.c \
 internal.c \
 opusfile.c \