Work on JSON based format descriptions

spa/tests/meson.build

@@ -39,3 +39,8 @@ executable('test-props2', 'test-props2.c',
            dependencies : [],
            link_with : spalib,
            install : false)
+executable('test-props3', 'test-props3.c',
+           include_directories : [spa_inc, spa_libinc ],
+           dependencies : [],
+           link_with : spalib,
+           install : false)

spa/tests/test-props.c

@@ -99,6 +99,55 @@ key:       "<name>"
 
   "framerate": [ "25/1", "30/1" ] }
 
+* JSON based format description
+
+ [ <type>,
+   [ <media-type>, <media-subtype> ],
+   {
+     <key> : [ <type>, <value>, [ <value>, ... ] ],
+     ...
+   }
+ ]
+
+   <type> = "123.."
+
+   1: s = string    :  "value"
+      i = int       :  <number>
+      f = float     :  <float>
+      b = bool      :  true | false
+      R = rectangle : [ <width>, <height> ]
+      F = fraction  : [ <num>, <denom> ]
+
+   2: - = default (only default value present)
+      e = enum	        : [ <value>, ... ]
+      f = flags	        : [ <number> ]
+      m = min/max	: [ <min>, <max> ]
+      s = min/max/step  : [ <min>, <max>, <step> ]
+
+   3: u = unset		: value is unset, choose from options or default
+      o = optional	: value does not need to be set
+      r = readonly      : value is read only
+      d = deprecated    : value is deprecated
+
+[ "Format",
+  [ "video", "raw"],
+  {
+    "format" :    [ "se", "I420", [ "I420", "YUY2" ] ],
+    "size" :      [ "Rmu", [320, 240], [[ 640, 480], [1024,786]]],
+    "framerate" : [ "Fsu", [25, 1], [[ 0, 1], [65536,1]]]"
+  }
+]
+
+[ "Format",
+  [ "audio", "raw"],
+  {
+    "format" :      [ "se", "S16LE", [ "F32LE", "S16LE" ] ],
+    "rate" :        [ "imu", 44100, [8000, 96000]],
+    "channels" :    [ "imu", 1, [1, 4096]]"
+    "interleaved" : [ "beo", true ]"
+  }
+]
+
 spa_build(SPA_MEDIA_TYPE_VIDEO, SPA_MEDIA_SUBTYPE_RAW,
 	  type.format_video.format, SPA_PROP_TYPE_ID,
 	  video_format.I420

spa/tests/test-props3.c

@@ -0,0 +1,298 @@
+/* Spa
+ * Copyright (C) 2017 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <spa/type-map.h>
+#include <spa/type-map-impl.h>
+#include <spa/log.h>
+#include <spa/node.h>
+#include <spa/loop.h>
+#include <spa/video/format-utils.h>
+#include <spa/format-builder.h>
+
+#include <lib/debug.h>
+
+#if 0
+/*
+* JSON based format description
+
+ [ <type>,
+   [ <media-type>, <media-subtype> ],
+   {
+     <key> : [ <type>, <value>, [ <value>, ... ] ],
+     ...
+   }
+ ]
+
+   <type> = "123.."
+
+   1: s = string    :  "value"
+      i = int       :  <number>
+      f = float     :  <float>
+      b = bool      :  true | false
+      R = rectangle : [ <width>, <height> ]
+      F = fraction  : [ <num>, <denom> ]
+
+   2: - = default (only default value present)
+      e = enum	        : [ <value>, ... ]
+      f = flags	        : [ <number> ]
+      r = min/max	: [ <min>, <max> ]
+      s = min/max/step  : [ <min>, <max>, <step> ]
+
+   3: u = unset		: value is unset, choose from options or default
+      o = optional	: value does not need to be set
+      r = readonly      : value is read only
+      d = deprecated    : value is deprecated
+
+[ "Format",
+  [ "video", "raw"],
+  {
+    "format" :    [ "se", "I420", [ "I420", "YUY2" ] ],
+    "size" :      [ "Rru", [320, 240], [[ 640, 480], [1024,786]]],
+    "framerate" : [ "Fsu", [25, 1], [[ 0, 1], [65536,1]]]"
+  }
+]
+
+[ "Format",
+  [ "audio", "raw"],
+  {
+    "format" :      [ "se", "S16LE", [ "F32LE", "S16LE" ] ],
+    "rate" :        [ "iru", 44100, [8000, 96000]],
+    "channels" :    [ "iru", 1, [1, 4096]]"
+    "interleaved" : [ "beo", true ]"
+  }
+]
+*/
+#endif
+
+#include <stddef.h>
+
+struct spa_json_iter {
+  const char *cur;
+  const char *end;
+  struct spa_json_iter *parent;
+  int state;
+  int depth;
+};
+
+#define NONE      0
+#define STRUCT    1
+#define BARE      2
+#define STRING    3
+#define UTF8      4
+#define ESC       5
+
+static void
+spa_json_iter_init (struct spa_json_iter *iter, const char *data, size_t size)
+{
+  iter->end = data + size;
+  iter->parent = NULL;
+  iter->cur = data;
+  iter->state = NONE;
+}
+
+static int
+spa_json_iter_next (struct spa_json_iter *iter, const char **value)
+{
+  int utf8_remain = 0;
+
+  for (;iter->cur < iter->end; iter->cur++) {
+    unsigned char cur = (unsigned char) *iter->cur;
+again:
+    switch (iter->state) {
+      case NONE:
+        iter->state = STRUCT;
+        iter->depth = 0;
+        goto again;
+      case STRUCT:
+        switch (cur) {
+          case '\t': case ' ': case '\r': case '\n': case ':': case ',':
+            continue;
+          case '"':
+            *value = iter->cur;
+            iter->state = STRING;
+            continue;
+          case '[': case '{':
+            *value = iter->cur;
+            if (++iter->depth > 1)
+              continue;
+            iter->cur++;
+            return 1;
+          case '}': case ']':
+            if (iter->depth == 0) {
+              if (iter->parent)
+                iter->parent->cur = iter->cur;
+              return 0;
+            }
+            --iter->depth;
+            continue;
+          case '-': case 'a' ... 'z': case 'A' ... 'Z': case '0' ... '9':
+            *value = iter->cur;
+            iter->state = BARE;
+            continue;
+        }
+        return -1;
+      case BARE:
+        switch (cur) {
+          case '\t': case ' ': case '\r': case '\n': case ':': case ',':
+          case ']': case '}':
+            iter->state = STRUCT;
+            if (iter->depth > 0)
+              goto again;
+            return iter->cur - *value;
+          default:
+            if (cur >= 32 && cur <= 126)
+              continue;
+        }
+        return -1;
+      case STRING:
+        switch (cur) {
+          case '\\':
+            iter->state = ESC;
+            continue;
+          case '"':
+            iter->state = STRUCT;
+            if (iter->depth > 0)
+              continue;
+            iter->cur++;
+            return iter->cur - *value;
+          case 240 ... 247:
+            utf8_remain++;
+          case 224 ... 239:
+            utf8_remain++;
+          case 192 ... 223:
+            utf8_remain++;
+            iter->state = UTF8;
+            continue;
+          default:
+            if (cur >= 32 && cur <= 126)
+              continue;
+        }
+        return -1;
+      case UTF8:
+        switch (cur) {
+          case 128 ... 191:
+            if (--utf8_remain == 0)
+              iter->state = STRING;
+            continue;
+        }
+        return -1;
+      case ESC:
+        switch (cur) {
+          case '"': case '\\': case '/': case 'b': case 'f': case 'n': case 'r':
+          case 't': case 'u':
+            iter->state = STRING;
+            continue;
+        }
+        return -1;
+    }
+  }
+  return iter->depth == 0 ? 0 : -1;
+}
+
+static void
+spa_json_iter_enter (struct spa_json_iter *iter, struct spa_json_iter *sub)
+{
+  sub->end = iter->end;
+  sub->parent = iter;
+  sub->cur = iter->cur;
+  sub->state = NONE;
+}
+
+static int test_parsing(const char *format)
+{
+	struct spa_json_iter iter[5];
+	const char *value;
+	int len;
+
+	spa_json_iter_init (&iter[0], format, strlen(format));
+
+	if ((len = spa_json_iter_next(&iter[0], &value)) < 0) return len;
+	if (*value != '[') return -1;
+	spa_json_iter_enter(&iter[0], &iter[1]);
+
+	if ((len = spa_json_iter_next(&iter[1], &value)) < 0) return len;
+	if (*value != '"') return -1;
+
+	printf("Type: %.*s\n", len, value);
+
+	if ((len = spa_json_iter_next(&iter[1], &value)) < 0) return len;
+	if (*value != '[') return -1;
+	spa_json_iter_enter(&iter[1], &iter[2]);
+
+	if ((len = spa_json_iter_next(&iter[2], &value)) < 0) return len;
+	if (*value != '"') return -1;
+	printf("Media Type: %.*s\n", len, value);
+
+	if ((len = spa_json_iter_next(&iter[2], &value)) < 0) return len;
+	if (*value != '"') return -1;
+	printf("Media SubType: %.*s\n", len, value);
+
+	if ((len = spa_json_iter_next(&iter[1], &value)) < 0) return len;
+	if (*value != '{') return -1;
+	spa_json_iter_enter(&iter[1], &iter[2]);
+
+	while ((len = spa_json_iter_next(&iter[2], &value)) > 0) {
+		if (*value != '"') return -1;
+		printf("Key: %.*s\n", len, value);
+
+		if ((len = spa_json_iter_next(&iter[2], &value)) < 0) return len;
+		if (*value != '[') return -1;
+		spa_json_iter_enter(&iter[2], &iter[3]);
+
+		if ((len = spa_json_iter_next(&iter[3], &value)) < 0) return len;
+		printf("flags: %.*s\n", len, value);
+
+		if ((len = spa_json_iter_next(&iter[3], &value)) < 0) return len;
+		printf("default: %.*s\n", len, value);
+
+		if ((len = spa_json_iter_next(&iter[3], &value)) < 0) return len;
+		if (*value != '[') return -1;
+		spa_json_iter_enter(&iter[3], &iter[4]);
+
+		while ((len = spa_json_iter_next(&iter[4], &value)) > 0) {
+			printf("value: %.*s\n", len, value);
+		}
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	const char *format =
+		"[ \"Format\", "
+		"  [ \"audio\", \"raw\"], "
+		"  { "
+		"    \"format\":      [ \"se\", \"S16LE\", [ \"F32LE\", \"S16LE\" ]], "
+		"    \"rate\":        [ \"iru\", 44100, [8000, 96000]],"
+		"    \"channels\":    [ \"iru\", 1, [1, 4096]]"
+		"    \"interleaved\": [ \"beo\", true ]"
+		"  }"
+		"]";
+
+	test_parsing(format);
+
+	return 0;
+}