commit 7f181eb8b673aeb78551832e20102d0021ef3ab5
Author: nedko <nedko@internedko.net>
Date:   Fri Nov 25 16:12:57 2022 +0200

    Initial commit of old code

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..7dacfc2
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+all:
+	gcc -o flac_scan main.c
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..0a3b7fc
--- /dev/null
+++ b/main.c
@@ -0,0 +1,189 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#define THRESHOLD 1200
+
+/* portions derived from IJG code */
+
+#define readbyte(a,b) do if(((a)=getc((b))) == EOF) return 0; while (0)
+#define readword(a,b) do { int cc_=0,dd_=0; \
+                          if((cc_=getc((b))) == EOF \
+        		  || (dd_=getc((b))) == EOF) return 0; \
+                          (a) = (cc_<<8) + (dd_); \
+                          } while(0)
+
+
+int scanhead (FILE * infile, int * image_width, int * image_height) {
+  int marker=0;
+  int dummy=0;
+  if ( getc(infile) != 0xFF || getc(infile) != 0xD8 )
+    return 0;
+
+  for (;
+      ;) {
+
+
+    int discarded_bytes=0;
+    readbyte(marker,infile);
+    while (marker != 0xFF) {
+      discarded_bytes++;
+      readbyte(marker,infile);
+    }
+    do readbyte(marker,infile); while (marker == 0xFF);
+
+    if (discarded_bytes != 0) return 0;
+
+    switch (marker) {
+    case 0xC0:
+    case 0xC1:
+    case 0xC2:
+    case 0xC3:
+    case 0xC5:
+    case 0xC6:
+    case 0xC7:
+    case 0xC9:
+    case 0xCA:
+    case 0xCB:
+    case 0xCD:
+    case 0xCE:
+    case 0xCF: {
+      readword(dummy,infile);	/* usual parameter length count */
+      readbyte(dummy,infile);
+      readword((*image_height),infile);
+      readword((*image_width),infile);
+      readbyte(dummy,infile);
+
+      return 1;
+      break;
+      }
+    case 0xDA:
+    case 0xD9:
+      return 0;
+    default: {
+	int length;
+
+	readword(length,infile);
+
+	if (length < 2)
+	  return 0;
+	length -= 2;
+	while (length > 0) {
+	  readbyte(dummy, infile);
+	  length--;
+	}
+      }
+      break;
+    }
+  }
+}
+
+int scanPNG(FILE *fp, int *width, int *height)
+{
+	uint8_t img_buf[4];
+	uint32_t w;
+	uint32_t h;
+
+	// NO SEEKING IN PIPE
+	// fseek(fp, 16, SEEK_SET);
+	fread(img_buf, 1, 4, fp);
+	fread(img_buf, 1, 4, fp);
+	fread(img_buf, 1, 4, fp);
+	fread(img_buf, 1, 4, fp);
+
+	// Read Width
+	fread(img_buf, 1, 4, fp);
+	w = img_buf[0];
+	w <<= 8;
+	w += img_buf[1];
+	w <<= 8;
+	w += img_buf[2];
+	w <<= 8;
+	w += img_buf[3];
+
+	// Read Height
+	fread(img_buf, 1, 4, fp);
+	h = img_buf[0];
+	h <<= 8;
+	h += img_buf[1];
+	h <<= 8;
+	h += img_buf[2];
+	h <<= 8;
+	h += img_buf[3];
+
+	*width = w;
+	*height = h;
+	return 0;
+}
+
+int fpeek(FILE *stream)
+{
+    int c;
+
+	if (feof(stream))
+	{
+		return EOF;
+	}
+    c = fgetc(stream);
+    ungetc(c, stream);
+
+    return c;
+}
+
+int main(int argc, char **argv)
+{
+	int width;
+	int height;
+	int peek;
+	FILE *pp;
+	char cmd[2048];
+
+	if (argc < 2)
+	{
+		printf("Need filename\n");
+		return -1;
+	}
+
+	strcpy(cmd, "metaflac --export-picture-to=- \"");
+	strcat(cmd, argv[1]);
+	strcat(cmd, "\" 2>&1");
+
+	pp = popen(cmd, "r");
+	if (NULL == pp)
+	{
+		printf("Bad PP: '%s'\n", argv[1]);
+		return -1;
+	}
+
+	peek = fpeek(pp);
+	switch (peek)
+	{
+	case 0xFF:
+		//JPG
+		scanhead(pp, &width, &height);
+		if ((width > THRESHOLD) || (height > THRESHOLD))
+		{
+			printf("'%s' W:%04d H:%04d\n", argv[1], width, height);
+		}
+		break;
+
+	case 0x89:
+		//PNG
+		scanPNG(pp, &width, &height);
+		if ((width > THRESHOLD) || (height > THRESHOLD))
+		{
+			printf("'%s' W:%04d H:%04d\n", argv[1], width, height);
+		}
+		break;
+
+	case 0x2F:
+		break;
+
+	default:
+		//NaN
+		printf("'%s' WeirdChamp: 0x%02X\n", argv[1], peek);
+	}
+	pclose(pp);
+
+	return 0;
+}