add tool for stripping tags

diff --git a/strip-tags.cc b/strip-tags.cc
new file mode 100644 (file)
index 0000000..7a4d8f9
--- /dev/null
+++ b/strip-tags.cc
@@ -0,0 +1,105 @@
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <set>
+
+#include <id3v2tag.h>
+#include <mpegfile.h>
+
+// set::find didn't work...?!
+class ByteVectorSet {
+public:
+    ByteVectorSet(set<TagLib::ByteVector *> bv_set)
+        : set_(bv_set)
+        { }
+
+    bool has(TagLib::ByteVector *bv) {
+        for (set<TagLib::ByteVector *>::const_iterator it = set_.begin();
+             it != set_.end();
+             ++it) {
+            if (**it == *bv) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+private:
+    set<TagLib::ByteVector *> set_;
+};
+
+static bool
+strip_frames(TagLib::MPEG::File &f, ByteVectorSet &preserve)
+{
+    TagLib::ID3v2::Tag *tag = f.ID3v2Tag();
+    if (tag == 0) {
+        return false;
+    }
+
+    bool stripped = false;
+    TagLib::ID3v2::FrameList frames = tag->frameList();
+    TagLib::ID3v2::FrameList::ConstIterator it;
+    for (it = frames.begin();
+         it != frames.end();
+         ++it) {
+        TagLib::ByteVector frameid = (*it)->frameID();
+        uint frameid_size = frameid.size();
+        char *frameid_s = new char[frameid_size + 1];
+        memcpy(frameid_s, frameid.data(), frameid_size);
+        frameid_s[frameid_size] = '\0';
+        printf("%s: %s ", frameid_s, (*it)->toString().toCString());
+        if (preserve.has(&frameid)) {
+            puts("preserve");
+            continue;
+        }
+        puts("remove");
+        delete[] frameid_s;
+        tag->removeFrame(*it, true);
+        stripped = true;
+
+    }
+    return stripped;
+}
+
+int
+main(int argc, char **argv)
+{
+    set<TagLib::ByteVector *> preserve_frames;
+
+    int c;
+    while ((c = getopt(argc, argv, "p:")) != -1) {
+        switch (c) {
+        case 'p':
+            preserve_frames.insert(new TagLib::ByteVector(optarg));
+            break;
+        default:
+            // getopt printed an error.
+            return 2;
+        }
+    }
+    argc -= optind; argv += optind;
+
+    ByteVectorSet preserve_frame_set(preserve_frames);
+
+    for (int i = 0; i < argc; ++i) {
+        const char *mp3_path = argv[i];
+        TagLib::MPEG::File f(mp3_path);
+        if (!strip_frames(f, preserve_frame_set)) {
+            continue;
+        }
+        errno = 0;
+        if (!f.save()) {
+            if (errno != 0) {
+                fprintf(stderr, "failed to save %s: %s\n",
+                        mp3_path, strerror(errno));
+            } else {
+                fprintf(stderr,  "failed to save %s\n", mp3_path);
+            }
+            return 3;
+        }
+    }
+
+    return 0;
+}