APE tag writer

libavformat/Makefile

@@ -357,7 +357,7 @@ OBJS-$(CONFIG_WTV_DEMUXER)               += wtvdec.o wtv.o asfdec.o asf.o asfcry
                                             avlanguage.o mpegts.o isom.o
 OBJS-$(CONFIG_WTV_MUXER)                 += wtvenc.o wtv.o asf.o asfenc.o
 OBJS-$(CONFIG_WV_DEMUXER)                += wv.o apetag.o img2.o
-OBJS-$(CONFIG_WV_MUXER)                  += wvenc.o
+OBJS-$(CONFIG_WV_MUXER)                  += wvenc.o apetagenc.o
 OBJS-$(CONFIG_XA_DEMUXER)                += xa.o
 OBJS-$(CONFIG_XBIN_DEMUXER)              += bintext.o sauce.o
 OBJS-$(CONFIG_XMV_DEMUXER)               += xmv.o

libavformat/apetag.h

@@ -30,4 +30,9 @@
  */
 void ff_ape_parse_tag(AVFormatContext *s);
 
+/**
+ * Write an APEv2 tag
+ */
+void ff_ape_write(AVFormatContext *s);
+
 #endif /* AVFORMAT_APETAG_H */

libavformat/apetagenc.c

@@ -0,0 +1,69 @@
+/*
+ * APE tag writer
+ * Copyright (c) 2012 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/dict.h"
+#include "avio_internal.h"
+#include "avformat.h"
+#include "apetag.h"
+
+#define APE_TAG_PREAMBLE        "APETAGEX"
+#define APE_TAG_VERSION         2000
+#define APE_TAG_FOOTER_BYTES    32
+
+static int string_is_ascii(const uint8_t *str)
+{
+    while (*str && *str >= 0x20 && *str <= 0x7e ) str++;
+    return !*str;
+}
+
+void ff_ape_write(AVFormatContext *s)
+{
+    int64_t tag_bytes;
+    AVDictionaryEntry *t = NULL;
+    AVIOContext *pb = s->pb;
+    int tags = 0, vlen;
+
+    tag_bytes = avio_tell(s->pb);
+    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
+        if (!string_is_ascii(t->key)) {
+            av_log(s, AV_LOG_WARNING, "Non ASCII keys are not allowed\n");
+            continue;
+        }
+
+        vlen = strlen(t->value);
+        avio_wl32(pb, vlen + 1);
+        avio_wl32(pb, 0); // flags
+        avio_put_str(pb, t->key);
+        avio_put_str(pb, t->value);
+        tags++;
+    }
+    tag_bytes = avio_tell(s->pb) - tag_bytes;
+
+    if (!tags)
+        return;
+
+    avio_write(pb, APE_TAG_PREAMBLE, 8);
+    avio_wl32(pb, APE_TAG_VERSION);
+    avio_wl32(pb, tag_bytes + APE_TAG_FOOTER_BYTES);
+    avio_wl32(pb, tags); // item count
+    avio_wl32(pb, 0); // global flags
+    ffio_fill(pb, 0, 8); // reserved
+}