Move id3v2 tag writing to a separate file.

Signed-off-by: Diego Biurrun <diego@biurrun.de>

4 files changed, 159 insertions, 113 deletions

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 6973b15995..903b3ee9ce 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -133,7 +133,7 @@ OBJS-$(CONFIG_MOV_MUXER)                 += movenc.o riff.o isom.o avc.o \
                                             movenchint.o rtpenc_chain.o
 OBJS-$(CONFIG_MP2_MUXER)                 += mp3enc.o rawenc.o
 OBJS-$(CONFIG_MP3_DEMUXER)               += mp3dec.o
-OBJS-$(CONFIG_MP3_MUXER)                 += mp3enc.o rawenc.o
+OBJS-$(CONFIG_MP3_MUXER)                 += mp3enc.o rawenc.o id3v2enc.o
 OBJS-$(CONFIG_MPC_DEMUXER)               += mpc.o apetag.o
 OBJS-$(CONFIG_MPC8_DEMUXER)              += mpc8.o
 OBJS-$(CONFIG_MPEG1SYSTEM_MUXER)         += mpegenc.o
diff --git a/libavformat/id3v2.h b/libavformat/id3v2.h
index b5e4894ea3..a296e0315b 100644
--- a/libavformat/id3v2.h
+++ b/libavformat/id3v2.h
@@ -87,6 +87,14 @@ void ff_id3v2_read(AVFormatContext *s, const char *magic);
 void ff_id3v2_read_all(AVFormatContext *s, const char *magic, ID3v2ExtraMeta **extra_meta);
 
 /**
+ * Write an ID3v2 tag.
+ * @param id3v2_version Subversion of ID3v2; supported values are 3 and 4
+ * @param magic magic bytes to identify the header
+ * If in doubt, use ID3v2_DEFAULT_MAGIC.
+ */
+int ff_id3v2_write(struct AVFormatContext *s, int id3v2_version, const char *magic);
+
+/**
  * Free memory allocated parsing special (non-text) metadata.
  * @param extra_meta Pointer to a pointer to the head of a ID3v2ExtraMeta list, *extra_meta is set to NULL.
  */
diff --git a/libavformat/id3v2enc.c b/libavformat/id3v2enc.c
new file mode 100644
index 0000000000..36c73bfecb
--- /dev/null
+++ b/libavformat/id3v2enc.c
@@ -0,0 +1,146 @@
+/*
+ * ID3v2 header writer
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+
+#include "libavutil/dict.h"
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+#include "avio.h"
+#include "id3v2.h"
+
+static void id3v2_put_size(AVFormatContext *s, int size)
+{
+    avio_w8(s->pb, size >> 21 & 0x7f);
+    avio_w8(s->pb, size >> 14 & 0x7f);
+    avio_w8(s->pb, size >> 7  & 0x7f);
+    avio_w8(s->pb, size       & 0x7f);
+}
+
+static int string_is_ascii(const uint8_t *str)
+{
+    while (*str && *str < 128) str++;
+    return !*str;
+}
+
+/**
+ * Write a text frame with one (normal frames) or two (TXXX frames) strings
+ * according to encoding (only UTF-8 or UTF-16+BOM supported).
+ * @return number of bytes written or a negative error code.
+ */
+static int id3v2_put_ttag(AVFormatContext *s, const char *str1, const char *str2,
+                          uint32_t tag, enum ID3v2Encoding enc)
+{
+    int len;
+    uint8_t *pb;
+    int (*put)(AVIOContext*, const char*);
+    AVIOContext *dyn_buf;
+    if (avio_open_dyn_buf(&dyn_buf) < 0)
+        return AVERROR(ENOMEM);
+
+    /* check if the strings are ASCII-only and use UTF16 only if
+     * they're not */
+    if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
+        (!str2 || string_is_ascii(str2)))
+        enc = ID3v2_ENCODING_ISO8859;
+
+    avio_w8(dyn_buf, enc);
+    if (enc == ID3v2_ENCODING_UTF16BOM) {
+        avio_wl16(dyn_buf, 0xFEFF);      /* BOM */
+        put = avio_put_str16le;
+    } else
+        put = avio_put_str;
+
+    put(dyn_buf, str1);
+    if (str2)
+        put(dyn_buf, str2);
+    len = avio_close_dyn_buf(dyn_buf, &pb);
+
+    avio_wb32(s->pb, tag);
+    id3v2_put_size(s, len);
+    avio_wb16(s->pb, 0);
+    avio_write(s->pb, pb, len);
+
+    av_freep(&pb);
+    return len + ID3v2_HEADER_SIZE;
+}
+
+static int id3v2_check_write_tag(AVFormatContext *s, AVDictionaryEntry *t, const char table[][4],
+                                 enum ID3v2Encoding enc)
+{
+    uint32_t tag;
+    int i;
+
+    if (t->key[0] != 'T' || strlen(t->key) != 4)
+        return -1;
+    tag = AV_RB32(t->key);
+    for (i = 0; *table[i]; i++)
+        if (tag == AV_RB32(table[i]))
+            return id3v2_put_ttag(s, t->value, NULL, tag, enc);
+    return -1;
+}
+
+int ff_id3v2_write(struct AVFormatContext *s, int id3v2_version,
+                   const char *magic)
+{
+    int64_t size_pos, cur_pos;
+    AVDictionaryEntry *t = NULL;
+
+    int totlen = 0, enc = id3v2_version == 3 ? ID3v2_ENCODING_UTF16BOM :
+                                               ID3v2_ENCODING_UTF8;
+
+
+    avio_wb32(s->pb, MKBETAG(magic[0], magic[1], magic[2], id3v2_version));
+    avio_w8(s->pb, 0);
+    avio_w8(s->pb, 0); /* flags */
+
+    /* reserve space for size */
+    size_pos = avio_tell(s->pb);
+    avio_wb32(s->pb, 0);
+
+    ff_metadata_conv(&s->metadata, ff_id3v2_34_metadata_conv, NULL);
+    if (id3v2_version == 4)
+        ff_metadata_conv(&s->metadata, ff_id3v2_4_metadata_conv, NULL);
+
+    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
+        int ret;
+
+        if ((ret = id3v2_check_write_tag(s, t, ff_id3v2_tags, enc)) > 0) {
+            totlen += ret;
+            continue;
+        }
+        if ((ret = id3v2_check_write_tag(s, t, id3v2_version == 3 ?
+                                               ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
+            totlen += ret;
+            continue;
+        }
+
+        /* unknown tag, write as TXXX frame */
+        if ((ret = id3v2_put_ttag(s, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
+            return ret;
+        totlen += ret;
+    }
+
+    cur_pos = avio_tell(s->pb);
+    avio_seek(s->pb, size_pos, SEEK_SET);
+    id3v2_put_size(s, totlen);
+    avio_seek(s->pb, cur_pos, SEEK_SET);
+    return 0;
+}
diff --git a/libavformat/mp3enc.c b/libavformat/mp3enc.c
index 64f8957a4c..e3c0987b6e 100644
--- a/libavformat/mp3enc.c
+++ b/libavformat/mp3enc.c
@@ -74,64 +74,6 @@ static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
     return count;
 }
 
-/* simple formats */
-
-static void id3v2_put_size(AVFormatContext *s, int size)
-{
-    avio_w8(s->pb, size >> 21 & 0x7f);
-    avio_w8(s->pb, size >> 14 & 0x7f);
-    avio_w8(s->pb, size >> 7  & 0x7f);
-    avio_w8(s->pb, size       & 0x7f);
-}
-
-static int string_is_ascii(const uint8_t *str)
-{
-    while (*str && *str < 128) str++;
-    return !*str;
-}
-
-/**
- * Write a text frame with one (normal frames) or two (TXXX frames) strings
- * according to encoding (only UTF-8 or UTF-16+BOM supported).
- * @return number of bytes written or a negative error code.
- */
-static int id3v2_put_ttag(AVFormatContext *s, const char *str1, const char *str2,
-                          uint32_t tag, enum ID3v2Encoding enc)
-{
-    int len;
-    uint8_t *pb;
-    int (*put)(AVIOContext*, const char*);
-    AVIOContext *dyn_buf;
-    if (avio_open_dyn_buf(&dyn_buf) < 0)
-        return AVERROR(ENOMEM);
-
-    /* check if the strings are ASCII-only and use UTF16 only if
-     * they're not */
-    if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
-        (!str2 || string_is_ascii(str2)))
-        enc = ID3v2_ENCODING_ISO8859;
-
-    avio_w8(dyn_buf, enc);
-    if (enc == ID3v2_ENCODING_UTF16BOM) {
-        avio_wl16(dyn_buf, 0xFEFF);      /* BOM */
-        put = avio_put_str16le;
-    } else
-        put = avio_put_str;
-
-    put(dyn_buf, str1);
-    if (str2)
-        put(dyn_buf, str2);
-    len = avio_close_dyn_buf(dyn_buf, &pb);
-
-    avio_wb32(s->pb, tag);
-    id3v2_put_size(s, len);
-    avio_wb16(s->pb, 0);
-    avio_write(s->pb, pb, len);
-
-    av_freep(&pb);
-    return len + ID3v2_HEADER_SIZE;
-}
-
 typedef struct MP3Context {
     const AVClass *class;
     int id3v2_version;
@@ -191,21 +133,6 @@ static const AVClass mp3_muxer_class = {
     .version        = LIBAVUTIL_VERSION_INT,
 };
 
-static int id3v2_check_write_tag(AVFormatContext *s, AVDictionaryEntry *t, const char table[][4],
-                                 enum ID3v2Encoding enc)
-{
-    uint32_t tag;
-    int i;
-
-    if (t->key[0] != 'T' || strlen(t->key) != 4)
-        return -1;
-    tag = AV_RB32(t->key);
-    for (i = 0; *table[i]; i++)
-        if (tag == AV_RB32(table[i]))
-            return id3v2_put_ttag(s, t->value, NULL, tag, enc);
-    return -1;
-}
-
 /* insert a dummy frame containing number of frames */
 static void mp3_write_xing(AVFormatContext *s)
 {
@@ -259,46 +186,11 @@ static void mp3_write_xing(AVFormatContext *s)
 static int mp3_write_header(struct AVFormatContext *s)
 {
     MP3Context  *mp3 = s->priv_data;
-    AVDictionaryEntry *t = NULL;
-    int totlen = 0, enc = mp3->id3v2_version == 3 ? ID3v2_ENCODING_UTF16BOM :
-                                                    ID3v2_ENCODING_UTF8;
-    int64_t size_pos, cur_pos;
-
-    avio_wb32(s->pb, MKBETAG('I', 'D', '3', mp3->id3v2_version));
-    avio_w8(s->pb, 0);
-    avio_w8(s->pb, 0); /* flags */
-
-    /* reserve space for size */
-    size_pos = avio_tell(s->pb);
-    avio_wb32(s->pb, 0);
-
-    ff_metadata_conv(&s->metadata, ff_id3v2_34_metadata_conv, NULL);
-    if (mp3->id3v2_version == 4)
-        ff_metadata_conv(&s->metadata, ff_id3v2_4_metadata_conv, NULL);
-
-    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
-        int ret;
-
-        if ((ret = id3v2_check_write_tag(s, t, ff_id3v2_tags, enc)) > 0) {
-            totlen += ret;
-            continue;
-        }
-        if ((ret = id3v2_check_write_tag(s, t, mp3->id3v2_version == 3 ?
-                                               ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
-            totlen += ret;
-            continue;
-        }
-
-        /* unknown tag, write as TXXX frame */
-        if ((ret = id3v2_put_ttag(s, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
-            return ret;
-        totlen += ret;
-    }
+    int ret;
 
-    cur_pos = avio_tell(s->pb);
-    avio_seek(s->pb, size_pos, SEEK_SET);
-    id3v2_put_size(s, totlen);
-    avio_seek(s->pb, cur_pos, SEEK_SET);
+    ret = ff_id3v2_write(s, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
+    if (ret < 0)
+        return ret;
 
     if (s->pb->seekable)
         mp3_write_xing(s);