avformat: add option to parse/store ID3 PRIV tags in metadata.

Enables getting access to ID3 PRIV tags from the command-line or metadata API
when demuxing. The PRIV owner is stored as the metadata key prepended with
"id3v2_priv.", and the data is stored as the metadata value. As PRIV tags may
contain arbitrary data, non-printable characters, including NULL bytes, are
escaped as \xXX.

Similarly, any metadata tags that begin with "id3v2_priv." are inserted as ID3
PRIV tags into the output (assuming the format supports ID3). \xXX sequences in
the value are un-escaped to their byte value.

Signed-off-by: wm4 <nfxjfg@googlemail.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/libavformat/id3v2.h b/libavformat/id3v2.h
index 5e64ead096..9de0bee374 100644
--- a/libavformat/id3v2.h
+++ b/libavformat/id3v2.h
@@ -39,6 +39,8 @@
 #define ID3v2_FLAG_ENCRYPTION  0x0004
 #define ID3v2_FLAG_COMPRESSION 0x0008
 
+#define ID3v2_PRIV_METADATA_PREFIX "id3v2_priv."
+
 enum ID3v2Encoding {
     ID3v2_ENCODING_ISO8859  = 0,
     ID3v2_ENCODING_UTF16BOM = 1,
@@ -167,6 +169,19 @@ int ff_id3v2_parse_apic(AVFormatContext *s, ID3v2ExtraMeta **extra_meta);
  */
 int ff_id3v2_parse_chapters(AVFormatContext *s, ID3v2ExtraMeta **extra_meta);
 
+/**
+ * Parse PRIV tags into a dictionary. The PRIV owner is the metadata key. The
+ * PRIV data is the value, with non-printable characters escaped.
+ */
+int ff_id3v2_parse_priv_dict(AVDictionary **d, ID3v2ExtraMeta **extra_meta);
+
+/**
+ * Add metadata for all PRIV tags in the ID3v2 header. The PRIV owner is the
+ * metadata key. The PRIV data is the value, with non-printable characters
+ * escaped.
+ */
+int ff_id3v2_parse_priv(AVFormatContext *s, ID3v2ExtraMeta **extra_meta);
+
 extern const AVMetadataConv ff_id3v2_34_metadata_conv[];
 extern const AVMetadataConv ff_id3v2_4_metadata_conv[];