Commit 8a4cc0a2 authored by Richard Shaffer's avatar Richard Shaffer Committed by wm4

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: 's avatarwm4 <nfxjfg@googlemail.com>
parent f0320afa
......@@ -33,6 +33,7 @@
#endif
#include "libavutil/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
#include "avio_internal.h"
......@@ -1224,3 +1225,50 @@ end:
av_freep(&chapters);
return ret;
}
int ff_id3v2_parse_priv_dict(AVDictionary **metadata, ID3v2ExtraMeta **extra_meta)
{
ID3v2ExtraMeta *cur;
int dict_flags = AV_DICT_DONT_OVERWRITE | AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL;
for (cur = *extra_meta; cur; cur = cur->next) {
if (!strcmp(cur->tag, "PRIV")) {
ID3v2ExtraMetaPRIV *priv = cur->data;
AVBPrint bprint;
char *escaped, *key;
int i, ret;
if ((key = av_asprintf(ID3v2_PRIV_METADATA_PREFIX "%s", priv->owner)) == NULL) {
return AVERROR(ENOMEM);
}
av_bprint_init(&bprint, priv->datasize + 1, AV_BPRINT_SIZE_UNLIMITED);
for (i = 0; i < priv->datasize; i++) {
if (priv->data[i] < 32 || priv->data[i] > 126 || priv->data[i] == '\\') {
av_bprintf(&bprint, "\\x%02x", priv->data[i]);
} else {
av_bprint_chars(&bprint, priv->data[i], 1);
}
}
if ((ret = av_bprint_finalize(&bprint, &escaped)) < 0) {
av_free(key);
return ret;
}
if ((ret = av_dict_set(metadata, key, escaped, dict_flags)) < 0) {
av_free(key);
av_free(escaped);
return ret;
}
}
}
return 0;
}
int ff_id3v2_parse_priv(AVFormatContext *s, ID3v2ExtraMeta **extra_meta)
{
return ff_id3v2_parse_priv_dict(&s->metadata, extra_meta);
}
......@@ -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[];
......
......@@ -96,6 +96,59 @@ static int id3v2_put_ttag(ID3v2EncContext *id3, AVIOContext *avioc, const char *
return len + ID3v2_HEADER_SIZE;
}
/**
* Write a priv frame with owner and data. 'key' is the owner prepended with
* ID3v2_PRIV_METADATA_PREFIX. 'data' is provided as a string. Any \xXX
* (where 'X' is a valid hex digit) will be unescaped to the byte value.
*/
static int id3v2_put_priv(ID3v2EncContext *id3, AVIOContext *avioc, const char *key, const char *data)
{
int len;
uint8_t *pb;
AVIOContext *dyn_buf;
if (!av_strstart(key, ID3v2_PRIV_METADATA_PREFIX, &key)) {
return 0;
}
if (avio_open_dyn_buf(&dyn_buf) < 0)
return AVERROR(ENOMEM);
// owner + null byte.
avio_write(dyn_buf, key, strlen(key) + 1);
while (*data) {
if (av_strstart(data, "\\x", &data)) {
if (data[0] && data[1] && av_isxdigit(data[0]) && av_isxdigit(data[1])) {
char digits[] = {data[0], data[1], 0};
avio_w8(dyn_buf, strtol(digits, NULL, 16));
data += 2;
} else {
ffio_free_dyn_buf(&dyn_buf);
av_log(avioc, AV_LOG_ERROR, "Invalid escape '\\x%.2s' in metadata tag '"
ID3v2_PRIV_METADATA_PREFIX "%s'.\n", data, key);
return AVERROR(EINVAL);
}
} else {
avio_write(dyn_buf, data++, 1);
}
}
len = avio_close_dyn_buf(dyn_buf, &pb);
avio_wb32(avioc, MKBETAG('P', 'R', 'I', 'V'));
if (id3->version == 3)
avio_wb32(avioc, len);
else
id3v2_put_size(avioc, len);
avio_wb16(avioc, 0);
avio_write(avioc, pb, len);
av_free(pb);
return len + ID3v2_HEADER_SIZE;
}
static int id3v2_check_write_tag(ID3v2EncContext *id3, AVIOContext *pb, AVDictionaryEntry *t,
const char table[][4], enum ID3v2Encoding enc)
{
......@@ -186,6 +239,13 @@ static int write_metadata(AVIOContext *pb, AVDictionary **metadata,
continue;
}
if ((ret = id3v2_put_priv(id3, pb, t->key, t->value)) > 0) {
id3->len += ret;
continue;
} else if (ret < 0) {
return ret;
}
/* unknown tag, write as TXXX frame */
if ((ret = id3v2_put_ttag(id3, pb, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
return ret;
......
......@@ -637,6 +637,8 @@ int avformat_open_input(AVFormatContext **ps, const char *filename,
goto fail;
if ((ret = ff_id3v2_parse_chapters(s, &id3v2_extra_meta)) < 0)
goto fail;
if ((ret = ff_id3v2_parse_priv(s, &id3v2_extra_meta)) < 0)
goto fail;
} else
av_log(s, AV_LOG_DEBUG, "demuxer does not support additional id3 data, skipping\n");
}
......
......@@ -33,7 +33,7 @@
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 58
#define LIBAVFORMAT_VERSION_MINOR 5
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_MICRO 101
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
......
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