On Tue, 23 Jan 2018 09:39:53 -0800
rshaf...@tunein.com wrote:
> From: Richard Shaffer <rshaf...@tunein.com>
>
> 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.
> ---
> Whitespace changes re Moritz' comments on code format.
>
> libavformat/id3v2.c | 48 ++++++++++++++++++++++++++++++++++++++++
> libavformat/id3v2.h | 15 +++++++++++++
> libavformat/id3v2enc.c | 60
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> libavformat/utils.c | 2 ++
> 4 files changed, 125 insertions(+)
>
> diff --git a/libavformat/id3v2.c b/libavformat/id3v2.c
> index 6c216ba7a2..b80178d67a 100644
> --- a/libavformat/id3v2.c
> +++ b/libavformat/id3v2.c
> @@ -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);
> +}
> 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[];
>
> diff --git a/libavformat/id3v2enc.c b/libavformat/id3v2enc.c
> index 14de76ac06..ffe358f019 100644
> --- a/libavformat/id3v2enc.c
> +++ b/libavformat/id3v2enc.c
> @@ -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;
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index 3d733417e1..c15b8cc818 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -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");
> }
Pushed, with a libavformat microbump added.
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