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Process compressed id3v2 tags.

ID3v2.4 allows for zlib compressed tags, but libavformat skips them.
Implement code to inflate compressed tags.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Adrian Drzewiecki 2011-12-24 11:06:22 -08:00 committed by Michael Niedermayer
parent 3701d547ac
commit 7e09fe15d5

View File

@ -26,6 +26,12 @@
* http://id3.org/Developer_Information
*/
#include "config.h"
#if CONFIG_ZLIB
#include <zlib.h>
#endif
#include "id3v2.h"
#include "id3v1.h"
#include "libavutil/avstring.h"
@ -432,6 +438,8 @@ static void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t
unsigned char *buffer = NULL;
int buffer_size = 0;
const ID3v2EMFunc *extra_func;
unsigned char *compressed_buffer = NULL;
int compressed_buffer_size = 0;
switch (version) {
case 2:
@ -476,6 +484,9 @@ static void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t
while (len >= taghdrlen) {
unsigned int tflags = 0;
int tunsync = 0;
int tcomp = 0;
int tencr = 0;
int dlen;
if (isv34) {
avio_read(s->pb, tag, 4);
@ -509,24 +520,65 @@ static void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t
if (tflags & ID3v2_FLAG_DATALEN) {
if (tlen < 4)
break;
avio_rb32(s->pb);
dlen = avio_rb32(s->pb);
tlen -= 4;
}
} else
dlen = tlen;
if (tflags & (ID3v2_FLAG_ENCRYPTION | ID3v2_FLAG_COMPRESSION)) {
av_log(s, AV_LOG_WARNING, "Skipping encrypted/compressed ID3v2 frame %s.\n", tag);
tcomp = tflags & ID3v2_FLAG_COMPRESSION;
tencr = tflags & ID3v2_FLAG_ENCRYPTION;
/* skip encrypted tags and, if no zlib, compressed tags */
if (tencr || (!CONFIG_ZLIB && tcomp)) {
const char *type;
if (!tcomp)
type = "encrypted";
else if (!tencr)
type = "compressed";
else
type = "encrypted and compressed";
av_log(s, AV_LOG_WARNING, "Skipping %s ID3v2 frame %s.\n", type, tag);
avio_skip(s->pb, tlen);
/* check for text tag or supported special meta tag */
} else if (tag[0] == 'T' || (extra_meta && (extra_func = get_extra_meta_func(tag, isv34)))) {
if (unsync || tunsync) {
if (unsync || tunsync || tcomp) {
int i, j;
av_fast_malloc(&buffer, &buffer_size, tlen);
av_fast_malloc(&buffer, &buffer_size, dlen);
if (!buffer) {
av_log(s, AV_LOG_ERROR, "Failed to alloc %d bytes\n", tlen);
av_log(s, AV_LOG_ERROR, "Failed to alloc %d bytes\n", dlen);
goto seek;
}
for (i = 0, j = 0; i < tlen; i++, j++) {
buffer[j] = avio_r8(s->pb);
#if CONFIG_ZLIB
if (tcomp) {
int n, err;
av_log(s, AV_LOG_DEBUG, "Compresssed frame %s tlen=%d dlen=%d\n", tag, tlen, dlen);
av_fast_malloc(&compressed_buffer, &compressed_buffer_size, tlen);
if (!compressed_buffer) {
av_log(s, AV_LOG_ERROR, "Failed to alloc %d bytes\n", tlen);
goto seek;
}
n = avio_read(s->pb, compressed_buffer, tlen);
if (n < 0) {
av_log(s, AV_LOG_ERROR, "Failed to read compressed tag\n");
goto seek;
}
err = uncompress(buffer, &dlen, compressed_buffer, n);
if (err != Z_OK) {
av_log(s, AV_LOG_ERROR, "Failed to uncompress tag: %d\n", err);
goto seek;
}
}
#endif
for (i = 0, j = 0; i < dlen; i++, j++) {
if (!tcomp)
buffer[j] = avio_r8(s->pb);
if (j > 0 && !buffer[j] && buffer[j - 1] == 0xff) {
/* Unsynchronised byte, skip it */
j--;
@ -564,6 +616,7 @@ seek:
av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
avio_seek(s->pb, end, SEEK_SET);
av_free(buffer);
av_free(compressed_buffer);
return;
}