Go to the documentation of this file.00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
00014
00015
00016
00017
00018
00019
00020
00021
00022
00023 #include "libavutil/intreadwrite.h"
00024 #include "libavutil/dict.h"
00025 #include "avformat.h"
00026 #include "apetag.h"
00027
00028 #define APE_TAG_VERSION 2000
00029 #define APE_TAG_FOOTER_BYTES 32
00030 #define APE_TAG_FLAG_CONTAINS_HEADER (1 << 31)
00031 #define APE_TAG_FLAG_IS_HEADER (1 << 29)
00032
00033 static int ape_tag_read_field(AVFormatContext *s)
00034 {
00035 AVIOContext *pb = s->pb;
00036 uint8_t key[1024], *value;
00037 uint32_t size;
00038 int i, c;
00039
00040 size = avio_rl32(pb);
00041 avio_skip(pb, 4);
00042 for (i = 0; i < sizeof(key) - 1; i++) {
00043 c = avio_r8(pb);
00044 if (c < 0x20 || c > 0x7E)
00045 break;
00046 else
00047 key[i] = c;
00048 }
00049 key[i] = 0;
00050 if (c != 0) {
00051 av_log(s, AV_LOG_WARNING, "Invalid APE tag key '%s'.\n", key);
00052 return -1;
00053 }
00054 if (size > INT32_MAX - FF_INPUT_BUFFER_PADDING_SIZE) {
00055 av_log(s, AV_LOG_ERROR, "APE tag size too large.\n");
00056 return AVERROR_INVALIDDATA;
00057 }
00058 value = av_malloc(size+1);
00059 if (!value)
00060 return AVERROR(ENOMEM);
00061 avio_read(pb, value, size);
00062 value[size] = 0;
00063 av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
00064 return 0;
00065 }
00066
00067 void ff_ape_parse_tag(AVFormatContext *s)
00068 {
00069 AVIOContext *pb = s->pb;
00070 int64_t file_size = avio_size(pb);
00071 uint32_t val, fields, tag_bytes;
00072 uint8_t buf[8];
00073 int i;
00074
00075 if (file_size < APE_TAG_FOOTER_BYTES)
00076 return;
00077
00078 avio_seek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
00079
00080 avio_read(pb, buf, 8);
00081 if (strncmp(buf, "APETAGEX", 8)) {
00082 return;
00083 }
00084
00085 val = avio_rl32(pb);
00086 if (val > APE_TAG_VERSION) {
00087 av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
00088 return;
00089 }
00090
00091 tag_bytes = avio_rl32(pb);
00092 if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
00093 av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
00094 return;
00095 }
00096
00097 fields = avio_rl32(pb);
00098 if (fields > 65536) {
00099 av_log(s, AV_LOG_ERROR, "Too many tag fields (%d)\n", fields);
00100 return;
00101 }
00102
00103 val = avio_rl32(pb);
00104 if (val & APE_TAG_FLAG_IS_HEADER) {
00105 av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
00106 return;
00107 }
00108
00109 avio_seek(pb, file_size - tag_bytes, SEEK_SET);
00110
00111 for (i=0; i<fields; i++)
00112 if (ape_tag_read_field(s) < 0) break;
00113 }