Parse 'bext' metadata in the wav demuxer

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/wav.c

@@ -204,6 +204,86 @@ static int wav_parse_fmt_tag(AVFormatContext *s, int64_t size, AVStream **st)
     return 0;
 }
 
+static inline int wav_parse_bext_string(AVFormatContext *s, const char *key, int length)
+{
+    char temp[257];
+    int ret;
+
+    if ((ret = avio_read(s->pb, temp, length)) < 0)
+        return ret;
+
+    temp[length] = 0;
+
+    if (strlen(temp))
+        return av_metadata_set2(&s->metadata, key, temp, 0);
+
+    return 0;
+}
+
+static int wav_parse_bext_tag(AVFormatContext *s, int64_t size)
+{
+    char temp[131], *coding_history;
+    int ret, x;
+    uint64_t time_reference;
+    int64_t umid_parts[8], umid_mask = 0;
+
+    if ((ret = wav_parse_bext_string(s, "description", 256)) < 0 ||
+        (ret = wav_parse_bext_string(s, "originator", 32)) < 0 ||
+        (ret = wav_parse_bext_string(s, "originator_reference", 32)) < 0 ||
+        (ret = wav_parse_bext_string(s, "origination_date", 10)) < 0 ||
+        (ret = wav_parse_bext_string(s, "origination_time", 8)) < 0)
+        return ret;
+
+    time_reference = avio_rl64(s->pb);
+    snprintf(temp, sizeof(temp), "%lu", time_reference);
+    if ((ret = av_metadata_set2(&s->metadata, "time_reference", temp, 0)) < 0)
+        return ret;
+
+    /* check if version is >= 1, in which case an UMID may be present */
+    if (avio_rl16(s->pb) >= 1) {
+        for (x = 0; x < 8; x++)
+            umid_mask |= umid_parts[x] = avio_rb64(s->pb);
+
+        if (umid_mask) {
+            /* the string formatting below is per SMPTE 330M-2004 Annex C */
+            if (umid_parts[4] == 0 && umid_parts[5] == 0 && umid_parts[6] == 0 && umid_parts[7] == 0) {
+                /* basic UMID */
+                snprintf(temp, sizeof(temp), "0x%016lX%016lX%016lX%016lX",
+                         umid_parts[0], umid_parts[1], umid_parts[2], umid_parts[3]);
+            } else {
+                /* extended UMID */
+                snprintf(temp, sizeof(temp), "0x%016lX%016lX%016lX%016lX%016lX%016lX%016lX%016lX",
+                         umid_parts[0], umid_parts[1], umid_parts[2], umid_parts[3],
+                         umid_parts[4], umid_parts[5], umid_parts[6], umid_parts[7]);
+            }
+
+            if ((ret = av_metadata_set2(&s->metadata, "umid", temp, 0)) < 0)
+                return ret;
+        }
+
+        avio_skip(s->pb, 190);
+    } else
+        avio_skip(s->pb, 254);
+
+    if (size > 602) {
+        /* CodingHistory present */
+        size -= 602;
+
+        if (!(coding_history = av_malloc(size+1)))
+            return AVERROR(ENOMEM);
+
+        if ((ret = avio_read(s->pb, coding_history, size)) < 0)
+            return ret;
+
+        coding_history[size] = 0;
+        if ((ret = av_metadata_set2(&s->metadata, "coding_history", coding_history,
+                                    AV_METADATA_DONT_STRDUP_VAL)) < 0)
+            return ret;
+    }
+
+    return 0;
+}
+
 /* wav input */
 static int wav_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
@@ -295,6 +375,10 @@ static int wav_read_header(AVFormatContext *s,
             if(!sample_count)
                 sample_count = avio_rl32(pb);
             break;
+        case MKTAG('b','e','x','t'):
+            if ((ret = wav_parse_bext_tag(s, size)) < 0)
+                return ret;
+            break;
         }
         avio_seek(pb, next_tag_ofs, SEEK_SET);
     }