wav: parse 'bext' metadata

Signed-off-by: Anton Khirnov <anton@khirnov.net>

doc/general.texi

@@ -66,7 +66,7 @@ library:
     @tab Used in Z and Z95 games.
 @item Brute Force & Ignorance   @tab   @tab X
     @tab Used in the game Flash Traffic: City of Angels.
-@item BWF                       @tab X @tab
+@item BWF                       @tab X @tab X
 @item Interplay C93             @tab   @tab X
     @tab Used in the game Cyberia from Interplay.
 @item Delphine Software International CIN @tab   @tab X

libavformat/wav.c

@@ -23,6 +23,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/avassert.h"
+#include "libavutil/dict.h"
 #include "libavutil/log.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
@@ -32,6 +34,7 @@
 #include "riff.h"
 #include "avio.h"
 #include "avio_internal.h"
+#include "metadata.h"
 
 typedef struct {
     const AVClass *class;
@@ -284,6 +287,97 @@ 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;
+
+    av_assert0(length <= sizeof(temp));
+    if ((ret = avio_read(s->pb, temp, length)) < 0)
+        return ret;
+
+    temp[length] = 0;
+
+    if (strlen(temp))
+        return av_dict_set(&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), "%"PRIu64, time_reference);
+    if ((ret = av_dict_set(&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%016"PRIX64"%016"PRIX64"%016"PRIX64"%016"PRIX64,
+                         umid_parts[0], umid_parts[1], umid_parts[2], umid_parts[3]);
+            } else {
+                /* extended UMID */
+                snprintf(temp, sizeof(temp), "0x%016"PRIX64"%016"PRIX64"%016"PRIX64"%016"PRIX64
+                                             "0x%016"PRIX64"%016"PRIX64"%016"PRIX64"%016"PRIX64,
+                         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_dict_set(&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_dict_set(&s->metadata, "coding_history", coding_history,
+                               AV_METADATA_DONT_STRDUP_VAL)) < 0)
+            return ret;
+    }
+
+    return 0;
+}
+
+static const AVMetadataConv wav_metadata_conv[] = {
+    {"description",      "comment"      },
+    {"originator",       "encoded_by"   },
+    {"origination_date", "date"         },
+    {"origination_time", "creation_time"},
+    {0},
+};
+
 /* wav input */
 static int wav_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
@@ -369,6 +463,10 @@ 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;
         }
 
         /* seek to next tag unless we know that we'll run into EOF */
@@ -389,6 +487,9 @@ break_loop:
         sample_count = (data_size<<3) / (st->codec->channels * (uint64_t)av_get_bits_per_sample(st->codec->codec_id));
     if (sample_count)
         st->duration = sample_count;
+
+    ff_metadata_conv_ctx(s, NULL, wav_metadata_conv);
+
     return 0;
 }