From b84f3a40034d28828c4ca639d012479a7eaace28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Wed, 18 May 2016 13:54:11 +0300
Subject: [PATCH] movenc: Write 'loci' geotag metadata for 3gp and mp4
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Martin Storsjö <martin@martin.st>
---
 libavformat/movenc.c | 53 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 8f014d22d5..aadfa06a5a 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -2040,6 +2040,57 @@ static int mov_write_string_metadata(AVFormatContext *s, AVIOContext *pb,
     return mov_write_string_tag(pb, name, t->value, lang, long_style);
 }
 
+/* 3GPP TS 26.244 */
+static int mov_write_loci_tag(AVFormatContext *s, AVIOContext *pb)
+{
+    int lang;
+    int64_t pos = avio_tell(pb);
+    double latitude, longitude, altitude;
+    int32_t latitude_fix, longitude_fix, altitude_fix;
+    AVDictionaryEntry *t = get_metadata_lang(s, "location", &lang);
+    const char *ptr, *place = "";
+    char *end;
+    const char *astronomical_body = "earth";
+    if (!t)
+        return 0;
+
+    ptr = t->value;
+    longitude = strtod(ptr, &end);
+    if (end == ptr) {
+        av_log(s, AV_LOG_WARNING, "malformed location metadata\n");
+        return 0;
+    }
+    ptr = end;
+    latitude = strtod(ptr, &end);
+    if (end == ptr) {
+        av_log(s, AV_LOG_WARNING, "malformed location metadata\n");
+        return 0;
+    }
+    ptr = end;
+    altitude = strtod(ptr, &end);
+    /* If no altitude was present, the default 0 should be fine */
+    if (*end == '/')
+        place = end + 1;
+
+    latitude_fix  = (int32_t) ((1 << 16) * latitude);
+    longitude_fix = (int32_t) ((1 << 16) * longitude);
+    altitude_fix  = (int32_t) ((1 << 16) * altitude);
+
+    avio_wb32(pb, 0);         /* size */
+    ffio_wfourcc(pb, "loci"); /* type */
+    avio_wb32(pb, 0);         /* version + flags */
+    avio_wb16(pb, lang);
+    avio_write(pb, place, strlen(place) + 1);
+    avio_w8(pb, 0);           /* role of place (0 == shooting location, 1 == real location, 2 == fictional location) */
+    avio_wb32(pb, latitude_fix);
+    avio_wb32(pb, longitude_fix);
+    avio_wb32(pb, altitude_fix);
+    avio_write(pb, astronomical_body, strlen(astronomical_body) + 1);
+    avio_w8(pb, 0);           /* additional notes, null terminated string */
+
+    return update_size(pb, pos);
+}
+
 /* iTunes track number */
 static int mov_write_trkn_tag(AVIOContext *pb, MOVMuxContext *mov,
                               AVFormatContext *s)
@@ -2194,6 +2245,7 @@ static int mov_write_udta_tag(AVIOContext *pb, MOVMuxContext *mov,
         mov_write_3gp_udta_tag(pb_buf, s, "albm", "album");
         mov_write_3gp_udta_tag(pb_buf, s, "cprt", "copyright");
         mov_write_3gp_udta_tag(pb_buf, s, "yrrc", "date");
+        mov_write_loci_tag(s, pb_buf);
     } else if (mov->mode == MODE_MOV) { // the title field breaks gtkpod with mp4 and my suspicion is that stuff is not valid in mp4
         mov_write_string_metadata(s, pb_buf, "\251ART", "artist",      0);
         mov_write_string_metadata(s, pb_buf, "\251nam", "title",       0);
@@ -2211,6 +2263,7 @@ static int mov_write_udta_tag(AVIOContext *pb, MOVMuxContext *mov,
     } else {
         /* iTunes meta data */
         mov_write_meta_tag(pb_buf, mov, s);
+        mov_write_loci_tag(s, pb_buf);
     }
 
     if (s->nb_chapters && !(mov->flags & FF_MOV_FLAG_DISABLE_CHPL))