ffmpeg: make track names visible regarless of locale

Apple will not show a track name if it doesn't match the current locale
or it's language is not "und".  This patch results in the language being
set to "und".

writes 3gpp track names for all language variations in metadata.
when the language is not specified, uses "und" as default.

HandBrake doesn't actually allow multiple track name languages, but one
of the side effects of this patch is to use "und" when the track name
language is unspecified. Before this patch, language specific variants
of metadata were ignored and "eng" was always set as the language.

1 files changed, 77 insertions, 0 deletions

diff --git a/contrib/ffmpeg/A08-movenc-write-3gpp-track-names-tags-for-all-available.patch b/contrib/ffmpeg/A08-movenc-write-3gpp-track-names-tags-for-all-available.patch
new file mode 100644
index 000000000..88604aa3e
--- /dev/null
+++ b/contrib/ffmpeg/A08-movenc-write-3gpp-track-names-tags-for-all-available.patch
@@ -0,0 +1,77 @@
+From defbe24539ad6e2564db84641a84543256f8609f Mon Sep 17 00:00:00 2001
+From: John Stebbins <[email protected]>
+Date: Tue, 6 Aug 2019 11:45:11 -0600
+Subject: [PATCH] movenc: write 3gpp track names tags for all available
+ languages
+
+Metadata keys can have a language suffix.  Iterate through all language
+variations of the metadata key.
+---
+ libavformat/movenc.c | 28 ++++++++++++++++++++++++++--
+ 1 file changed, 26 insertions(+), 2 deletions(-)
+
+diff --git a/libavformat/movenc.c b/libavformat/movenc.c
+index b1b6ef0e4e..3d9800d386 100644
+--- a/libavformat/movenc.c
++++ b/libavformat/movenc.c
+@@ -26,6 +26,7 @@
+ 
+ #include "movenc.h"
+ #include "avformat.h"
++#include "avlanguage.h"
+ #include "avio_internal.h"
+ #include "riff.h"
+ #include "avio.h"
+@@ -3089,15 +3090,25 @@ static int mov_write_3gp_udta_tag(AVIOContext *pb, AVDictionary *metadata,
+ {
+     int64_t pos = avio_tell(pb);
+     AVDictionaryEntry *t = av_dict_get(metadata, str, NULL, 0);
++
+     if (!t || !utf8len(t->value))
+         return 0;
++
+     avio_wb32(pb, 0);   /* size */
+     ffio_wfourcc(pb, tag); /* type */
+     avio_wb32(pb, 0);   /* version + flags */
+     if (!strcmp(tag, "yrrc"))
+         avio_wb16(pb, atoi(t->value));
+     else {
+-        avio_wb16(pb, language_code("eng")); /* language */
++        int lang = 0, len;
++        len = strlen(t->key);
++        if (t->key[len - 4] == '-') {
++            lang = ff_mov_iso639_to_lang(&t->key[len - 3], 1);
++        }
++        if (!lang)
++            lang = ff_mov_iso639_to_lang("und", 1);
++
++        avio_wb16(pb, lang); /* language */
+         avio_write(pb, t->value, strlen(t->value) + 1); /* UTF8 string value */
+         if (!strcmp(tag, "albm") &&
+             (t = av_dict_get(metadata, "track", NULL, 0)))
+@@ -3135,8 +3146,21 @@ static int mov_write_track_udta_tag(AVIOContext *pb, MOVMuxContext *mov,
+         return ret;
+ 
+     if (mov->mode & (MODE_MP4|MODE_MOV)) {
++        AVDictionaryEntry *t = NULL;
++        int und = 0;
++
+         mov_write_track_metadata(pb_buf, st, "name", "title");
+-        mov_write_3gp_udta_tag(pb_buf, st->metadata, "titl", "title");
++        while ((t = av_dict_get(st->metadata, "title-", t, AV_DICT_IGNORE_SUFFIX))) {
++            int len = strlen(t->key);
++            if (len == 10 &&
++                ff_convert_lang_to(&t->key[len - 3], AV_LANG_ISO639_2_BIBL)) {
++                mov_write_3gp_udta_tag(pb_buf, st->metadata, "titl", t->key);
++                if (!strcmp("und", &t->key[len - 3]))
++                    und = 1;
++            }
++        }
++        if (!und)
++            mov_write_3gp_udta_tag(pb_buf, st->metadata, "titl", "title");
+     }
+ 
+     if ((size = avio_close_dyn_buf(pb_buf, &buf)) > 0) {
+-- 
+2.21.0
+