[vlc-devel] [PATCH] demux: mp4: Add support for GoPro HiLight tags as chapters, so they can appear in the progress bar

[Emeric Grange]

---
 modules/demux/mp4/libmp4.c | 41 +++++++++++++++++++++++++++++++++++++++++
 modules/demux/mp4/libmp4.h | 15 +++++++++++++++
 modules/demux/mp4/mp4.c    | 22 ++++++++++++++++++++++
 3 files changed, 78 insertions(+)

diff --git a/modules/demux/mp4/libmp4.c b/modules/demux/mp4/libmp4.c
index e902ac8..f7918da 100644
--- a/modules/demux/mp4/libmp4.c
+++ b/modules/demux/mp4/libmp4.c
@@ -3175,6 +3175,46 @@ static int MP4_ReadBox_chpl( stream_t *p_stream, MP4_Box_t *p_box )
     MP4_READBOX_EXIT( 1 );
 }
 
+/* GoPro HiLight tags support */
+static void MP4_FreeBox_hmmt( MP4_Box_t *p_box )
+{
+    MP4_Box_data_HMMT_t *p_hmmt = p_box->data.p_hmmt;
+    for( unsigned i = 0; i < p_hmmt->i_chapter; i++ )
+        free( p_hmmt->chapter[i].psz_name );
+}
+
+static int MP4_ReadBox_HMMT( stream_t *p_stream, MP4_Box_t *p_box )
+{
+    MP4_Box_data_HMMT_t *p_hmmt;
+    char tag_nb[4] = {0};
+
+    MP4_READBOX_ENTER( MP4_Box_data_HMMT_t, MP4_FreeBox_hmmt );
+
+    p_hmmt = p_box->data.p_hmmt;
+
+    MP4_GET4BYTES( p_hmmt->i_chapter );
+
+    for( uint32_t i = 0; i < p_hmmt->i_chapter; i++ )
+    {
+        uint64_t i_start;
+
+        p_hmmt->chapter[i].psz_name = malloc( 18 );
+        if( !p_hmmt->chapter[i].psz_name )
+            MP4_READBOX_EXIT( 0 );
+        strncpy(p_hmmt->chapter[i].psz_name, "HiLight tag #", 17);
+        snprintf(tag_nb, 3, "%d", i + 1);
+        strncat(p_hmmt->chapter[i].psz_name, tag_nb, 4);
+
+        MP4_GET4BYTES( i_start );
+        p_hmmt->chapter[i].i_start = i_start;
+    }
+
+    msg_Dbg( p_stream, "read box: \"HMMT\" %d HiLight tags",
+                       p_hmmt->i_chapter );
+
+    MP4_READBOX_EXIT( 1 );
+}
+
 static void MP4_FreeBox_tref_generic( MP4_Box_t *p_box )
 {
     FREENULL( p_box->data.p_tref_generic->i_track_ID );
@@ -3971,6 +4011,7 @@ static const struct
     { ATOM_name,    MP4_ReadBox_String,    ATOM_udta },
     { ATOM_vndr,    MP4_ReadBox_String,    ATOM_udta },
     { ATOM_SDLN,    MP4_ReadBox_String,    ATOM_udta },
+    { ATOM_HMMT,    MP4_ReadBox_HMMT,      ATOM_udta }, /* GoPro HiLights */
 
     /* udta, non meta */
     { ATOM_tsel,    MP4_ReadBox_tsel,    ATOM_udta },
diff --git a/modules/demux/mp4/libmp4.h b/modules/demux/mp4/libmp4.h
index 62a6b30..b2ca71e 100644
--- a/modules/demux/mp4/libmp4.h
+++ b/modules/demux/mp4/libmp4.h
@@ -314,6 +314,7 @@ typedef int64_t stime_t;
 #define ATOM_0xa9xyz VLC_FOURCC( 0xa9, 'x', 'y', 'z' )
 #define ATOM_aART VLC_FOURCC( 'a', 'A', 'R', 'T' )
 #define ATOM_chpl VLC_FOURCC( 'c', 'h', 'p', 'l' )
+#define ATOM_HMMT VLC_FOURCC( 'H', 'M', 'M', 'T' )
 #define ATOM_disk VLC_FOURCC( 'd', 'i', 's', 'k' )
 #define ATOM_WLOC VLC_FOURCC( 'W', 'L', 'O', 'C' )
 
@@ -1103,6 +1104,19 @@ typedef struct
 
 typedef struct
 {
+    uint8_t  i_version;
+    uint32_t i_flags;
+
+    uint32_t i_chapter;
+    struct
+    {
+        char    *psz_name;
+        int64_t  i_start;
+    } chapter[400];
+} MP4_Box_data_HMMT_t;
+
+typedef struct
+{
     uint8_t i_version;
     uint8_t i_profile;
     uint8_t i_profile_compatibility;
@@ -1490,6 +1504,7 @@ typedef union MP4_Box_data_s
 
     MP4_Box_data_pnot_t *p_pnot;
     MP4_Box_data_chpl_t *p_chpl;
+    MP4_Box_data_HMMT_t *p_hmmt;
     MP4_Box_data_tref_generic_t *p_tref_generic;
 
     MP4_Box_data_tfrf_t *p_tfrf;
diff --git a/modules/demux/mp4/mp4.c b/modules/demux/mp4/mp4.c
index ff9fb3b..9bec173 100644
--- a/modules/demux/mp4/mp4.c
+++ b/modules/demux/mp4/mp4.c
@@ -1774,6 +1774,23 @@ static void LoadChapterGpac( demux_t  *p_demux, MP4_Box_t *p_chpl )
         TAB_APPEND( p_sys->p_title->i_seekpoint, p_sys->p_title->seekpoint, s );
     }
 }
+static void LoadChapterGoPro( demux_t  *p_demux, MP4_Box_t *p_chpl )
+{
+    demux_sys_t *p_sys = p_demux->p_sys;
+    int i;
+
+    p_sys->p_title = vlc_input_title_New();
+    for( i = 0; i < BOXDATA(p_chpl)->i_chapter; i++ )
+    {
+        seekpoint_t *s = vlc_seekpoint_New();
+
+        s->psz_name = strdup( BOXDATA(p_chpl)->chapter[i].psz_name );
+        EnsureUTF8( s->psz_name );
+        // HiLights are expressed in ms, convert to µs
+        s->i_time_offset = BOXDATA(p_chpl)->chapter[i].i_start * 1000;
+        TAB_APPEND( p_sys->p_title->i_seekpoint, p_sys->p_title->seekpoint, s );
+    }
+}
 static void LoadChapterApple( demux_t  *p_demux, mp4_track_t *tk )
 {
     demux_sys_t *p_sys = p_demux->p_sys;
@@ -1823,6 +1840,11 @@ static void LoadChapter( demux_t  *p_demux )
     {
         LoadChapterGpac( p_demux, p_chpl );
     }
+    else if( ( p_chpl = MP4_BoxGet( p_sys->p_root, "/moov/udta/HMMT" ) ) &&
+          BOXDATA(p_chpl) && BOXDATA(p_chpl)->i_chapter > 0 )
+    {
+        LoadChapterGoPro( p_demux, p_chpl );
+    }
     else if( p_sys->p_tref_chap )
     {
         MP4_Box_data_tref_generic_t *p_chap = p_sys->p_tref_chap->data.p_tref_generic;
-- 
2.6.2