PD#118065: cts: add mov support parsing QuickTime Metadata Keys

merge it from newer ffmpeg version
	commit 9ea812692c38c58a343cec5f66e8949655906edc
	Author: Tinglin Liu <tinglin@google.com>
	Date:   Thu Oct 22 15:04:46 2015 -0700

    		mov: Add support parsing QuickTime Metadata Keys.

Change-Id: I96c03fc4c6d7525db84f5767d1325e44c3f686d7

2 files changed, 95 insertions, 5 deletions

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 828e500..73ae25a 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -151,6 +151,10 @@ typedef struct MOVContext {
     int64_t duration;     ///< duration of the longest track
     int found_moov;       ///< 'moov' atom has been found
     int found_mdat;       ///< 'mdat' atom has been found
+    int found_hdlr_mdta;  ///< 'hdlr' atom with type 'mdta' has been found
+    int trak_index;       ///< Index of the current 'trak'
+    char **meta_keys;
+    unsigned meta_keys_count;
     DVDemuxContext *dv_demux;
     AVFormatContext *dv_fctx;
     int isom;             ///< 1 if file is ISO Media (mp4/3gp)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 7d026df..ff0d0be 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -551,6 +551,16 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
                     av_log(c->fc, AV_LOG_ERROR, "Error parsing cover art.\n");
                     return ret;
                 }
+            } else if (!key && c->found_hdlr_mdta && c->meta_keys) {
+                uint32_t index = AV_RB32(&atom.type);
+                if (index < c->meta_keys_count) {
+                    key = c->meta_keys[index];
+                } else {
+                    av_log(c->fc, AV_LOG_WARNING,
+                           "The index of 'data' is out of range: %d >= %d.\n",
+                           index, c->meta_keys_count);
+                }
+
             }
         } else return 0;
     } else if (atom.size > 4 && key && !c->itunes_metadata) {
@@ -587,6 +597,17 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             mov_read_mac_string(c, pb, str_size, str, sizeof(str));
         } else if (data_type == 13 || data_type == 14){
             mov_extract_cover_pic(c->fc, pb, data_type, cover_size, str);
+        } else if (data_type == 23 && str_size >= 4) {  // BE float32
+            // Allocates enough space if data_type is a float32 number
+            int str_size_alloc = 512 + 1;
+            float val = av_int2float(avio_rb32(pb));
+            if (snprintf(str, str_size_alloc, "%f", val) >= str_size_alloc) {
+                av_log(c->fc, AV_LOG_ERROR,
+                       "Failed to store the float32 number (%f) in string.\n", val);
+                av_free(str);
+                return AVERROR_INVALIDDATA;
+            }
+
         } else {
             avio_read(pb, str, str_size);
             str[str_size] = 0;
@@ -759,11 +780,6 @@ static int mov_read_hdlr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     int title_size;
     char *title_str;
 
-    if (c->fc->nb_streams < 1) // meta before first trak
-        return 0;
-
-    st = c->fc->streams[c->fc->nb_streams-1];
-
     avio_r8(pb); /* version */
     avio_rb24(pb); /* flags */
 
@@ -774,6 +790,15 @@ static int mov_read_hdlr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     av_dlog(c->fc, "ctype= %.4s (0x%08x)\n", (char*)&ctype, ctype);
     av_dlog(c->fc, "stype= %.4s\n", (char*)&type);
 
+    if (c->trak_index < 0) {  // meta not inside a trak
+        if (type == MKTAG('m','d','t','a')) {
+            c->found_hdlr_mdta = 1;
+        }
+        return 0;
+    }
+
+    st = c->fc->streams[c->fc->nb_streams-1];
+
     if     (type == MKTAG('v','i','d','e'))
         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     else if (type == MKTAG('s','o','u','n'))
@@ -2538,10 +2563,13 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     st->priv_data = sc;
     st->codec->codec_type = AVMEDIA_TYPE_DATA;
     sc->ffindex = st->index;
+    c->trak_index = st->index;
 
     if ((ret = mov_read_default(c, pb, atom)) < 0)
         return ret;
 
+    c->trak_index = -1;
+
     /* sanity checks */
     if (sc->chunk_count && (!sc->stts_count || !sc->stsc_count ||
                             (!sc->sample_size && !sc->sample_count))) {
@@ -2630,6 +2658,48 @@ static int mov_read_ilst(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     return ret;
 }
 
+static int mov_read_keys(MOVContext *c, AVIOContext *pb, MOVAtom atom)
+{
+    uint32_t count;
+    uint32_t i;
+
+    if (atom.size < 8)
+        return 0;
+
+    avio_skip(pb, 4);
+    count = avio_rb32(pb);
+    if (count > UINT_MAX / sizeof(*c->meta_keys)) {
+        av_log(c->fc, AV_LOG_ERROR,
+               "The 'keys' atom with the invalid key count: %d\n", count);
+        return AVERROR_INVALIDDATA;
+    }
+
+    c->meta_keys_count = count + 1;
+    c->meta_keys = av_mallocz(c->meta_keys_count * sizeof(*c->meta_keys));
+    if (!c->meta_keys)
+        return AVERROR(ENOMEM);
+
+    for (i = 1; i <= count; ++i) {
+        uint32_t key_size = avio_rb32(pb);
+        uint32_t type = avio_rl32(pb);
+        if (key_size < 8) {
+            av_log(c->fc, AV_LOG_ERROR,
+                   "The key# %d in meta has invalid size: %d\n", i, key_size);
+            return AVERROR_INVALIDDATA;
+        }
+        key_size -= 8;
+        if (type != MKTAG('m','d','t','a')) {
+            avio_skip(pb, key_size);
+        }
+        c->meta_keys[i] = av_mallocz(key_size + 1);
+        if (!c->meta_keys[i])
+            return AVERROR(ENOMEM);
+        avio_read(pb, c->meta_keys[i], key_size);
+    }
+
+    return 0;
+}
+
 static int mov_read_meta(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 {
     while (atom.size > 8) {
@@ -3279,6 +3349,14 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
                        atom.type == MKTAG('i','l','s','t')))
             parse = mov_read_udta_string;
 
+        // Supports parsing the QuickTime Metadata Keys.
+        // https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/Metadata/Metadata.html
+        if (!parse && c->found_hdlr_mdta &&
+            atom.type == MKTAG('m','e','t','a') &&
+            a.type == MKTAG('k','e','y','s')) {
+            parse = mov_read_keys;
+        }
+
         if (!parse) { /* skip leaf atoms data */
             avio_skip(pb, a.size);
         } else {
@@ -3541,6 +3619,13 @@ static int mov_read_close(AVFormatContext *s)
         av_freep(&mov->dv_demux);
     }
 
+    if (mov->meta_keys) {
+        for (i = 1; i < mov->meta_keys_count; i++) {
+            av_freep(&mov->meta_keys[i]);
+        }
+        av_freep(&mov->meta_keys);
+    }
+
     av_freep(&mov->trex_data);
     av_freep(&mov->bitrates);
 
@@ -3589,6 +3674,7 @@ static int mov_read_header(AVFormatContext *s)
     MOVAtom atom = { AV_RL32("root") };
 
     mov->fc = s;
+    mov->trak_index = -1;
     /* .mov and .mp4 aren't streamable anyway (only progressive download if moov is before mdat) */
     if (pb->seekable)
         atom.size = avio_size(pb);