h264: Parse registered data SEI message and AFD value

Partially based on code by Marton Balint and Kieran Kunhya.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/h264.c

@@ -822,6 +822,16 @@ static void decode_postinit(H264Context *h, int setup_finished)
                                h->sei_hflip, h->sei_vflip);
     }
 
+    if (h->sei_reguserdata_afd_present) {
+        AVFrameSideData *sd = av_frame_new_side_data(cur->f, AV_FRAME_DATA_AFD,
+                                                     sizeof(uint8_t));
+        if (!sd)
+            return;
+
+        *sd->data = h->active_format_description;
+        h->sei_reguserdata_afd_present = 0;
+    }
+
     // FIXME do something with unavailable reference frames
 
     /* Sort B-frames into display order */

libavcodec/h264.h

@@ -129,6 +129,7 @@ enum {
 typedef enum {
     SEI_TYPE_BUFFERING_PERIOD       = 0,   ///< buffering period (H.264, D.1.1)
     SEI_TYPE_PIC_TIMING             = 1,   ///< picture timing
+    SEI_TYPE_USER_DATA_REGISTERED   = 4,   ///< registered user data as specified by Rec. ITU-T T.35
     SEI_TYPE_USER_DATA_UNREGISTERED = 5,   ///< unregistered user data
     SEI_TYPE_RECOVERY_POINT         = 6,   ///< recovery point (frame # to decoder sync)
     SEI_TYPE_FRAME_PACKING          = 45,  ///< frame packing arrangement
@@ -674,6 +675,12 @@ typedef struct H264Context {
     int sei_anticlockwise_rotation;
     int sei_hflip, sei_vflip;
 
+    /**
+     * User data registered by Rec. ITU-T T.35 SEI
+     */
+    int sei_reguserdata_afd_present;
+    uint8_t active_format_description;
+
     /**
      * Bit set of clock types for fields/frames in picture timing SEI message.
      * For each found ct_type, appropriate bit is set (e.g., bit 1 for

libavcodec/h264_sei.c

@@ -42,6 +42,7 @@ void ff_h264_reset_sei(H264Context *h)
     h->sei_buffering_period_present =  0;
     h->sei_frame_packing_present    =  0;
     h->sei_display_orientation_present = 0;
+    h->sei_reguserdata_afd_present  =  0;
 }
 
 static int decode_picture_timing(H264Context *h)
@@ -102,6 +103,51 @@ static int decode_picture_timing(H264Context *h)
     return 0;
 }
 
+static int decode_registered_user_data(H264Context *h, int size)
+{
+    uint32_t country_code;
+    uint32_t user_identifier;
+    int flag;
+
+    if (size < 7)
+        return AVERROR_INVALIDDATA;
+    size -= 7;
+
+    country_code = get_bits(&h->gb, 8); // itu_t_t35_country_code
+    if (country_code == 0xFF) {
+        skip_bits(&h->gb, 8);           // itu_t_t35_country_code_extension_byte
+        size--;
+    }
+
+    /* itu_t_t35_payload_byte follows */
+    skip_bits(&h->gb, 8);              // terminal provider code
+    skip_bits(&h->gb, 8);              // terminal provider oriented code
+    user_identifier = get_bits_long(&h->gb, 32);
+
+    switch (user_identifier) {
+        case MKBETAG('D', 'T', 'G', '1'):       // afd_data
+            if (size-- < 1)
+                return AVERROR_INVALIDDATA;
+            skip_bits(&h->gb, 1);               // 0
+            flag = get_bits(&h->gb, 1);         // active_format_flag
+            skip_bits(&h->gb, 6);               // reserved
+
+            if (flag) {
+                if (size-- < 1)
+                    return AVERROR_INVALIDDATA;
+                skip_bits(&h->gb, 4);           // reserved
+                h->active_format_description   = get_bits(&h->gb, 4);
+                h->sei_reguserdata_afd_present = 1;
+            }
+            break;
+        default:
+            skip_bits(&h->gb, size * 8);
+            break;
+    }
+
+    return 0;
+}
+
 static int decode_unregistered_user_data(H264Context *h, int size)
 {
     uint8_t user_data[16 + 256];
@@ -247,6 +293,9 @@ int ff_h264_decode_sei(H264Context *h)
         case SEI_TYPE_PIC_TIMING: // Picture timing SEI
             ret = decode_picture_timing(h);
             break;
+        case SEI_TYPE_USER_DATA_REGISTERED:
+            ret = decode_registered_user_data(h, size);
+            break;
         case SEI_TYPE_USER_DATA_UNREGISTERED:
             ret = decode_unregistered_user_data(h, size);
             break;

libavcodec/version.h

@@ -30,7 +30,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 56
 #define LIBAVCODEC_VERSION_MINOR 29
-#define LIBAVCODEC_VERSION_MICRO  0
+#define LIBAVCODEC_VERSION_MICRO  1
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \