rtpmp4gdepay: detect broken senders who send AAC with ADTS frames

Strip ADTS headers if we detect any, apparently some Sony cameras
send AAC with ADTS headers. We could also change the stream-format
in the output caps, but that would be unexpected to pipeline builders
and would not exactly be backwards compatible.

diff --git a/gst/rtp/gstrtpmp4gdepay.c b/gst/rtp/gstrtpmp4gdepay.c
index 1709010728cc56fd4ab7902c0c82f102c912d466..5d9d2cdf2d218067fed508f5a61005d9aa70c84a 100644 (file)
--- a/gst/rtp/gstrtpmp4gdepay.c
+++ b/gst/rtp/gstrtpmp4gdepay.c
@@ -233,11 +233,14 @@ gst_rtp_mp4g_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
     clock_rate = 90000;         /* default */
   depayload->clock_rate = clock_rate;
 
+  rtpmp4gdepay->check_adts = FALSE;
+
   if ((str = gst_structure_get_string (structure, "media"))) {
     if (strcmp (str, "audio") == 0) {
       srccaps = gst_caps_new_simple ("audio/mpeg",
           "mpegversion", G_TYPE_INT, 4, "stream-format", G_TYPE_STRING, "raw",
           NULL);
+      rtpmp4gdepay->check_adts = TRUE;
     } else if (strcmp (str, "video") == 0) {
       srccaps = gst_caps_new_simple ("video/mpeg",
           "mpegversion", G_TYPE_INT, 4,
@@ -664,11 +667,30 @@ gst_rtp_mp4g_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)
         gst_adapter_push (rtpmp4gdepay->adapter, outbuf);
 
         if (M) {
+          guint32 v = 0;
           guint avail;
 
           /* packet is complete, flush */
           avail = gst_adapter_available (rtpmp4gdepay->adapter);
 
+          /* Some broken senders send ADTS headers (e.g. some Sony cameras).
+           * Try to detect those and skip them (still needs config set), but
+           * don't check every frame, only the first (unless we detect ADTS) */
+          if (rtpmp4gdepay->check_adts && avail >= 7) {
+            if (gst_adapter_masked_scan_uint32_peek (rtpmp4gdepay->adapter,
+                    0xfffe0000, 0xfff00000, 0, 4, &v) == 0) {
+              guint adts_hdr_len = (((v >> 16) & 0x1) == 0) ? 9 : 7;
+              if (avail > adts_hdr_len) {
+                GST_WARNING_OBJECT (rtpmp4gdepay, "Detected ADTS header of "
+                    "%u bytes, skipping", adts_hdr_len);
+                gst_adapter_flush (rtpmp4gdepay->adapter, adts_hdr_len);
+                avail -= adts_hdr_len;
+              }
+            } else {
+              rtpmp4gdepay->check_adts = FALSE;
+            }
+          }
+
           outbuf = gst_adapter_take_buffer (rtpmp4gdepay->adapter, avail);
 
           /* copy some of the fields we calculated above on the buffer. We also

diff --git a/gst/rtp/gstrtpmp4gdepay.h b/gst/rtp/gstrtpmp4gdepay.h
index 5d5997af31155af5afe6e6c36290a8f858086b8c..d4d9330c16149d754556cb14b7a6c540d67f164f 100644 (file)
--- a/gst/rtp/gstrtpmp4gdepay.h
+++ b/gst/rtp/gstrtpmp4gdepay.h
@@ -67,6 +67,8 @@ struct _GstRtpMP4GDepay
   guint32 prev_rtptime;
   guint prev_AU_num;
 
+  gboolean check_adts; /* check for ADTS headers */
+
   GQueue *packets;
   
   GstAdapter *adapter;