avformat/flvdec: add several error messages to error conditions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/flvdec.c

@@ -405,8 +405,10 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
         num_val = avio_r8(ioc);
         break;
     case AMF_DATA_TYPE_STRING:
-        if (amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
+        if (amf_get_string(ioc, str_val, sizeof(str_val)) < 0) {
+            av_log(s, AV_LOG_ERROR, "AMF_DATA_TYPE_STRING parsing failed\n");
             return -1;
+        }
         break;
     case AMF_DATA_TYPE_OBJECT:
         if ((vstream || astream) && key &&
@@ -421,8 +423,10 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
             if (amf_parse_object(s, astream, vstream, str_val, max_pos,
                                  depth + 1) < 0)
                 return -1;     // if we couldn't skip, bomb out.
-        if (avio_r8(ioc) != AMF_END_OF_OBJECT)
+        if (avio_r8(ioc) != AMF_END_OF_OBJECT) {
+            av_log(s, AV_LOG_ERROR, "Missing AMF_END_OF_OBJECT in AMF_DATA_TYPE_OBJECT\n");
             return -1;
+        }
         break;
     case AMF_DATA_TYPE_NULL:
     case AMF_DATA_TYPE_UNDEFINED:
@@ -438,7 +442,10 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
                                  depth + 1) < 0)
                 return -1;
         if (avio_r8(ioc) != AMF_END_OF_OBJECT)
+        if (avio_r8(ioc) != AMF_END_OF_OBJECT) {
+            av_log(s, AV_LOG_ERROR, "Missing AMF_END_OF_OBJECT in AMF_DATA_TYPE_MIXEDARRAY\n");
             return -1;
+        }
         break;
     case AMF_DATA_TYPE_ARRAY:
     {
@@ -455,6 +462,7 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream,
         avio_skip(ioc, 8 + 2);  // timestamp (double) and UTC offset (int16)
         break;
     default:                    // unsupported type, we couldn't skip
+        av_log(s, AV_LOG_ERROR, "unsupported amf type %d\n", amf_type);
         return -1;
     }