rmdec: correct DTS calculation in RealMedia container.

First, container stores only DTS and not PTS as it was believed.
Second, multiple frames in a packet store timestamp instead of position
after the frame length.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavformat/rmdec.c

@@ -568,7 +568,8 @@ skip:
 
 static int rm_assemble_video_frame(AVFormatContext *s, AVIOContext *pb,
                                    RMDemuxContext *rm, RMStream *vst,
-                                   AVPacket *pkt, int len, int *pseq)
+                                   AVPacket *pkt, int len, int *pseq,
+                                   int64_t *timestamp)
 {
     int hdr, seq, pic_num, len2, pos;
     int type;
@@ -588,8 +589,10 @@ static int rm_assemble_video_frame(AVFormatContext *s, AVIOContext *pb,
         return -1;
     rm->remaining_len = len;
     if(type&1){     // frame, not slice
-        if(type == 3)  // frame as a part of packet
+        if(type == 3){  // frame as a part of packet
             len= len2;
+            *timestamp = pos;
+        }
         if(rm->remaining_len < len)
             return -1;
         rm->remaining_len -= len;
@@ -697,7 +700,7 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
 
     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
         rm->current_stream= st->id;
-        if(rm_assemble_video_frame(s, pb, rm, ast, pkt, len, seq))
+        if(rm_assemble_video_frame(s, pb, rm, ast, pkt, len, seq, &timestamp))
             return -1; //got partial frame
     } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
         if ((st->codec->codec_id == CODEC_ID_RA_288) ||
@@ -772,7 +775,7 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
     }
 #endif
 
-    pkt->pts= timestamp;
+    pkt->pts = timestamp;
     if (flags & 2)
         pkt->flags |= AV_PKT_FLAG_KEY;
 

tests/ref/fate/rv30

@@ -1,16 +1,16 @@
 0, 0, 126720, 0xcefaec47
 0, 7500, 126720, 0xa416ece5
 0, 15000, 126720, 0xa416ece5
-0, 22500, 126720, 0xa416ece5
-0, 30000, 126720, 0xcc10f4b7
+0, 22500, 126720, 0x259af497
+0, 30000, 126720, 0x5e6ff4d7
 0, 37500, 126720, 0xeb6fb8d7
-0, 45000, 126720, 0xda71b917
-0, 52500, 126720, 0xbb1abbb7
-0, 60000, 126720, 0x273fbc37
-0, 67500, 126720, 0x16eebbd7
-0, 75000, 126720, 0x105eb927
-0, 82500, 126720, 0x7fa3ae27
-0, 90000, 126720, 0xd115a757
+0, 45000, 126720, 0xbb1abbb7
+0, 52500, 126720, 0x273fbc37
+0, 60000, 126720, 0x7fa3ae27
+0, 67500, 126720, 0x722e99f7
+0, 75000, 126720, 0x29d6a887
+0, 82500, 126720, 0xd115a757
+0, 90000, 126720, 0x6ddaef32
 0, 97500, 126720, 0x04e7897c
 0, 105000, 126720, 0x68cfda2b
 0, 112500, 126720, 0xe572dfc9
@@ -25,11 +25,11 @@
 0, 180000, 126720, 0x72f2a47d
 0, 187500, 126720, 0x4f639ebe
 0, 195000, 126720, 0x534a10cc
-0, 202500, 126720, 0xfdca11d3
+0, 202500, 126720, 0x5fd753d8
 0, 210000, 126720, 0x0c735615
 0, 217500, 126720, 0x0eaf0c1b
-0, 225000, 126720, 0xce5e6794
-0, 232500, 126720, 0x14cf7974
+0, 225000, 126720, 0x14cf7974
+0, 232500, 126720, 0x1c2a513d
 0, 240000, 126720, 0xbc513f2a
 0, 247500, 126720, 0xbc303fae
 0, 255000, 126720, 0xd9f67585