Backed out changeset 0b900c9e0940 (bug 1038046) for Wasabi bustage. a=backout

netwerk/protocol/rtsp/rtsp/AH263Assembler.cpp

@@ -99,70 +99,18 @@ ARTPAssembler::AssemblyStatus AH263Assembler::addPacket(
         return MALFORMED_PACKET;
     }
 
-    // RFC 4629, Sec. 5.1 General H.263+ Payload Header.
-    // The H.263+ payload header is structured as follows:
-    //  0                   1
-    //  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
-    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-    // |   RR    |P|V|   PLEN    |PEBIT|
-    // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-    //
-    // RR: 5 bits
-    //     Reserved bits. It SHALL be zero and MUST be ignored by receivers.
-    // P: 1 bit
-    //     Indicates the picture start or a picture segment (GOB/Slice) start or
-    //     a video sequence end (EOS or EOSBS). Two bytes of zero bits then have
-    //     to be prefixed to the payload of such a packet to compose a complete
-    //     picture/GOB/slice/EOS/EOSBS start code. This bit allows the omission
-    //     of the two first bytes of the start code, thus improving the
-    //     compression ratio.
-    // V: 1 bit
-    //     Indicates the presence of an 8-bit field containing information for
-    //     Video Redundancy Coding (VRC), which follows immediately after the
-    //     initial 16 bits of the payload header.
-    // PLEN: 6 bits
-    //     Length, in bytes, of the extra picture header. If no extra picture
-    //     header is attached, PLEN is 0. If PLEN>0, the extra picture header is
-    //     attached immediately following the rest of the payload header. Note
-    //     that the length reflects the omission of the first two bytes of the
-    //     picture start code (PSC).
-    // PEBIT: 3 bits
-    //     Indicates the number of bits that shall be ignored in the last byte
-    //     of the picture header. If PLEN is not zero, the ignored bits shall be
-    //     the least significant bits of the byte. If PLEN is zero, then PEBIT
-    //     shall also be zero.
-
     unsigned payloadHeader = U16_AT(buffer->data());
+    CHECK_EQ(payloadHeader >> 11, 0u);  // RR=0
     unsigned P = (payloadHeader >> 10) & 1;
-    unsigned V = (payloadHeader >> 9) & 1;
-    unsigned PLEN = (payloadHeader >> 3) & 0x3f;
-    unsigned PEBIT = payloadHeader & 7;
-
-    // V = 0
-    // We do not support VRC header extension for now, so just discard it if
-    // present.
-    if (V != 0u) {
-        queue->erase(queue->begin());
-        ++mNextExpectedSeqNo;
-        ALOGW("Packet discarded due to VRC (V != 0)");
-        return MALFORMED_PACKET;
-    }
-
-    // If PLEN is zero, then PEBIT shall also be zero.
-    if (PLEN == 0u && PEBIT != 0u) {
-        queue->erase(queue->begin());
-        ++mNextExpectedSeqNo;
-        ALOGW("Packet discarded (PEBIT != 0)");
-        return MALFORMED_PACKET;
-    }
-
-    size_t skip = PLEN + (P ? 0: 2);
-
-    buffer->setRange(buffer->offset() + skip, buffer->size() - skip);
+    CHECK_EQ((payloadHeader >> 9) & 1, 0u);  // V=0
+    CHECK_EQ((payloadHeader >> 3) & 0x3f, 0u);  // PLEN=0
+    CHECK_EQ(payloadHeader & 7, 0u);  // PEBIT=0
 
     if (P) {
         buffer->data()[0] = 0x00;
         buffer->data()[1] = 0x00;
+    } else {
+        buffer->setRange(buffer->offset() + 2, buffer->size() - 2);
     }
 
     mPackets.push_back(buffer);