From c7e8639c70ec25be2c0afdcea61d992de5f1928e Mon Sep 17 00:00:00 2001 From: Martin Storsjö Date: Fri, 17 Feb 2012 10:27:41 +0200 Subject: rtpdec: Identify incorrectly signalled H263 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit H263 in RTP can be packetized in two formats (RFC 2190, RFC 2429/4629). The former normally uses the static payload type 34, while the latter normally uses dynamic payload types with the SDP format names H263-1998 or H263-2000. Look for packets that don't look like proper RFC 2190 packets and switch to depacketizing them according to the new format if they match some heuristic criteria. Signed-off-by: Martin Storsjö --- libavformat/rtpdec_h263_rfc2190.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'libavformat/rtpdec_h263_rfc2190.c') diff --git a/libavformat/rtpdec_h263_rfc2190.c b/libavformat/rtpdec_h263_rfc2190.c index baec6a427c..a3a4825719 100644 --- a/libavformat/rtpdec_h263_rfc2190.c +++ b/libavformat/rtpdec_h263_rfc2190.c @@ -35,6 +35,7 @@ struct PayloadContext { uint8_t endbyte; int endbyte_bits; uint32_t timestamp; + int newformat; }; static PayloadContext *h263_new_context(void) @@ -58,9 +59,14 @@ static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, int flags) { - int f, p, i, sbit, ebit; /* Corresponding to header fields in the RFC */ + /* Corresponding to header fields in the RFC */ + int f, p, i, sbit, ebit, src, r; int header_size; + if (data->newformat) + return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, len, + flags); + if (data->buf && data->timestamp != *timestamp) { /* Dropping old buffered, unfinished data */ uint8_t *p; @@ -80,6 +86,7 @@ static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data, /* Mode A */ header_size = 4; i = buf[1] & 0x10; + r = ((buf[1] & 0x01) << 3) | ((buf[2] & 0xe0) >> 5); } else if (!p) { /* Mode B */ header_size = 8; @@ -89,6 +96,7 @@ static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data, len, header_size); return AVERROR_INVALIDDATA; } + r = buf[3] & 0x03; i = buf[4] & 0x80; } else { /* Mode C */ @@ -99,10 +107,24 @@ static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data, len, header_size); return AVERROR_INVALIDDATA; } + r = buf[3] & 0x03; i = buf[4] & 0x80; } sbit = (buf[0] >> 3) & 0x7; ebit = buf[0] & 0x7; + src = (buf[1] & 0xe0) >> 5; + if (!(buf[0] & 0xf8)) { /* Reserved bits in RFC 2429/4629 are zero */ + if ((src == 0 || src >= 6) && r) { + /* Invalid src for this format, and bits that should be zero + * according to RFC 2190 aren't zero. */ + av_log(ctx, AV_LOG_WARNING, + "Interpreting H263 RTP data as RFC 2429/4629 even though " + "signalled with a static payload type.\n"); + data->newformat = 1; + return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, + len, flags); + } + } buf += header_size; len -= header_size; -- cgit v1.2.3