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rtpdec: Identify incorrectly signalled H263

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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 <martin@martin.st>
This commit is contained in:
Martin Storsjö 2012-02-17 10:27:41 +02:00
parent b1af4e9c27
commit c7e8639c70
3 changed files with 32 additions and 10 deletions
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4
libavformat/rtpdec_formats.h
View File

@ -31,6 +31,10 @@
*/
int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p);
int ff_h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags);
extern RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler;
extern RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler;
extern RTPDynamicProtocolHandler ff_g726_16_dynamic_handler;

14
libavformat/rtpdec_h263.c
View File

@ -23,13 +23,9 @@
#include "rtpdec_formats.h"
#include "libavutil/intreadwrite.h"
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 ff_h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags)
{
uint8_t *ptr;
uint16_t header;
@ -96,12 +92,12 @@ RTPDynamicProtocolHandler ff_h263_1998_dynamic_handler = {
.enc_name = "H263-1998",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = CODEC_ID_H263,
.parse_packet = h263_handle_packet,
.parse_packet = ff_h263_handle_packet,
};
RTPDynamicProtocolHandler ff_h263_2000_dynamic_handler = {
.enc_name = "H263-2000",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = CODEC_ID_H263,
.parse_packet = h263_handle_packet,
.parse_packet = ff_h263_handle_packet,
};

24
libavformat/rtpdec_h263_rfc2190.c
View File

@ -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;