Identifying H.264 packetization mode

[nissarbm]

Hi All,

I captured the H.264 packets using ethereal. But I don't know, how to identify the packetization mode from the RTP packet.

Anybody have any idea on how to identify the packetization mode from the RTP packet.???

[jgg]

I was unable to properly decode RTP/H.264 packets with Wireshark and VLC some months ago. Maybe last Wireshark version can do it.

[nissarbm]

I am using Wireshark Version 1.0.2. It is properly able to decode the H.264 packet.

But I don't have any idea on how to identify the packetization mode from the packet captured.

Is there any header field that indicates the packetization mode used? Or Is there any other technique to get the packetization mode from the captured packet?

[jgg]

Could you please post the trace of a H.264 packet?

[nissarbm]

Here is the sample captured RTP packet.

Real-Time Transport Protocol
[Stream setup by SDP (frame 3)]
[Setup frame: 3]
[Setup Method: SDP]
10.. .... = Version: RFC 1889 Version (2)
..0. .... = Padding: False
...0 .... = Extension: False
.... 0000 = Contributing source identifiers count: 0
0... .... = Marker: False
Payload type: H264 (96)
Sequence number: 7226
[Extended sequence number: 72762]
Timestamp: 143722340
Synchronization Source identifier: 0x99f02d88 (2582654344)
H.264
NAL unit header or first byte of the payload
0... .... = F bit: No bit errors or other syntax violations
.01. .... = Nal_ref_idc (NRI): 1
...0 1000 = Type: NAL unit - Picture parameter set (8)
H264 bitstream
1... .... = pic_parameter_set_id: 0
.1.. .... = seq_parameter_set_id: 0
..0. .... = entropy_coding_mode_flag: 0
...0 .... = pic_order_present_flag: 0
.... 1... = num_slice_groups_minus1: 0
.... .1.. = num_ref_idx_l0_active_minus1: 0
.... ..1. = num_ref_idx_l1_active_minus1: 0
.... ...0 = weighted_pred_flag: 0
00.. .... = weighted_bipred_idc: 0
..00 0110 0... .... = pic_init_qp_minus26(se(v)): -6
.1.. .... = pic_init_qs_minus26: 0
..1. .... = chroma_qp_index_offset: 0
...1 .... = deblocking_filter_control_present_flag: 1
.... 0... = constrained_intra_pred_flag: 0
.... .0.. = redundant_pic_cnt_present_flag: 0
.... ..1. = rbsp_stop_bit: 1
.... ...0 = rbsp_trailing_bits: 0

[timeon]

I realize it is a very late answer. The packetization mode is communicated outside of the RTP stream, you would find it in the SDP in RTSP or SAP messages.