Hi Mr Finlayson
Sorry just found out that you've replied question, I went through live555 mail
archives trying to find some answer.
? There is no bug in the LIVE555 code. There is perhaps a bug in the custom
code that the server uses to feed NAL units from the camera to the server.
Correct, it was only my assumption, the more I learn from mailing list, it is
intended to send frames in multiple packets, you already mentioned the
advantage of this from your older email.
? What is the value of the "numTruncatedBytes" parameter to this call? If
it's >0, then this means that the supplied buffer size (the "maxSize" parameter
to the call to "getNextFrame()" was too small, and needs to be increased.
This one already answered, I didn't get any error since my buffer is well above
the maxSize therefore numTruncatedBytes is always 0.
Let me rephrase my problem from my findings, for older camera I get the data
from getNextFrame() as follows
Nal Remark
32 VPS
33 SPS
34 PPS
19 I-Frame (full size)
1 P-Frame (full size)
...
1 P-Frame (full size)
These I & P frames can be fed to the decoder and I can get the picture without
problem.
For latest HEVC stream camera, the data will look like this
Nal Remark
32 VPS
33 SPS
34 PPS
39 Prefix
19 I-Frame (1/3 size)
19 I-Frame (1/3 size)
19 I-Frame (1/3 size)
39 Prefix
1 P-Frame (1/3 size)
1 P-Frame (1/3 size)
1 P-Frame (1/3 size)
....
39 Prefix
1 P-Frame (1/3 size)
1 P-Frame (1/3 size)
1 P-Frame (1/3 size)
That's where I tried to merge the fragmented frames before sending it to the
decoder.
I have tried to store the frame when I get Nal prefix (39) as follows on
afterGetFrame function
If (firstFU){
memcpy(temp_rtp_data, rtp_data, frameSize);
temp_buffer_size = frameSize;
firstFU = false;
}
else{
size_t data_pos = 6; /// I have experiment this with many
different values following hevc rfc document, still no avail
memcpy(temp_rtp_data + temp_buffer_size, rtp_data + data_pos,
frameSize - data_pos);
temp_buffer_size += frameSize - data_pos;
firstFU = false;
}
If I find another nal equal to 39, I send the data to the decoder, still I can
only see 1/3 frame being decoded.
I have tried to find answer anywhere (including SO), but couldn't get any,
there's also unanswered question regarding merging Fragmented Unit.
I am very new to video streaming world, the original code belongs to my client,
I'm grateful to have a chance to learn about it.
Also pardon for my lack of netiquette from my last email, I was mindlessly
replying to the email using outlook.
Best regards,
Firdaus
_______________________________________________
live-devel mailing list
live-devel@lists.live555.com
http://lists.live555.com/mailman/listinfo/live-devel
