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Bug #388

IPTV Imagenio Spain - > epoll_wait = 1

Added by Phill Lavender over 13 years ago. Updated about 13 years ago.

Status:
Fixed
Priority:
Normal
Assignee:
-
Category:
IPTV
Target version:
2.13
Start date:
2011-02-27
Due date:
% Done:

0%

Estimated time:
Found in version:
Affected Versions:

Description

Looks like there's something stopping TVheadend processing streams (UDP, RTP) from Imagenio in Spain. - lastest GITs. - Trying my best to isolate it, but not really a coder so appreciate the assistance.

Attached Wireshark log shows TVheaded is bound to the multicast group (239.0.0.74:8208) and receiving UDP. (User data appears to start the TS header at byte 47, which I think is a little odd given the RTP v2 header is 16 bytes? , haven't got much further with that yet though.)

based on the above monitoring the Epoll_wait() function in iptv_input.c each packet returns a int value of 1 (?) so ends up in a continuous loop.
---

while(1) {
    nfds = epoll_wait(iptv_epollfd, &ev, 1, 1);
    if(nfds == -1) {
      tvhlog(LOG_ERR, "IPTV", "epoll() error - %s, sleeping 1 second",
         strerror(errno));
      sleep(1);
      continue;
    }
 //  tvhlog(LOG_INFO, "IPTV", "\"%d\" epoll() events", nfds); // bad logging...
if(nfds < 1) 
      continue;

Files

capture1 (2.16 MB) capture1 Phill Lavender, 2011-02-27 20:35

History

#1

Updated by Phill Lavender over 13 years ago

Ok. I can't read C ! It doesn't get stuck in a loop that's what the continue means re-loop.

Real issue here is setting the size of the hlen for the RTP packet, 0x90 is the first byte of a RTP v2 packet.

int hlen = (tsb0 & 0xf) * 4 + 12;

So tsb0 is 0x90 'bitwise and' with 0xf = 0x00. * 4 +12 = 12 so the header is set for 12 bytes, however the header on the attached logs is 28 bytes. Hence it's not getting parsed into the TS packets correctly.

Phill

#2

Updated by Andreas Smas over 13 years ago

Hi

Thanks for a good bug report (which capture and everything)

This is hopefully committed in commit:98975cf4

#3

Updated by Andreas Smas over 13 years ago

  • Status changed from New to Fixed
  • Target version set to 2.13
#4

Updated by Phill Lavender over 13 years ago

Hi Andreas,

Checked your fix, your missing 4 bytes from the example RTP header I provided in the Wireshark log.

---fix ---

if(tsb[0] & 0x10) {
    // Extension (X bit) == true
if(r < hlen + 4)
      continue; // Packet size < hlen + extension header
// Skip over extension header (last 2 bytes of header is length)
    hlen += ((tsb[hlen + 2] << 8) | tsb[hlen + 3]) * 4;
tvhlog(LOG_DEBUG, "IPTV", "\"%d\":RTP Header Length", hlen); // test logging

---- Proof---
[DEBUG]:IPTV: "24":RTP Header Length
[DEBUG]:IPTV: "24":RTP Header Length
[DEBUG]:IPTV: "24":RTP Header Length
etc

I added (+4) to the end of the last line and it works fine. i.e;

hlen += ((tsb[hlen + 2] << 8) | tsb[hlen + 3]) * 4 + 4 // Don't think this is really the right way to do it though.

Phill

#5

Updated by Phill Lavender about 13 years ago

pull request #40 -
Added Extension Header Length (4 bytes) which isn't included in the EHL field in the Header
Once accepted hopefully closed

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