NZ DTT Testing
The Auckland DTT (Digital Terrestrial TV) Tests fired up over the weekend. The Waiatarua transmission is currently showing 14 active services, although some have duplicate video
streams
Linux users can either use the tool w_scan to perform a full UHF scan for potential DVB streams, or the following to perform a quick channel scan with dvbscan -
# Waiatarua, Auckland NZ # # Channel allocation details for NZ can be found at # http://www.rsm.govt.nz/cms/policy-and-planning/current-projects/broadcasting/digital-television-2007-frequency-plan # # T freq bw fec_hi fec_lo mod transmission-mode guard-interval hierarchy # Multiplex DA T 538000000 8MHz 3/4 3/4 QAM64 8k 1/16 NONE # Multiplex DB T 570000000 8MHz 3/4 3/4 QAM64 8k 1/16 NONE # Multiplex DC T 666000000 8MHz 3/4 3/4 QAM64 8k 1/16 NONE
The output of a channel scan sadly isn’t enough for mplayer to tune in correctly. First up the standard builds of both dvbscan and w_scan don’t consider H.264 to be a valid video stream.
In the case of the dvb-utils package the following patch adds support for H.264 streams
--- linuxtv-dvb-apps-1.1.1.orig/util/scan/scan.c
+++ linuxtv-dvb-apps-1.1.1/util/scan/scan.c
@@ -755,6 +757,7 @@
switch (buf[0]) {
case 0x01:
case 0x02:
+ case 0x1b: /* H.264 video stream */
moreverbose(" VIDEO : PID 0x%04xn",elementary_pid);
if (s->video_pid == 0)
s->video_pid = elementary_pid;
Now it gets a tad annoying as we still don’t have a channels.conf file we can use with mplayer as it treats the H.264 video streams as MPEG2. Checking back through the mailing lists it appears we need to add additional info to the vPID entry in the channels.conf file such as the PMT of the channel.
After some minor tweaking I’ve ended up with the following usable channels.conf file.
TVNZ 6:538000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512+256+1:580:1202 TVNZ 7:538000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513+257+1:581:1203 TVONE:538000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514+258+1:582:1200 TV2:538000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:+258+1582:1201 TVNZ SPORTS EXTRA:538000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:580:1204 C4:570000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512+356+1:580:1301 TV3:570000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514+358+1:582:1300 Maori TV:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:550+200+1:600:1400 Parliament:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:551+201+1:601:1401 C4a:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:552+202+1:602:1402 Regional 1SD:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:553+203+1:603:1403 TV3a:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:556+206+1:606:1406 Concert-FM:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:611:2000 National-Radio:666000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:606:2001
With this file I can now try to play the DTT streams via mplayer as follows -
mplayer dvb://TVONE
Most of the streams are either 1080i or 576i. Sadly the MPlayer and FFMPEG support for interlaced PAFF H.264 encoding is still broken so I can only do limited analysis of the streams at this stage.
TVNZ Mux has 5 channels but only 3 different video streams on 538000. Two of the streams are 1080i and one stream is 576i. One of the 1080i HD streams is running at a reasonable 6 Mbit, whilst the SD 576i stream is around 2 Mbit.
MediaWorks Mux has two channels on 570000, but the video streams are duplicates of streams from the TVNZ Mux with the same bitrate levels.
Kordia Mux on 666000 has some bad data in the channel table as the radio channels haven’t been mapped correctly. I was able to correct the aPID values in my channels.conf file manually.
On the Kordia Mux we appear to have two live channels, Paliament TV and Maori TV. These are both running SD 576i H.264 with 3 Mbit video.
The duplicate version of C4 also looks to be a live feed of C4 in 576i flagged to 16:9. The additional TV3 feed was running a HD 720p feed at 5Mbit, but was just a black video signal when I looked earlier this evening.
Of the two radio stations I could only get an audio stream from off one, the other refused to play.
Overall off to a good start. Surprised at the lack of AC3 audio streams on the HD channels. Also I’d expect to see the TVNZ channels move over to 720p when they switch from test loops to live feeds.
I’ll be passing some additional test streams onto the FFMPEG and MythTV teams to assist with the implementation of H.264 PAFF support.