RF ATSC &/or QAM HDTV Modulator devices, methods & technology - Page 6 - AVS Forum | Home Theater Discussions And Reviews

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post #151 of 173 Old 11-09-2014, 03:50 PM
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Quote:
Originally Posted by cubsking99 View Post
Are you transcoding the video or just stream copying it?
Transcoding but would prefer copying if possible and then packetize the output.

The open caster manual used ffmpeg to extract stream and then seemed to use x264 (patched) to packetize it. But doing so still took 30% of my CPUs. When I tried all 3 cams, the CPUs were at 100%. Note that this is a virtual machine but still, even on bare bone, I'm sure it'd be sucking a lot of CPU.

So, yeah, my goal is copy if possible and then chunk it up (es -> pes -> ts -> mux -> atsc).

Steph
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post #152 of 173 Old 11-10-2014, 08:17 AM
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Quote:
Originally Posted by stefvie2k View Post
Transcoding but would prefer copying if possible and then packetize the output.

The open caster manual used ffmpeg to extract stream and then seemed to use x264 (patched) to packetize it. But doing so still took 30% of my CPUs. When I tried all 3 cams, the CPUs were at 100%. Note that this is a virtual machine but still, even on bare bone, I'm sure it'd be sucking a lot of CPU.

So, yeah, my goal is copy if possible and then chunk it up (es -> pes -> ts -> mux -> atsc).

Steph
I don't think you need to re-encode to do it. Try this:

Code:
ffmpeg -re -i SOURCE_URL -c:v copy -c:a copy -f mpegts
udp://127.0.0.1:1234?pkt_size=188&buffer_size=65535
You can use the pkt_size directive on RTP or UDP streams coming from ffmpeg. For more info, see here:

https://www.ffmpeg.org/ffmpeg-protocols.html

Hope that helps!

Mark
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post #153 of 173 Old 11-10-2014, 08:09 PM
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Quote:
Originally Posted by cubsking99 View Post
I don't think you need to re-encode to do it. Try this:

Code:
ffmpeg -re -i SOURCE_URL -c:v copy -c:a copy -f mpegts
udp://127.0.0.1:1234?pkt_size=188&buffer_size=65535
You can use the pkt_size directive on RTP or UDP streams coming from ffmpeg. For more info, see here:

https://www.ffmpeg.org/ffmpeg-protocols.html

Hope that helps!

Mark
Thanks... but I managed to get it to work with no transcoding. Basically, I'm going from my IP CAM's H264/AVC Part 10 stream to mpeg transport stream. Then I extract the video PES out of the TS and re-mux it into my ATSC transport stream with all my other PIDs.

...
ffmpeg -re -rtsp_transport tcp -i "rtsp://admin:12345@cam1.local:554/Streaming/Channels/1" -map 0:0 -an -c:v copy -streamid 0:65 -bsf dump_extra -y input.ts &
ts2pes input.ts 65 > video.pes &
...

... PID 65 is my Video stream defined as H264/AVC (0x1b) so I'm now able to broadcast my IP CAM in 1080P in H264 to my TVs.

Again, once I'm all done with my testing, I'll upload all my scripts to GitHub.

Steph
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post #154 of 173 Old 11-22-2014, 05:57 AM
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So Trip, did you get your stuff working?

JamesMHC, can you check your private messages?
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post #155 of 173 Old 11-22-2014, 08:59 PM
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Yes, I've successfully piped LPB through the house via your software. I was tinkering with my dish again today and have a borderline signal on OETA which means I should be close to having a signal good enough to try sending that one out as well.

I look forward to future developments!

- Trip

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post #156 of 173 Old 11-24-2014, 05:05 PM
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Quote:
Originally Posted by stefvie2k View Post
my Video stream defined as H264/AVC (0x1b) so I'm now able to broadcast my IP CAM in 1080P in H264 to my TVs.
So if you're leaving it H264, are your TVs able to natively show that or do you have something else decoding the stream to display?

I'm looking forward to seeing your scripts and source when you can get them posted...
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post #157 of 173 Old 11-25-2014, 07:31 PM
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Quote:
Originally Posted by cubsking99 View Post
So if you're leaving it H264, are your TVs able to natively show that or do you have something else decoding the stream to display?

I'm looking forward to seeing your scripts and source when you can get them posted...
Yeah, my Samsung Smart TV (series 6 2013 model) is able to decode the h264 stream, my old Sharp and Samsung TV/Monitor aren't able to.

I'm a bit busy lately because my son is having an asthma flare-up... but hopefully I'll be able to post this up soon...

Here's the ffmpeg/x264 script that I used to generate the test pattern.

Code:
~/bin/ffmpeg -v 0 -re -f lavfi -i "smptehdbars=size=1920x1080:rate=$video_frame_rate" \
  -vf drawtext="fontsize=15:fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf:timecode='00\:00\:00\:00':rate=$video_frame_rate:text='TCR\:':fontsize=72:fontcolor='white':boxcolor=0x000000AA:box=1:x=940-text_w/2:y=650" -c:v rawvideo -an -f yuv4mpegpipe -y video.y4m &

~/bin/x264 --profile baseline --level 4.0 --nal-hrd cbr --vbv-bufsize 200 --bitrate 720 --keyint 12 --vbv-init 0 -o video.pes video.y4m &
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post #158 of 173 Old 12-05-2014, 09:54 PM
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Hi All,

I've push new version of my program along with the source code onto the GitHub site at https://github.com/stefvie2k/HDTV998Server

PS: If anyone have some spare HDTV998 cards to donate me, let me know. Looks like the eBay seller of the "Lot of 5 HDTV998 cards" took my $ and closed his eBay store (hopefully will get my $ back once the PayPal resolution completes).

Enjoy,

Steph

Last edited by stefvie2k; 12-05-2014 at 11:00 PM.
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post #159 of 173 Old 12-19-2014, 05:57 AM
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Anyone know when the patents run out for the technology to produce a reasonable cost 8VSB modulator?

.
.
Free, abundant OTA television separates this country from many others. ATSC1 has only been in force since 2009. The wireless industry has enough spectrum. Enough of 'planned obsolesce'.
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post #160 of 173 Old 12-19-2014, 03:54 PM
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Quote:
Originally Posted by videobruce View Post
Anyone know when the patents run out for the technology to produce a reasonable cost 8VSB modulator?
Some of them have already expired in 2009. But that's not the reason why there are no low-cost modulators. It's more a function of the hardware required to generate the 8VSB signal.

For an NTSC modulator, all you need are a few transistors. For an 8VSB modulator, you need a D/A converter that can do 10.76 Msamples/s, an IQ modulator, an RF oscillator that has low enough phase noise to not destroy the signal and other not so cheap components.

The lowest cost more or less "off the shelf" solution today is $300 with a HackRF SDR board.

https://greatscottgadgets.com/hackrf/

I'm using the bladeRF SDR, which is $420.

http://nuand.com/

Of course, you need a computer to make it go. However, once you've configured everything, you can send any modulation you like. ATSC, QAM, DVB-T, DVB-T2, DVB-S, DVB-S2 and even NTSC.

So if by "reasonable cost", you mean $20 (the price of an NTSC modulator), it's probably never going to happen.

Ron

HD MPEG-2 Test Patterns http://www.w6rz.net
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post #161 of 173 Old 12-20-2014, 06:48 AM
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Quote:
So if by "reasonable cost", you mean $20 (the price of an NTSC modulator), it's probably never going to happen.
No, I would consdier that 'free'.
More like around $200 (+ or -).

Using those two examples you mentioned, what would be a guess on the cost to complete the package w/o a PC so it would be a stand alone unit?

.
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Free, abundant OTA television separates this country from many others. ATSC1 has only been in force since 2009. The wireless industry has enough spectrum. Enough of 'planned obsolesce'.
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post #162 of 173 Old 12-20-2014, 07:35 AM
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Quote:
Originally Posted by videobruce View Post
No, I would consdier that 'free'.
More like around $200 (+ or -).

Using those two examples you mentioned, what would be a guess on the cost to complete the package w/o a PC so it would be a stand alone unit?
The two examples quoted are SDR (Software Defined Radios). They require a PC to do the maths required to generate the I/Q signals that are fed over USB to the SDR device - effectively the PC is doing a lot of the processing required to modulate the signal. You will need a reasonably powerful PC to drive them - though this could be a small ITX box rather than an ATX or uATX tower I guess? (Don't think the lower power ARM boxes would have the processing grunt required for ATSC and DVB modulation?)
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post #163 of 173 Old 12-20-2014, 01:30 PM
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On bladeRF, the Nuand folks have moved some of the 8VSB functionality into the on-board FPGA. Instead of sending the raw IQ samples to the card, the 3-bit 8VSB modulation levels are sent. In theory, the entire 8VSB modulator could be moved into the FPGA, but it hasn't been attempted yet.

It takes significantly less CPU, but I haven't experimented with any of the low cost computer modules to see exactly what would work. However, there are some pretty powerful modules available now that make the Raspberry Pi look like a toy. The popular one with the SDR crowd is the Odroid U3.

http://www.hardkernel.com/main/main.php

Assuming that module could deliver enough performance, it gets you in the less than $500 range.

Here are the ATSC flow graphs with the first one doing all the processing on the PC and the second one using the FPGA accelerator. The symbol mapper block in the FPGA flow just packs four 3-bit modulation levels into a 32-bit word that the osmocom sink understands. The WX GUI FFT Sink block in the PC-based flow is optional and just displays the generated ATSC waveform (see last picture).







Ron

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post #164 of 173 Old 11-03-2015, 09:24 AM
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Just an FYI, the HDTV998 card will still work under Win 10 x32.

*EDIT* After a bit more playing with it under Win 10, I found that ExecutePlay doesn't work. You have to use Seamless mode. Unfortunately, that means you can't use my code that lets you fast forward, rewind, or just play part of a file. I've got an update that includes seamless playback. It will still allow you to pause and resume, but no skipping around in a file :-(

Last edited by cubsking99; 01-09-2016 at 09:01 PM. Reason: Added more info
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post #165 of 173 Old 01-09-2016, 09:18 PM
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After years of messing with it, I've finally (FINALLY!!!!) figured out an FFMPEG command that will let me live stream. Here's what I'm using:
  • FFMPEG build 20151213
  • stefvie2k's HDTV998Server
  • AverMedia U3 (for HDMI capture)
  • Core i7 Dell PC with 4GB RAM

With my device, I have a couple of .BAT files setup for capture at different resolutions. For 720p:

Code:
ffmpeg -rtbufsize 2000M -f dshow -video_size 1280x720 -framerate 30 -i video="AVerMedia U3 Video Capture":audio="AVerMedia U3 Video Capture" -vcodec mpeg2video -s 1280x720 -b:v 18000k -minrate 18000k -maxrate 18000k -bufsize 1900k -r 30 -async 1 -acodec ac3 -ab 392k -ar 48000 -pix_fmt yuv420p -f mpegts -muxrate 19392k tcp://127.0.0.1:12345
For 1080p:

Code:
ffmpeg -rtbufsize 2000M -f dshow -video_size 1280x720 -framerate 30 -i video="AVerMedia U3 Video Capture":audio="AVerMedia U3 Video Capture" -vcodec mpeg2video -s 1920x1080 -b:v 18000k -minrate 18000k -maxrate 18000k -bufsize 1900k -r 30 -async 1 -acodec ac3 -ab 392k -ar 48000 -pix_fmt yuv420p -f mpegts -muxrate 19392k tcp://127.0.0.1:12345
You'll have to change the settings for your input device. You may also have to mess with the bitrate parameters to make things work for you, but this appears to be working great on my Win 7 install.

I've had most of that command together for a while, but tonight was when I found the -muxrate option for mpegts to change it to a CBR stream.

Hope that helps and can save someone the headache that I've had to go through to get it working...

Mark
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post #166 of 173 Old 01-20-2016, 09:47 PM
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Quote:
Originally Posted by cubsking99 View Post
After years of messing with it, I've finally (FINALLY!!!!) figured out an FFMPEG command that will let me live stream. Here's what I'm using:
  • FFMPEG build 20151213
  • stefvie2k's HDTV998Server
  • AverMedia U3 (for HDMI capture)
  • Core i7 Dell PC with 4GB RAM

With my device, I have a couple of .BAT files setup for capture at different resolutions. For 720p:

Code:
ffmpeg -rtbufsize 2000M -f dshow -video_size 1280x720 -framerate 30 -i video="AVerMedia U3 Video Capture":audio="AVerMedia U3 Video Capture" -vcodec mpeg2video -s 1280x720 -b:v 18000k -minrate 18000k -maxrate 18000k -bufsize 1900k -r 30 -async 1 -acodec ac3 -ab 392k -ar 48000 -pix_fmt yuv420p -f mpegts -muxrate 19392k tcp://127.0.0.1:12345
For 1080p:

Code:
ffmpeg -rtbufsize 2000M -f dshow -video_size 1280x720 -framerate 30 -i video="AVerMedia U3 Video Capture":audio="AVerMedia U3 Video Capture" -vcodec mpeg2video -s 1920x1080 -b:v 18000k -minrate 18000k -maxrate 18000k -bufsize 1900k -r 30 -async 1 -acodec ac3 -ab 392k -ar 48000 -pix_fmt yuv420p -f mpegts -muxrate 19392k tcp://127.0.0.1:12345
You'll have to change the settings for your input device. You may also have to mess with the bitrate parameters to make things work for you, but this appears to be working great on my Win 7 install.

I've had most of that command together for a while, but tonight was when I found the -muxrate option for mpegts to change it to a CBR stream.

Hope that helps and can save someone the headache that I've had to go through to get it working...

Mark
This is great stuff. What's the latency like with the card + ffmpeg and it finally showing up on a TV over ATSC?

Tom
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post #167 of 173 Old 01-21-2016, 07:27 PM
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Quote:
Originally Posted by tbdombrosky View Post
This is great stuff. What's the latency like with the card + ffmpeg and it finally showing up on a TV over ATSC?
It seems to be about 3 to 4 seconds between when I press the Guide button on my Dish remote and when it shows up on the screen. I'm pretty happy with that.

I've also tweaked my command line a little. I'm running it from a batch script. I noticed that the audio and video were getting a little out of sync, so I set it up to run as a scheduled task that fires off every hour and queues instances if one is still running. I'm also passing in a param to the .BAT file so I can change the resolution between 720p and 1080p. I'm passing ffmpeg the option to run for 3600 seconds (i.e. 1 hour), so it quits after that time, and the next instance starts up. There's a little glitch at the change over, but it's no worse than what I see regularly from the Dish or from streaming media...

The newest version is this:

Code:
ffmpeg -rtbufsize 2000M -f dshow -video_size %1 -framerate 30 -i video="AVerMedia U3 Video Capture":audio="AVerMedia U3 Video Capture" -vcodec mpeg2video -s %1 -b:v 18000k -minrate 18000k -maxrate 18000k -bufsize 1900k -async 1 -acodec ac3 -ab 392k -ar 48000 -pix_fmt yuv420p -t 3600 -f mpegts -muxrate 19392k tcp://127.0.0.1:12345
Glad I can help :-D

Mark
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post #168 of 173 Old 01-21-2016, 08:32 PM
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You may want to try -framerate 30000/1001 to fix your A/V sync issue.

Ron

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post #169 of 173 Old 01-22-2016, 06:57 AM
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Thread title edited. Figured this has become a catch-all reference thread for HD Modulation devices, methods and technology so this title might better reflect it, though suggestions are welcome. I have a lot of characters left

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post #170 of 173 Old 01-22-2016, 09:02 AM
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Quote:
Originally Posted by videobruce View Post
Anyone know when the patents run out for the technology to produce a reasonable cost 8VSB modulator?
Quote:
Originally Posted by dr1394 View Post
Some of them have already expired in 2009. But that's not the reason why there are no low-cost modulators. It's more a function of the hardware required to generate the 8VSB signal....

So if by "reasonable cost", you mean $20 (the price of an NTSC modulator), it's probably never going to happen....
Quote:
Originally Posted by videobruce View Post
No, I would consdier that 'free'.
More like around $200 (+ or -). ...
So then, just counting marginal unit production costs, if there is no licensing fee or royalty due on a basic stand-alone 8VSB modulator, then should the cost of an 8VSB modulator now approach that of a stand-alone QAM modulator? How much is ZeeVee selling those for? I haven't checked in a couple of years.
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post #171 of 173 Old Yesterday, 08:23 PM
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HD modulator - will this one work?

I'm in the US and I need to be able to modulate an HDMI signal to an HDTV. If I understand correctly, the signal needs to be encoded MPEG2/AC3 and then modulated ATSC in order for a US Television to be able to receive it. Are there any other parameters I need to look for. Here is a link to a modulator that I think may work. Tell me if you think this will accomplish my task. It's a brand called Dexin and it's model number is NDS3554. This unit looks similar to a PVI Micromod. I tried to post a direct link but it would not let me. The link below is correct once you remove the space after the h. Thanks.

http://english.dsdvb.com/news.php?mo...ssid=71&id=423

Last edited by DrDon; Today at 08:56 AM.
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post #172 of 173 Old Yesterday, 09:23 PM
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Dexin NDS3554 Spec Sheet with similar Info:
http://english.dsdvb.com/Upload/file...0319094736.pdf

Specs say all of the right things re Optional ATSC Modulator....but say NOTHING about HOW to build the PSIP information.....you should download User Manual and also contact their Tech Support for additional info.


I'm sure that people would be interested in HOW you can buy some....I saw many offers on Alibaba....and it MIGHT be on eBay....

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post #173 of 173 Old Today, 08:57 AM
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Threads merged.

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