firewire HD viewed as SD
Submitted by bic on February 6, 2008 - 8:12am
I have an oddity going on...it appears that I can record HD via firewire, but when I playback on a SD tv, I only here sound, no image. And yet, when I go from STB to SD tv, I can view HD fine. This is a SA4250.
Unfortunately, my system isn't on (at work), so I cannot try mplayer to see messages.
Sorry but you can't view HD
Sorry but you can't view HD on a SDTV. HD programs will not view on SD sets thats why you only hear sound. Your STB maybe HD but it will also push out SDTV programs and thats what your seeing. Not HD.
"Please ignore the man behind the curtain"
Dennis
"Please ignore the man behind the curtain"
Dennis
clarification
Sorry but you can't view HD on a SDTV. HD programs will not view on SD sets thats why you only hear sound. Your STB maybe HD but it will also push out SDTV programs and thats what your seeing. Not HD.
"Please ignore the man behind the curtain"
Dennis
so it sounds like the STB firewire is formatted for HD, where the STB cable coax is converting the HD down to SD format?
In other words, I should get an IR blaster and connect the coax cable from the STB to my tv card...?
Quote: so it sounds like
so it sounds like the STB firewire is formatted for HD, where the STB cable coax is converting the HD down to SD format?
No. HD format will not display on an analog TV. If you have a STB thats able to pull in HD channels then you must have an HDTV to view it. But your STB doesn't down convert to analog TV. Don't get a digital STB and an HDTV STB mixed up. They are two different things. A digital receiver means that the channel is much clearer but must come through a STB in order to be decrypted. It still able to be viewed on an analog TV. But an HD signal also has to be decrypted and must be viewed on an HD capable TV. Also keep in mind that an HD STB can view these digital and HD channels and that HD channels are usually are higher channel numbers away from the digital and any tue analog that you may have.
It sounds to me that you may have in fact recorded an HD program and are trying to view it on an analog TV which will not work. It's the same thing as me trying to view a HD channel with a non HD receiver and all I get is sound and no picture.
"Please ignore the man behind the curtain"
Dennis
"Please ignore the man behind the curtain"
Dennis
screen shot
No. HD format will not display on an analog TV.
If you have a STB thats able to pull in HD channels then you must have an HDTV to view it. But your STB doesn't down convert to analog TV.
ok the format will not be correct (not full resolution), but you can still watch it. As shown here, note "HDTV" in lower right. Cable box lights "HDTV" and "1080i" are illuminated.
Don't get a digital STB and an HDTV STB mixed up. They are two different things. A digital receiver means that the channel is much clearer but must come through a STB in order to be decrypted. It still able to be viewed on an analog TV. But an HD signal also has to be decrypted and must be viewed on an HD capable TV. Also keep in mind that an HD STB can view these digital and HD channels and that HD channels are usually are higher channel numbers away from the digital and any tue analog that you may have.
Yes digital STB and HDTV boxes are different.
Cable box in above photo was on channel 702.
firewire is set for HD
I took a firewire HD recording and set it to transcode. In mythbackend.log it shows Resizing from 1920x1088 to 544x480. But for some odd reason it fails.
Apparently, somehow the coax output of the STB converts down to SD format as I can view HD channels on my SD tv with that setup.
Not so fast!
Some STBs can receive an HDTV signal and downconvert it to 480i for an SDTV or VCR in real time. The Dish Network HD boxen can. But in order to do that the STB must contain a hardware chip to do the real-time transformation and that chip is not present in a PC. PCs can do software transcoding to accomplish the transformation, but that is definitely not a real-time process.
The posted image is clearly 480i SD, not 720p or 1080i HD. The proof of that is the visible scan lines in the image. They are practically invisible in a true 1080i image.
If you did record an HD program, you should be able to view it on a computer monitor.
understand now
Some STBs can receive an HDTV signal and downconvert it to 480i for an SDTV or VCR in real time. The Dish Network HD boxen can. But in order to do that the STB must contain a hardware chip to do the real-time transformation and that chip is not present in a PC. PCs can do software transcoding to accomplish the transformation, but that is definitely not a real-time process.
The posted image is clearly 480i SD, not 720p or 1080i HD. The proof of that is the visible scan lines in the image. They are practically invisible in a true 1080i image.
If you did record an HD program, you should be able to view it on a computer monitor.
Thanks, that's clear.
yep, I just tried an HD on my computer monitor and looks aok. Format size as vlc starts up shows 1920x1088.