drbuzz0
14th February 2013, 18:16
This is a guide I wrote some time ago. - Hope it is helpful
The most common way of recording HDTV signals is by capturing the output of a receiver, such as a satellite or cable box. This is most often done via the analog component video output. In some cases, however, the DVI/HDMI signal may be unencrypted, in which case, it can be used, with the appropriate capture adapter.
Unfortunately, capturing the decoded output has some major disadvantages.
- You are forced to transcode the signal and re-encode it after decoding. You do not keep the signal at the original quality
- The decoder may apply some post-processing to the signal, which can be undesirable or limit your options for re-encoding it. Capturing the raw signal lets you have full control over how it is decoded and any post-processing applied
- You don’t know the bit rate and therefore you can end up using too high or too low a level of compression for your capture. TV stations sometimes throttle down their bit rate, and you may end up capturing it at a higher bit rate than the original one, which is wasteful. You also have no objective way of knowing the quality.
- The same is true of resolution. 1080i/1080p signals are sometimes broadcast at 1440×1080 rather than 1920×1080, but it’s hard to tell. You may be left thinking “gee. This capture seems not quite as sharp as I had hoped. Is it just me or is this ‘hd light’.”
- If capturing from analog output, there is additional quality loss.
Therefore, the best way to capture is to get the real, raw, unencrypted but otherwise undecoded transport stream. Here’s how you can do it:
From Over the Air TV (ATSC):
With a tuner card - There are many ATSC tuner cards available. PCI, PCI-Express, USB, ExpressCard formats are available. This is quite easy. All freely broadcast over the air channels can be recorded with relative ease.
With an ATSC tuner with a firewire output – A few ATSC tuners exist that include a firewire output. The signal can be captured via firewire. They are hard to find, however, and probably are not the best solution.
From Digital Cable Television:
With an QAM-Capable Tuner Card – Many of the OTA tuners out there now support for QAM modulated signals. The difference between HD over digital cable and over the air is that OTA broadcasts use 8VSB modulation, while digital cable uses QAM. Not all HD tuners will receive QAM Signals, but some will.
This will ONLY work with UNENCRYPTED channels. These are the basic cable channels that you do not need to pay anything extra. How many unencrypted channels you have will depend on your system. Local broadcast channels (ABC, NBC, CBS, Fox etc) are almost always unencrypted. Basic cable channels like USA, TNT, TBS are often, but not always, unencrypted. This method will NOT work at all on channels like HBO or anything else beyond the most basic level of programing.
With a CableCard Tuner – A few tuners exist that allow you to use a validly subscribed cablecard, which you can get from your cable company. These tuner cards will receive all the programing you pay for on your subscription, but there is an unfortunate catch.
The only programs that can be watched freely and recorded to unencrypted files are those which are flagged as “copy freely” and do not have copy protection enforced on them. If copy protection is enforced the cablecard tuner will not allow you to watch or record the programing using any non-approved software. Because of this, standard recording software will not work at all. The only thing that will work is Windows Media Center, which will only record the shows to encrypted DRM’ed files. This, of course, defeats the whole purpose.
To what extent programing is copy protected depends on the network and the cable provider. Some networks specify full copy protection, but not all cable companies enforce it. Some cable companies don’t enforce copy protection at all, but they are few and becoming fewer. Some copy protect everything, which means cablecard tuners are all but useless. Most apply DRM to some but not all programing. It’s mostly the luck of the draw.
With a cable box with Firewire out – Most newer cable boxes have a firewire port, but if you have an older model, you can ask your cable company to upgrade you to a new one. The FCC requires that cable companies provide a firewire cable box if you request it. The cable box will, obviously, receive all the channels you are subscribed to.
Unfortunately, like cablecard, there is a catch. Firewire recordings may also be copy protected. If they are, they will be encrypted with a protocol called DTCP (digital transmission copy protection) and you will not be able to view or record them freely with capture software. Instead, they will only be viewable and recordable with approved devices that include DRM support and encrypt the files.
The same rules as with cablecard apply. Some cable companies have not enabled DRM in their systems, but most have. How much of the content is DRM-protected is highly variable. It is really hit or miss.
With a Nextcom-modified cable box - This is one of the most expensive solutions, but it is also one of the most flexible. A company called Nextcom Wireless offers modifications to digital cable boxes which adds a USB-2.0 interface for connection to PC’s. With this modification, all digital channels can be recorded without encryption. This will work for all channels you have a valid subscription to and can view.
There are, however, a few requirements. First, this will only work with Motorola-based digital cable systems. There are two main formats for digital cable in the United States. Some use Motorola (formerly General Instruments) equipment and some use Scientific Atlanta equipment. If your cable company uses the Scientific Atlanta system, you are out of luck.
The first thing you have to do is acquire a Motorola brand cable box that DOES NOT have firewire. The newer ones with firewire are not modifiable. You can buy one of these on eBay. You will then have to convince your cable company to authorize the box for a subscription on their system. Most boxes are leased and some cable companies are difficult to get to authorize a customer-owned box. However, you should be able to get them to do so, though it might take some convincing. Alternatively you could try to see if your cable company will lease you an older box without firewire.
Once you have confirmed that you can get the older non-firewire box to work with your cable system, you have to send it to Nextcom to be modified with the additional USB port (they can do it in a reversible manner without drilling holes, if the box is leased), or you can order the modification kit from them and do it yourself.
The cost of the kit is $279.95
The cost to have your unit modded is $599.95
With commercial equipment – This is a long shot and, if possible, will be very expensive. Both Motorola and Scientific Atlanta make commercial digital cable receivers intended for use in circumstances where the signal is being re-encoded or fed into another system, such as at a large hotel, a college campus etc. These boxes output the signal via an ASI or SPI interface.
If you can find one of these, which is difficult, as they are not sold to the general public, expect to pay quite a lot for it. You will next need to get your cable company to authorize it, which is also likely to prove difficult.
You will then need an adapter to capture the raw transport stream signal into your computer. About the cheapest you are likely to find is the DTVWorks SPI interface, which costs $399.99. However, it only works with the SPI interface, which is less common than SPI and has some compromises, such as little buffer memory. For more advanced interfaces and those that support the ASI format, expect to pay over one thousand dollars.
From Dish Network:
With a Nextcom Modified Dish Network Receiver - In addition to modifying Motorola digital cable equipment, Nextcom offers a similar modification for Dish Network receivers. The functionality is the same – a USB 2.0 port will allow recording of all channels, HD and SD. Note that the system does NOT work with all Dish Network receivers, so check their site to make sure you get a compatible receiver. As with digital cable boxes, the cost is $279.99 for a self-install kit. Having them do the modification costs between $469.95 and $549.95 depending on the receiver.
With a PC DVB Tuner - Officially, Dish Network service is only available for use with their own brand receivers. However, Dish Network uses the DVB-2 standard for satellite broadcasts and can therefore, in principle, be received by a DVB-S2 tuner, tuners are available in PCI, USB and other formats.
However, Dish Network will not authorize the use of non-brand equipment and therefore, even if you have a subscribed access card, some level of circumvention of their access control is required, even if only to allow the valid card to work with the tuner. Because this topic flies very close to signal theft, it will not be discussed further here, other than to say it has been done.
With a Professional Echostar Receiver with DVB Output - Echostar, the parent company of Dish Network does make a series of commercial receivers that can be subscribed to the Dish Network service. These receivers are intended for headends and other locations which would require a raw output of the transport stream. They tend to be expensive and may be hard to find. As with commercial digital cable receivers, a DVB-ASI or DVB-SPI interface will be required, which is also very expensive.
From Free to Air Satellite:
With a PC Receiver – There are a number of stations broadcast by satellite in DVB format and unencrypted. These include international content, shopping channels, public television and other content. A few network feeds can also be found on free satellite. These are easily received with a USB, PCI or PCI Express receiver. There are two types of receivers: DVB-S receivers and newer DVB-S2 receivers. DVB-S2 receivers include support for new modulation types that were not supported by the original DVB-S standard. Increasingly, feeds are moving to the more efficient DVB-S2 standard.
With a standalone receiver - There are a number of DVB/FTA receivers out there that feature network interfaces and a few with firewire. These can be used to capture the transport stream and send it to a computer.
The "Dreambox" is a receiver that uses a Linux-based operating system and is known for being highly configurable and open to home-brew modifications. It is popular with hobiests.
From DirecTV:
With a Commercial Receiver and an SPI or ASI interface – DirecTV is far and away the most difficult source to get a transport stream from. Their equipment is totally proprietary. Previous generations of receivers could be modified to tap the unencrypted stream, but this is not possible with the current mpeg-4 receivers and content. LG makes a series of DirecTV receivers that support HD and Mpeg-4 content and have an ASI output. This can be subscribed to DirecTV and the content can be captured with an ASI capture interface. If you are very very lucky, you may be able to get one of these second hand for a few hundred. The cost to buy one new unit is about $1400, plus the cost of the ASI interface, which will be more than one thousand dollars.
It is uncertain whether DirecTV would allow one of these receivers to be subscribed to normal consumer programing packages. They may require more limited subscriptions, as these are normally intended for headend use. Also, while encryption of the output is optional, its possible that DirecTV would mandate this option be enforced for a subscription.
The most common way of recording HDTV signals is by capturing the output of a receiver, such as a satellite or cable box. This is most often done via the analog component video output. In some cases, however, the DVI/HDMI signal may be unencrypted, in which case, it can be used, with the appropriate capture adapter.
Unfortunately, capturing the decoded output has some major disadvantages.
- You are forced to transcode the signal and re-encode it after decoding. You do not keep the signal at the original quality
- The decoder may apply some post-processing to the signal, which can be undesirable or limit your options for re-encoding it. Capturing the raw signal lets you have full control over how it is decoded and any post-processing applied
- You don’t know the bit rate and therefore you can end up using too high or too low a level of compression for your capture. TV stations sometimes throttle down their bit rate, and you may end up capturing it at a higher bit rate than the original one, which is wasteful. You also have no objective way of knowing the quality.
- The same is true of resolution. 1080i/1080p signals are sometimes broadcast at 1440×1080 rather than 1920×1080, but it’s hard to tell. You may be left thinking “gee. This capture seems not quite as sharp as I had hoped. Is it just me or is this ‘hd light’.”
- If capturing from analog output, there is additional quality loss.
Therefore, the best way to capture is to get the real, raw, unencrypted but otherwise undecoded transport stream. Here’s how you can do it:
From Over the Air TV (ATSC):
With a tuner card - There are many ATSC tuner cards available. PCI, PCI-Express, USB, ExpressCard formats are available. This is quite easy. All freely broadcast over the air channels can be recorded with relative ease.
With an ATSC tuner with a firewire output – A few ATSC tuners exist that include a firewire output. The signal can be captured via firewire. They are hard to find, however, and probably are not the best solution.
From Digital Cable Television:
With an QAM-Capable Tuner Card – Many of the OTA tuners out there now support for QAM modulated signals. The difference between HD over digital cable and over the air is that OTA broadcasts use 8VSB modulation, while digital cable uses QAM. Not all HD tuners will receive QAM Signals, but some will.
This will ONLY work with UNENCRYPTED channels. These are the basic cable channels that you do not need to pay anything extra. How many unencrypted channels you have will depend on your system. Local broadcast channels (ABC, NBC, CBS, Fox etc) are almost always unencrypted. Basic cable channels like USA, TNT, TBS are often, but not always, unencrypted. This method will NOT work at all on channels like HBO or anything else beyond the most basic level of programing.
With a CableCard Tuner – A few tuners exist that allow you to use a validly subscribed cablecard, which you can get from your cable company. These tuner cards will receive all the programing you pay for on your subscription, but there is an unfortunate catch.
The only programs that can be watched freely and recorded to unencrypted files are those which are flagged as “copy freely” and do not have copy protection enforced on them. If copy protection is enforced the cablecard tuner will not allow you to watch or record the programing using any non-approved software. Because of this, standard recording software will not work at all. The only thing that will work is Windows Media Center, which will only record the shows to encrypted DRM’ed files. This, of course, defeats the whole purpose.
To what extent programing is copy protected depends on the network and the cable provider. Some networks specify full copy protection, but not all cable companies enforce it. Some cable companies don’t enforce copy protection at all, but they are few and becoming fewer. Some copy protect everything, which means cablecard tuners are all but useless. Most apply DRM to some but not all programing. It’s mostly the luck of the draw.
With a cable box with Firewire out – Most newer cable boxes have a firewire port, but if you have an older model, you can ask your cable company to upgrade you to a new one. The FCC requires that cable companies provide a firewire cable box if you request it. The cable box will, obviously, receive all the channels you are subscribed to.
Unfortunately, like cablecard, there is a catch. Firewire recordings may also be copy protected. If they are, they will be encrypted with a protocol called DTCP (digital transmission copy protection) and you will not be able to view or record them freely with capture software. Instead, they will only be viewable and recordable with approved devices that include DRM support and encrypt the files.
The same rules as with cablecard apply. Some cable companies have not enabled DRM in their systems, but most have. How much of the content is DRM-protected is highly variable. It is really hit or miss.
With a Nextcom-modified cable box - This is one of the most expensive solutions, but it is also one of the most flexible. A company called Nextcom Wireless offers modifications to digital cable boxes which adds a USB-2.0 interface for connection to PC’s. With this modification, all digital channels can be recorded without encryption. This will work for all channels you have a valid subscription to and can view.
There are, however, a few requirements. First, this will only work with Motorola-based digital cable systems. There are two main formats for digital cable in the United States. Some use Motorola (formerly General Instruments) equipment and some use Scientific Atlanta equipment. If your cable company uses the Scientific Atlanta system, you are out of luck.
The first thing you have to do is acquire a Motorola brand cable box that DOES NOT have firewire. The newer ones with firewire are not modifiable. You can buy one of these on eBay. You will then have to convince your cable company to authorize the box for a subscription on their system. Most boxes are leased and some cable companies are difficult to get to authorize a customer-owned box. However, you should be able to get them to do so, though it might take some convincing. Alternatively you could try to see if your cable company will lease you an older box without firewire.
Once you have confirmed that you can get the older non-firewire box to work with your cable system, you have to send it to Nextcom to be modified with the additional USB port (they can do it in a reversible manner without drilling holes, if the box is leased), or you can order the modification kit from them and do it yourself.
The cost of the kit is $279.95
The cost to have your unit modded is $599.95
With commercial equipment – This is a long shot and, if possible, will be very expensive. Both Motorola and Scientific Atlanta make commercial digital cable receivers intended for use in circumstances where the signal is being re-encoded or fed into another system, such as at a large hotel, a college campus etc. These boxes output the signal via an ASI or SPI interface.
If you can find one of these, which is difficult, as they are not sold to the general public, expect to pay quite a lot for it. You will next need to get your cable company to authorize it, which is also likely to prove difficult.
You will then need an adapter to capture the raw transport stream signal into your computer. About the cheapest you are likely to find is the DTVWorks SPI interface, which costs $399.99. However, it only works with the SPI interface, which is less common than SPI and has some compromises, such as little buffer memory. For more advanced interfaces and those that support the ASI format, expect to pay over one thousand dollars.
From Dish Network:
With a Nextcom Modified Dish Network Receiver - In addition to modifying Motorola digital cable equipment, Nextcom offers a similar modification for Dish Network receivers. The functionality is the same – a USB 2.0 port will allow recording of all channels, HD and SD. Note that the system does NOT work with all Dish Network receivers, so check their site to make sure you get a compatible receiver. As with digital cable boxes, the cost is $279.99 for a self-install kit. Having them do the modification costs between $469.95 and $549.95 depending on the receiver.
With a PC DVB Tuner - Officially, Dish Network service is only available for use with their own brand receivers. However, Dish Network uses the DVB-2 standard for satellite broadcasts and can therefore, in principle, be received by a DVB-S2 tuner, tuners are available in PCI, USB and other formats.
However, Dish Network will not authorize the use of non-brand equipment and therefore, even if you have a subscribed access card, some level of circumvention of their access control is required, even if only to allow the valid card to work with the tuner. Because this topic flies very close to signal theft, it will not be discussed further here, other than to say it has been done.
With a Professional Echostar Receiver with DVB Output - Echostar, the parent company of Dish Network does make a series of commercial receivers that can be subscribed to the Dish Network service. These receivers are intended for headends and other locations which would require a raw output of the transport stream. They tend to be expensive and may be hard to find. As with commercial digital cable receivers, a DVB-ASI or DVB-SPI interface will be required, which is also very expensive.
From Free to Air Satellite:
With a PC Receiver – There are a number of stations broadcast by satellite in DVB format and unencrypted. These include international content, shopping channels, public television and other content. A few network feeds can also be found on free satellite. These are easily received with a USB, PCI or PCI Express receiver. There are two types of receivers: DVB-S receivers and newer DVB-S2 receivers. DVB-S2 receivers include support for new modulation types that were not supported by the original DVB-S standard. Increasingly, feeds are moving to the more efficient DVB-S2 standard.
With a standalone receiver - There are a number of DVB/FTA receivers out there that feature network interfaces and a few with firewire. These can be used to capture the transport stream and send it to a computer.
The "Dreambox" is a receiver that uses a Linux-based operating system and is known for being highly configurable and open to home-brew modifications. It is popular with hobiests.
From DirecTV:
With a Commercial Receiver and an SPI or ASI interface – DirecTV is far and away the most difficult source to get a transport stream from. Their equipment is totally proprietary. Previous generations of receivers could be modified to tap the unencrypted stream, but this is not possible with the current mpeg-4 receivers and content. LG makes a series of DirecTV receivers that support HD and Mpeg-4 content and have an ASI output. This can be subscribed to DirecTV and the content can be captured with an ASI capture interface. If you are very very lucky, you may be able to get one of these second hand for a few hundred. The cost to buy one new unit is about $1400, plus the cost of the ASI interface, which will be more than one thousand dollars.
It is uncertain whether DirecTV would allow one of these receivers to be subscribed to normal consumer programing packages. They may require more limited subscriptions, as these are normally intended for headend use. Also, while encryption of the output is optional, its possible that DirecTV would mandate this option be enforced for a subscription.