I am posting this because there are a lot of misconceptions about blu-ray floating around the Internet. It did not bother until after I read the White Papers off of the official blu-ray site and found out for my self the technical aspects of blu-ray. It was really surprising that most of the information about this technology is utterly fallacious. If you are interested in this technology, you should really read the 5 .pdf files on the website. If you choose not to I will give you a summary about this technology.
The only blu-ray format that is complete is BD-RE. This is where people get the, “Blu-ray only allows for mpeg2” statement. The truth is that every service provider company uses an mpeg2 transport stream. To encode an mpeg2 transport stream into a different codec at HDTV resolutions is not an easy task for hardware of today. They would have to start making specialized hardware for such a task, and the resulting picture quality would be inferior because it would have been taken from the mpeg2 transport stream and not the original source. This is the reason why the BDF (Blu-ray Disc Founders) chose mpeg2 for the BD-RE format. Also the BD-RE format is not locked down to just mpeg2 for future versions of the format. For instance, Voom is supposedly going to start using a more efficient codec for transmitting their signal to allow for more channels. If the BDF sees this as a good enough reason to include that codec in the BD-RE format they can if they want, but just because one small company does it doesn’t mean they will jump on the bandwagon.
The BD-ROM format is not complete. The BDF is working close to the studios to complete the format as we speak. If the studios decide that they will only use mpeg2, then blu-ray will hard a hard time justifying including another codec. The early version of this format was to use mpeg2 only because it was the codec that gave the best picture quality at the time. Given that at full data rate of 36mbps on a 50GB disk is just over 3 hours, it is plenty enough for pretty much every movie no matter what codec, so picture quality is the only determining factor. Look at the chart at the end of part3 of the .pdf files. The chart shows that only acceptable picture quality for both mpeg2 and mpeg4 was mpeg2 at 24mbps. Similar test was done with vc-9 and mpeg2 was chosen. This is why mpeg2 was originally the codec for this format as well, but since vc-9 and mpeg4 have made major improvement in PQ the BDF has chosen to give it another chance to be included.
Cost of blu-ray is also becoming more and more of a non-issue. Since TDK developed a new hard-coating and dropped the caddies (I actually liked the idea of caddies) for the BD-ROM format, the BDF has determined that it should cost the same if not less than a dvd5 to produce at mass volumes. The expense will actually come from retooling the equipment, which HD-DVD will also have to do. While the retooling to make blu-ray disk will cost more than retooling for HD-DVD, studios will have to retool all of their mpeg2 equipment to make use of the new codec of HD-DVD. So it’s either spend money on one or the other.
Blu-ray also has advantages in other areas as well.
1. Since blu-ray was made from ground up and not based on existed DVD technology, multiple layers are easier to do. DVD9 of today are basically a double-sided DVD that can be read from one side. It is extremely hard and expensive to create a true double-layered DVD, and since 2 layers on one side is extremely hard you rarely find a double-sided, double-layered DVD. With blu-ray this is not the case. TDK has developed a true quad layered blu-ray that is 100gb, and it would have no trouble doing that on a double-sided disk to increase it’s capacity to 200gb. Since HD-DVD is based on old DVD technology, it suffers from more that two layers so it is hard to get past the 30GB limit. This
2. Blu-ray was made for a rewriteable format first and foremost, so it is easier to use this technology as you would a VCR or a floppy disk. This convenience is truly a plus for the format, and combined with a capacity of 50-200GB on a single disk, it really a killer format for PC use.
3. Fast cost dropped is also a great possibility since blu-ray is strongly rumored to be used in the ps3. With millions of blu-ray drives and billions of disks being produced just for ps3, blu-ray can have a mass-market appeal rather quickly if marketed correctly.
4. 13 of the biggest CE companies backing it, enough said.
Also, no company beside CTS has officially backed any format.
The only blu-ray format that is complete is BD-RE. This is where people get the, “Blu-ray only allows for mpeg2” statement. The truth is that every service provider company uses an mpeg2 transport stream. To encode an mpeg2 transport stream into a different codec at HDTV resolutions is not an easy task for hardware of today. They would have to start making specialized hardware for such a task, and the resulting picture quality would be inferior because it would have been taken from the mpeg2 transport stream and not the original source. This is the reason why the BDF (Blu-ray Disc Founders) chose mpeg2 for the BD-RE format. Also the BD-RE format is not locked down to just mpeg2 for future versions of the format. For instance, Voom is supposedly going to start using a more efficient codec for transmitting their signal to allow for more channels. If the BDF sees this as a good enough reason to include that codec in the BD-RE format they can if they want, but just because one small company does it doesn’t mean they will jump on the bandwagon.
The BD-ROM format is not complete. The BDF is working close to the studios to complete the format as we speak. If the studios decide that they will only use mpeg2, then blu-ray will hard a hard time justifying including another codec. The early version of this format was to use mpeg2 only because it was the codec that gave the best picture quality at the time. Given that at full data rate of 36mbps on a 50GB disk is just over 3 hours, it is plenty enough for pretty much every movie no matter what codec, so picture quality is the only determining factor. Look at the chart at the end of part3 of the .pdf files. The chart shows that only acceptable picture quality for both mpeg2 and mpeg4 was mpeg2 at 24mbps. Similar test was done with vc-9 and mpeg2 was chosen. This is why mpeg2 was originally the codec for this format as well, but since vc-9 and mpeg4 have made major improvement in PQ the BDF has chosen to give it another chance to be included.
Cost of blu-ray is also becoming more and more of a non-issue. Since TDK developed a new hard-coating and dropped the caddies (I actually liked the idea of caddies) for the BD-ROM format, the BDF has determined that it should cost the same if not less than a dvd5 to produce at mass volumes. The expense will actually come from retooling the equipment, which HD-DVD will also have to do. While the retooling to make blu-ray disk will cost more than retooling for HD-DVD, studios will have to retool all of their mpeg2 equipment to make use of the new codec of HD-DVD. So it’s either spend money on one or the other.
Blu-ray also has advantages in other areas as well.
1. Since blu-ray was made from ground up and not based on existed DVD technology, multiple layers are easier to do. DVD9 of today are basically a double-sided DVD that can be read from one side. It is extremely hard and expensive to create a true double-layered DVD, and since 2 layers on one side is extremely hard you rarely find a double-sided, double-layered DVD. With blu-ray this is not the case. TDK has developed a true quad layered blu-ray that is 100gb, and it would have no trouble doing that on a double-sided disk to increase it’s capacity to 200gb. Since HD-DVD is based on old DVD technology, it suffers from more that two layers so it is hard to get past the 30GB limit. This
2. Blu-ray was made for a rewriteable format first and foremost, so it is easier to use this technology as you would a VCR or a floppy disk. This convenience is truly a plus for the format, and combined with a capacity of 50-200GB on a single disk, it really a killer format for PC use.
3. Fast cost dropped is also a great possibility since blu-ray is strongly rumored to be used in the ps3. With millions of blu-ray drives and billions of disks being produced just for ps3, blu-ray can have a mass-market appeal rather quickly if marketed correctly.
4. 13 of the biggest CE companies backing it, enough said.
Also, no company beside CTS has officially backed any format.
