What is the future of video and sound? The answer is... on the storage media! VCD, DVD, Blu-ray, HD DVD... I think you may familiar with these abbreviations, however, did you know their specifications and histories? Before knowing the future of sound, we can start with the historical journey of these storage media!
1. VCD, Video Compact Disc.
This is the first Digital media standard format in the world, established by Philips, Sony, JVC and Matsubushi. As its cost is low, now it spreads to the worldwide in a cheap price, and because of the low cost, easy to copy and without the protection of region code, VCD somehow still became a tool for pirate nowadays.
Let's see the basic specification of VCD:
1. VCD, Video Compact Disc.
This is the first Digital media standard format in the world, established by Philips, Sony, JVC and Matsubushi. As its cost is low, now it spreads to the worldwide in a cheap price, and because of the low cost, easy to copy and without the protection of region code, VCD somehow still became a tool for pirate nowadays.
Let's see the basic specification of VCD:
Audio Format: | MPEG-1 layer 2 |
Bit rate: | 224 kb/s |
Sample rate: | 44,100 Hz |
Number of Channels: | 2 (stereo) |
Video Format: | MPEG-1 |
Resolution: | 352×240 pixel /NTSC video 352×288 pixel /PAL video |
Frame rate: | 29.97 Hz (NTSC) 25 Hz (PAL) |
Bit rate: | About 1.13 Mbit/s |
As you can see, it resolution is so low and even the audio format is using mp2, not the one we most familiar with: MP3. The maximum minutes usually are 60 to 74 minutes, it means that it may not cover the whole in one disc, so it is common for VCD to have disc 1 and disc2.
Moreover, since it is using CBR(constant bit rate) for recording movie and audio, the quality of some complex scenes would be lower than VBR(variable bit rate). CBR means always use the same bit rate to encode something, VBR means the bit rates are changeable.
For example, to use the easiest example, like MP3, when you choose encoding some music or trans-coding from CD, after you use CBR for 320kbps, you will see the bit rates remain unchanged in the Windows Media Player or the other music player, like foobar2000. However, if you use VBR to encode the same music, you will found that the bit rate often changes, the lower for the quiet one, the higher for the complex one, like playing many musical instruments or echos at the same time.
Therefore, for the VCD, some complex scenes may not provide the best performance on screen.
2. SVCD, Super Video Compact Disc.
Since VCD's video and audio still have room for improving, the industries keep go ahead and create a new media called SVCD, Super Video Compact Disc. Just like its name, it is the super version of VCD.
Comparison between VCD and SVCD, let's see what it had improved!
Moreover, since it is using CBR(constant bit rate) for recording movie and audio, the quality of some complex scenes would be lower than VBR(variable bit rate). CBR means always use the same bit rate to encode something, VBR means the bit rates are changeable.
For example, to use the easiest example, like MP3, when you choose encoding some music or trans-coding from CD, after you use CBR for 320kbps, you will see the bit rates remain unchanged in the Windows Media Player or the other music player, like foobar2000. However, if you use VBR to encode the same music, you will found that the bit rate often changes, the lower for the quiet one, the higher for the complex one, like playing many musical instruments or echos at the same time.
Therefore, for the VCD, some complex scenes may not provide the best performance on screen.
2. SVCD, Super Video Compact Disc.
Since VCD's video and audio still have room for improving, the industries keep go ahead and create a new media called SVCD, Super Video Compact Disc. Just like its name, it is the super version of VCD.
Comparison between VCD and SVCD, let's see what it had improved!
Media: | VCD | SVCD |
Audio Format: | MPEG-1 layer 2 | MPEG-2 |
Bit rate: | 224 kb/s Cannot choose CBR/VBR | 32 to 384 kb/s Could choose CBR/VBR |
Number of Channels: | 2 (stereo) | 1 up to 5.1-channel |
Storage: | Up to 800MB | Up to 800MB |
Video Format: | MPEG-1 | MPEG-2 |
Resolution: | 352×240 pixel /NTSC video 352×288 pixel /PAL video | 480x480 /NTSC video 480x576 /PAL video |
| Bit rate | 1.13 Mb/s Cannot choose CBR/VBR | 2.6 Mb/s Could choose CBR/VBR |
As you can see, the specification of SVCD highly improved the flaw of VCD. Interestingly, the SVCD format were first created by the China government's China Recording Standards Committee, it is even earlier than Philips and Sony union: Video CD Consortium's new product — HQVCD. At last, the China Recording Standards Committee co-operated with Video CD Consortium and make the SVCD standard in 1998.
Normally, most of the DVD players are not compatible with SVCD but some of the China products or products from big brands support SVCD.
3. DVD, Digital Versatile Disc / Digital Video Disc
The most common format of the last generation and it is still widespread after the appearance of HD DVD and Blu-ray. As the space of DVD increased a lot, also video and audio codec keep improving from VCD, make DVD got a better image than VCD and SVCD.
4. HD DVD, High-Definition/Density DVD.
HD DVD means a evolution of DVD, a High-Definition DVD. It is created by DVD Forum, supported by Toshiba and Warner Bros. However, as the Warner Bros advocates Blu-ray later and the turnover of HD DVD dramatically drops, cause Toshiba to relinquish this format war and stop the production of HD DVD and its player in 2008.
5. The winner of this generation, Blu-ray.
5. The winner of this generation, Blu-ray.
It is a format developed by Blu-ray Disc Association, mainly lead by Sony and has became the winner of the format war in this generation.
To know their performance, look at their comparsion on this table!
Media | DVD | HD DVD | Blu-ray |
Audio Format | Dolby Digital (AC-3) DTS PCM(uncompressed sound/ lossless) MP1/MP2 | Dolby Digital Dolby Digital plus DTS-HD MPEG Audio (lossy above) DTS HD PCM MLP (lossless above) | Dolby Digital Dolby Digital plus DTS (lossy) PCM DTS HD Dolby TrueHD (lossless) |
Number of Channels: | 1-7.1-channels | 1-7.1-channels | 1-7.1-channels |
Storage: | Up to 4.7GB(single layer) | Up to 15GB (single layer) | Up to 25GB (single layer) |
Video Format: | MPEG2 | VC-1 H.264 MPEG2 | VC-1 H.264 MPEG2 |
Resolution: | 720×480 /NTSC Video 720×576 /PAL Video | 1920x1080 | 1920×1080 |
Bit rate | 9.8 Mb/s | 29.4 Mb/s | 40 Mb/s |
The future of video and sound? Lossless.
1. Dolby True HD
Click image to view its logo movie!
A lossless sound format developed by Dolby, according to its official specification, it has supported up to 14 channels and the maxium bitrates are doubled to 18Mb/s! Unlike Dolby's old products before, this TrueHD is lossless, it means that you can hear the raw, original sound from your home theatre with only one HDMI cable.
Technology Specifications
Sampling frequency: 44.1 kHz to 192 kHz
Sampling rate: Constant for all channels
Word length: Up to 24 bits
Blu-ray Disc™ channel support: Up to eight channels of 24-bit/96 kHz audio; designed to be expandable should the Blu-ray Disc standard adopt additional channels
Two- to six-channel support: Up to 24-bit/192 kHz
Maximum bit rate: Up to 18 Mbps on Blu-ray Disc
(Quoted from Dolby True HD website)
2. DTS HD
Click image to view its logo movie!
This is the product of DTS, it still compete with Dolby today. The DTS HD Master Audio is the rival of Dolby TrueHD as both of them support Blu-ray, HD DVD and they are lossless audio formats.
DTS-HD Master Audio Features
• Lossless Audio with variable data rates up to 24.5 Mbps for Blu-ray Disc and up to 18.0 Mbps for the
HD DVD format
• Up to 7.1 discrete channels with a sampling frequency of 96 kHz and 24 bits of signal resolution
• Up to 192 kHz sampling frequency and 24 bits of signal resolution for 2.0 channels
• Speaker Re-mapping with multiple speaker playback confgurations for 7.1 channel systems
• Secondary Audio/Sub Audio Stream for supplemental audio content
(Quoted from white paper of DTS HD)
As you can see, the resolution of video have a significant increase after the new generation of storage media's birth. Of course, so were the sound. From the oldest VCD to Blu-ray nowadays, the codec of sound or the sound system of these latest storage media had also undergone a big evolution.
Conclusion
As the generation tries to move on to high resolution and loseless audio, the trend of high definition would be continued by the industries. Maybe we can look forward the lossless video format for storage media in the next generation!
The finale of this series would be - 3D movies!
Wait for it!
Reference:
As the generation tries to move on to high resolution and loseless audio, the trend of high definition would be continued by the industries. Maybe we can look forward the lossless video format for storage media in the next generation!
The finale of this series would be - 3D movies!
Wait for it!
Reference:
Principles of digital audio by Ken C. Pohlmann, 2005, P.305
http://books.google.com.hk/books?id=VZw6z9a03ikC&pg=PA305
http://books.google.com.hk/books?id=VZw6z9a03ikC&pg=PA305
Technical Explanation of SVCD — Philips (pdf)
HD DVD, white paper in Japanese (pdf)
HD DVD - A Technical Introduction in English (PDF)
Warner Bros. Entertainment to Release Its High-Definition DVD Titles Exclusively in the Blu-Ray Disc Format Beginning Later This Year
Toshiba, ＨＤ ＤＶＤ事業の終息について
Dolby TrueHD official introduction
http://www.dolby.com/professional/technology/home-theater/dolby-truehd.html
DTS HD official introduction
http://www.dts.com/DTS_Audio_Formats/DTS-HD_Master_Audio.aspx
DTS HD official introduction
http://www.dts.com/DTS_Audio_Formats/DTS-HD_Master_Audio.aspx
White paper of DTS HD (pdf)
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