[Jrmcgee]

Charles,

The reason why it’s difficult to grasp is the terminology here. It’s highly ambiguous. For instance, part of the MPEG 2 syntax (aside from what encoding options you chose), includes a HD-supportive Profile/Level: Main Profile/High Level(MP@HL). So, if you give it HD resolutions, it can encode them.(my assumption). Also, ” Final Cut Pro supports capture, editing, and output of high definition(HD) video when using an appropriate third-party capture card. 1080i, 1920×1080, 25,29.97(30fps), 59.94(60fps)
1080p “, etc. -Final Cut Pro 4.5 User Manual: I-26
So, even if I don’t “capture” but instead generate HD-resolutions, there is some ambiguity.
Finally, in the encoding summary for Compressor 1 I sent you, it says
Aspect Ratio 16:9 ( indicative of at least 720 resolution which is HD ).
However, you are correct that it doesn’t specify res. But, like I said before, MPEG 2 was inherintly designed to encode all ATSC-compliant resolutions by law:
ATSC compliant formats include:
1080 x 1920, 60 Hz interlaced, 30 Hz progressive
480 x 704, 60 Hz progressive/interlaced, 30 Hz progressive
720 x 1280, 60 Hz progressive, 30 Hz progressive
480 x 640, 60 Hz progressive/interlaced, 30 Hz progressive

You’re also making a good point about the maximum bit rate. Apparently the encoding techniques of compressor 1 are not quite sufficient to drive quality HD since minimum broadcast HD quality is done at 12-20 MBps.

[Jrmcgee]

DRW,

The Xbox 360 advertises that it understands and will stream MPEG-2 compressed High Definition Videos from a Windows Media Center PC to an HD-ready monitor or HDTV, resolutions up to 1080i.
Basically, I want to determine what they mean by “MPEG-2”. Intuitivly, it sounds like High Defintion images that are compressed using the MPEG-2 codec could be called “MPEG-2 HD”, and that the Xbox 360 would have no problem with it since it is HD output, which it supports.
However, I just want to verify that “there can only be one” when it comes to MPEG-2 data streams. In other words, that there are no flavors–that no matter what my encoding techniques ( Compressor 2 “MPEG-2 HD Support” ), the resulting stream is something that all ISO-standard hardware can understand if it can display HD-resolution in the first place.
The more I talk about it, the more I’m convinced it probably will. My argument is not, unfortunately, based on a Microsoft Xbox 360 Representative’s guarantee of those qualifications, but instead on the piecewise manner of MPEG 2 investigation done me. It’s frustrating.
Xbox 360 people refer me to Microsoft, and Microsoft vise reverse.

[Jrmcgee]

Thanks,

But, regardless of what encoding “technique” I use, the RESULTING MPEG 2 streams will be “structurally” identical, correct? Isn’t this what being an ATSC standard means? Thanks again!

[Jrmcgee]

Charles,

You see, I’m confused as to why Compressor I will not do a good job with HD Videos when it clearly has an encoding preset to do so:

Example of Compressor 1’s (BEST) MPEG-2 encoding syntax preset

Name: MPEG-2 60min High Quality Encode Widescreen
Description: 6.8 Mbps, 2-Pass VBR, 16:9
File Extension: m2v
Video Encoder
Format: M2V
Width and Height: Automatic
Pixel Aspect Ratio: default
Crop: None
Frame Rate: (100% of source )
Aspect Ratio: 16:9
Field Dominance: Auto detect
Average Data Rate: 6.8 (Mbps)
2 Pass VBR enabled
Maximum data rate: 7.5 (Mbps)
High Quality
Best motion estimation
Closed GOP Size: 1/2 second, Structure: IBBP
DVD Studio Pro meta-data enabled

[Jrmcgee]

Greetings,

Just wondering about “MPEG 2 HD”, and what one means by that. Is it just a way of saying HD Video that’s been compressed using MPEG 2 codec? Also, is there a difference between the following two MPEG 2 streams:
(1) 1920×1080 MPEG 2 Stream compressed using Compressor 1’s “MPEG-2 6min High Quality Encode Widescreen Preset”
(2) 1920×1080 MPEG 2 Stream compressed using a similar, but “HD supportive as advertised” MPEG-2 encoder?

Is there a difference in the resulting MPEG-2 stream as far as structure goes? Or will there JUST be some slight quality difference, per say?
By the way, MPEG-2 streams that come out of Final Cut Pro: are they program streams or transport streams?
Thanks!
v/r
JMcGee, Physics and Astronomy Undergrad,LSU
Visualizations Research

[Jrmcgee]

Simonson,

Let me display the query I sent to Microsoft to clarify things:

Greetings,

There seems to be a gap in Xbox 360’s advertisment of being able to understand MPEG2-compressed video.
What my group wants to do is the following. And we need to know, in writing, whether or not the Xbox 360/Windows Media Center PC combination can deliver:

(1) We computer-generate a High-Definition Video(e.g 1920×1080) on a Mac G5.
(2) We export the HD file using MPEG2 compression in Final Cut Pro 5.0’s ” Compressor 2 “,which boasts it
can ” provide support for enhanced MPEG-2 options for HD-resolution video formats up to
1920×1080, with bit rates up to 29 Mbps.”
(3) Then, the “specially” MPEG2-compressed HD movie will be sent to the Windows Media Center Edition PC
(4) We then use Media Center features to “Stream” this movie to the Xbox 360, which is on a 10/100 wired Ethernet Network with out PC

Q1: Will the Xbox 360 be able to understand such a stream?
Q2: Will the Xbox 360 stream that MPEG-compressed HD video to our HDTV *as an HD television signal*
Q3: Does the Xbox know “what to do” to convert the (PCdigital signal) to analogue (Xbox360 HD Component AV Cable) CORRECTLY (to preserve the HD MPEG2-compressed video at highest quality)

O2, you have no idea how hard it is to get certain questions answered about your hardware. It’s extremely difficult to pin down the facts. I hope you can help me with this ambiguity! Our research group appreciates any feedback or website pointing you can give us. We want to incorportate Microsoft products in our work, but it’s vital that we be sure of the output. The authenticity of it, as advertised.

Sincerely,
JMcGee, LSU Physics and Astronomy Undergrad

Simonson, the details in the above post are extremely important. The Xbox advertises “support” for stream HD video formats 720, 1080 etc, yes. But there is a difference between a digital computer signal and an HD television signal. I’m trying to eliminate the ambiguity of the MPEG 2 statement they make, that’s all. Those above questions are the ones that really need answering. Nice talking to you again, btw. wearebr.