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Bryan Sykora
HD MPEGs
on Nov 2, 2005 at 10:24:34 pm

a couple questions:
1. I have an HD MPEG from a client, that I can't get to play on my machine through Quicktime. It tells me it's not a file that Quicktime understands. Tried downloading the special MPEG2 quicktime codec from Apple, but no luck.

2. #1 becomes a problem because I have to deliver a project as the same format HD MPEG (1920x1080x59.94)... Anyone know the best way to make HD MPEGs? Starting with 3D files, render in Cinema 4D, composite and render in AfterEffects for specific hardware layout requirements, and then would compress as HD MPEG. Is there a good way to do directly exported from AfterEffects, rather than going the extra step of rendering and then compressing?

I've got a lot of specs I have to follow, so would need something that gives me advanced control of the compression.

Any ideas?

Thanks-
Bryan


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Ben Waggoner
Re: HD MPEGs
on Nov 3, 2005 at 12:10:03 am

Rhozet Carbon is my go-to tool for weird HD MPEG-2 projects. The only thing it can't do is AC-3 audio if you need an ATSC transport stream or something.

I know a painful amount about making HD MPEG-2 files - what spec are you shooting for?


My Book: http://www.benwaggoner.com/books.htm
Squeeze and ProCoder tutorials: http://www.classondemand.net/benwaggoner/
Compression Class at Stanford: http://www.digitalmediaacademy.org/compression.html


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Bryan Sykora
Re: HD MPEGs
on Nov 3, 2005 at 2:53:42 pm

thanks for the response-
below are specs...
looks like audio does have to be AC3... Seems like either Heuris or PixelTools compression software are 2 options, they're just extremely expensive... and thought there might be a better way to get to MPEG without rendering, compositing, rendering, compressing.
thought there might be something in Final Cut Pro HD, but can't find any info about HD MPEG possibility.

but my major issue: I can't play the original file that's currently playing on the system.
tried installing MPEG2 addon to quicktime, installing all Divx codecs, and on PC updating Windows Media, but nothing works.
Thought maybe the file was corrupt, but got an HD MPEG out of pixeltools demo export plugin, and I get the same error message with that also (not a file QT understands -2048).

Does HD MPEG assume MPEG 2 (It's not for DVD purposes)? Can't get an answer on that one.

Thanks again for your help-

MPEG specs are below:

* MPEG files must be encoded as a Transport Stream.
* Elementary Video stream must be Main Profile High Level MP@HL 4:2:0.
* Elementary Audio Stream must be AC3 encoded.
* Transport stream packet size is 188bytes. This is the standard size,
although some encoders generate
packets of 204 bytes. The extra data contains error detection
information, used for satellite transmission.
* Stream must start with an I frame and finish on a 188 bytes packet
boundary.
* The two most popular resolutions supported are 1920 x 1080 x 59.94
interlace and 1280 x 720 x 59.94
progressive.
* Recommended Video PID numbers are 17, 33 & 49. Audio PID numbers are
video PID + 3. Try to ensure
that all files are encoded with the same PID. MediaSonic normally use
49.
* The standard ATSC bit rate is 19.39Mb/s. Higher bit rates up to 50Mb/s
can be accommodated.25Mb/s is
an excellent compromise between image quality and file size (storage).
* It is preferable to use closed Group of Pictures (GOPs) if this option
is available with the encoder. The
preferred, though not required, GOP size is 15 frames. This provides a
good compromise between
compression and random access in the stream.
* A GOP pattern containing I, B & P frames will provide the most
efficient compression.
I B B P B B P... generally produces good results.
* Each GOP should contain a sequence header.


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Gen Kiyooka
Re: HD MPEGs
on Nov 4, 2005 at 6:00:53 pm

If your system has the CPU horsepower to render the stream, then VideoLAN client will be able to play it when noone else can.

http://www.videolan.org

Gen Kiyooka
Digigami


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Charles Simonson
Re: HD MPEGs
on Nov 4, 2005 at 8:49:44 pm

I'll second VLC or MPlayer to try and play the stream you currently have. If VLC will not play your MPEG-2 file, then its hard to imagine what will. I have worked with some very odd formats, and while VLC doesn't always do a bang up job with the audio playback, the video is usually well handled.

Per encoding streams to match the spec, I would suggest taking a look at the MainConcept encoder for the video. The specs you listed do not seem that odd to achieve, and the Rhozet encoder will also be able to generate those as Ben suggested. For the audio, while the Rhozet and the MainConcept encoders will not do AC-3 encoding, there are plenty of affordable small apps for encoding AC-3. And you should be able to mux the two streams into a transport packet with the apps from Womble on the PC or maybe even MPEGStreamClip for the mac.


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Tim Kolb
Re: HD MPEGs
on Nov 7, 2005 at 2:22:53 pm

[Bryan Sykora] "MPEG specs are below:

* MPEG files must be encoded as a Transport Stream.
* Elementary Video stream must be Main Profile High Level MP@HL 4:2:0.
* Elementary Audio Stream must be AC3 encoded.
* Transport stream packet size is 188bytes. This is the standard size,
although some encoders generate
packets of 204 bytes. The extra data contains error detection
information, used for satellite transmission.
* Stream must start with an I frame and finish on a 188 bytes packet
boundary.
* The two most popular resolutions supported are 1920 x 1080 x 59.94
interlace and 1280 x 720 x 59.94
progressive.
* Recommended Video PID numbers are 17, 33 & 49. Audio PID numbers are
video PID + 3. Try to ensure
that all files are encoded with the same PID. MediaSonic normally use
49.
* The standard ATSC bit rate is 19.39Mb/s. Higher bit rates up to 50Mb/s
can be accommodated.25Mb/s is
an excellent compromise between image quality and file size (storage).
* It is preferable to use closed Group of Pictures (GOPs) if this option
is available with the encoder. The
preferred, though not required, GOP size is 15 frames. This provides a
good compromise between
compression and random access in the stream.
* A GOP pattern containing I, B & P frames will provide the most
efficient compression.
I B B P B B P... generally produces good results.
* Each GOP should contain a sequence header."



It looks to me like your client wants you to encode their distribution file for them. a 19+ Mb transport stream MPEG2 is typical of satellite transmission files (as the spec indicates). I would think the applications mentioned would play it, or POSSIBLY something that would handle HDV might load it, though the framesize/datarate combo is not HDV spec.




TimK,

Kolb Syverson Communications,
Creative Cow Host,
2004-2005 NAB Post Production Conference
Premiere Pro Technical Chair,
Author, "The Easy Guide to Premiere Pro" http://www.focalpress.com
"Premiere Pro Fast Track DVD Series" http://www.classondemand.net


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