I'm creating a commercial for broadcast cable that must have certain specs.

I start with a MKV clip that Kdenlive properties shows as 1920 x 1080. I want to preserve this size in the rendered M2T file.

When I render I select:
File rendering
NTSC
HDV
HDV 1080 60i (because the final file must be interlaced)

The result is an M2T file which is 1440 x 1080 (shown in Kdenlive clip properties).

I have 3 questions:
1) Why does this 1440 x 1080 M2T clip now seem to be the same visible size / aspect in my Kdenlive clip window as the original 1920 x 1080 MKV clip?
2) Am I losing quality?
3) How can I render at 1920 x 1080? I have tried creating a custom rendering profile with s=1920x1080, and Kdenlive shows the resulting M2T clip properties as indeed 1920 x 1080, however the clip now looks horizontally squished in the Kdenlive window and doesn't have the same visible dimensions or aspect.

Environment
============
Kdenlive 0.7.9 (5526)
FFmpeg version SVN-r201103092102
Melt 0.6.3

Thanks very much for your help.
--Stevej

Have you set up the project properties correctly? (Project>Project Settings)

My project profile is HD 1080i 29.97 fps.

1080i HDV has a fixed resolution of 1440x1080 - the pixels are not square which is why it still plays at the correct aspect ratio. If it is not 1440 pixels wide, then it might not be compatible with some HDV equipment, and will not, for example, record to HDV tape.

If you want it to be exactly 1920 you'll have to choose another format other than HDV. Does it have to be HDV?

Thanks for the info about pixel shape.

My goal is to create as high quality HD video as possible for a 30-second TV commercial. The camera shoots 1920 x 1080 60i (Panasonic HDC-TM55). I used Handbrake to convert this file to MKV. Kdenlive believes the MKV file to be 1920 x 1080. The rendered project is 1440 x 1080 but looks good to me on my 1920 x 1080 resolution monitor.

The specs from the broadcasters (Time Warner Cable Media) are:
========================================
MPEG-TS Parameters: (typical video size is 200MB to 600MB for :30 seconds) .m2t
GOP Sequence = IBBPBBPBBPBB
Video Profile = Mpeg4 1920X1080i with a ratio of 16/9 or 1280X720p with a ratio of 16/9
Video:  MPEG Video
Standard MPEG-TS Codec
29.97 Fps
6.4Mbs CBR or better
Enable Interlacing
Upper Field First
Motion Estimation Factor= 100
Enable GOP= Closed
Frame Mode= Interlaced Upper Field First
Audio:
AAC/MPEG1 Layer 2 or PCM
Audio mixed MONO or STEREO on both channels 1 and 2
========================================

I sent them the NTSC 1080 60i rendered video as a test, and they said it qualified.

As to your question, "does it have to be HDV?" I don't know. All I have is their specs.

Can you recommend a better project / rendering profile combination to generate these specs? Or are the ones I am using (project=HD 1080i, render=NTSC 1080 60i) the best?

I just can't help but feel I am losing quality in the translation to 1440 x 1080.

Thanks again!
--Stevej

It's anamorphic. http://en.wikipedia.org/wiki/Anamorphic_widescreen

Broadcast formats are classified by how many lines there are, so the actual width can vary for 1080i/p even though they are displayed the same.

Widescreen DVDs are the same way. Their resolution is the same as 4:3 DVDs but they are just displayed differently. Even 4:3 NTSC is anamorphic. (The ratio of 720x480 is NOT 4:3 even though it's displayed that way)

And yes, the quality is lower. Your horizontal resolution will be reduced. If you shot in "HE Mode" then your original source was 1440x1080 as well.

P.S. There is no such thing as NTSC 1080i60. This is ATSC. http://en.wikipedia.org/wiki/ATSC

Thanks for the heads-up on ATSC and the other information. My reference to "NTSC 1080 60i" is not my term. It's from Kdenlive, one of the pre-set file rendering modes.

Googling for Kdenlive and ATSC, I see older hits that reference the two together. In this version of Kdenlive I cannot find ATSC mentioned in either the project profiles or the render profiles.

Should they be there?

I agree with you that the "HE Mode" shoots in lower quality. However, I didn't shoot in "HE Mode". I shot in "HA 1920" record mode.

How can I preserve the 1920 x 1080 format while rendering to M2T with the specs in my original post? Is there a pre-set or do I need to create a custom render profile, and with what settings?


Or am I totally off-base here, and all broadcast-quality HD is really generated at 1440 x 1080?

Thanks so much for the assistance.
--Stevej

We renamed "ATSC" to "HD" in the project profiles a few versions ago.
HDV (which you asked Kdenlive to render) is 1440 and comes from HDV camcorders:
http://en.wikipedia.org/wiki/HDV

If you want ATSC 1920x1080, then use a HD 1080 project profile (not HDV) and render to MPEG-2. If they really insist on M2T (MPEG-2 Transport Stream) instead of program stream, which is what our MPEG-2 render presets output, then customize a MPEG-2 output and change the extension to m2t and the f= option to f=mpegts.

Thanks, Dan. That was very helpful and I followed your instructions.

I made a profile based off of MPEG2 8000k, rendered the video, and it looks good! The rendered video now reports 1920 x 1080. Woo hoo!

I've submitted this to Time Warner Cable for approval.

Then for fun, I rendered it as MPEG2 8000k, 12000k, 25000k. My eyes can't tell the difference. Do you have any guidance on when one is preferable over the others?

If you're interested, here's the YouTube version. It'll be up for awhile and then it will be gone.
http://www.youtube.com/user/myhumaninterface

Thanks again,
Stevej

The video looks good. It can be hard to say what bitrate to use. For 1080 HD MPEG-2, I definitely recommend over 10000k. DTV broadcasts are at about 12000k. However, your video might get transcoded before it gets placed into an ad server. So, something higher like 25000k is better; most HDV is 25000k.