HDR-CX350V. Should I encode to 720p?

[itsano]

Hi! I have the camcorder HDR-CX350V (http://goo.gl/vGEIE) and in the specs it says Video Resolution: HD: 1920 x 1080/60i

I am using Ripbot264 to encode the footage.

Would it make more sense to encode in 1920x1080 or 1080x720?

Thank you!

[nurbs]

That depends on what you want to do with it. If it's just about storage I'd keep the original. Since it's interlaced you'll have to deinterlace before you can resize, unless you only change the width. Deinterlacing 1080i is slow, especially if you use a good deinterlacer.

[Ghitulescu]

Would it make more sense to encode in 1920x1080 or 1080x720?If I would be forced to downscale I would use 1280x720p.

That depends on what you want to do with it. If it's just about storage I'd keep the original. Since it's interlaced you'll have to deinterlace before you can resize, unless you only change the width. Deinterlacing 1080i is slow, especially if you use a good deinterlacer.
No need to downsize/deinterlace it unless there's a sound reason. People that ask this kind of questions generally have a less-than-average knowledge of how deinterlacers and resizers work and they may severely damage the video. And if the source is gone, they may not recover the video in its initial state.

EDIT: Hopefully this is not a spam, see the link.

[Japhsoncross]

i have the same camcorder, it doesn't have enough pixels to recover full HD (ideal pixel count is 4.15mega, which CX550 has). i prefer deinterlace and resize it to 720p with tgmc.

[itsano]

I don't keep my originals (don't kill me for this!) once the videos are encoded. MTS files are way too big and since I end up archiving all my footage on a reliable online storage, size kinda matters in the long run and I also must say I'm very happy with the 720p quality. I also keep a copy of my videos on my WHS and stream them to my TV or upload them to my family as needed.

I do deinterlace my footage using RipBot264 (BFF --> 29.97 FPS). Am I right using BFF and not TFF?

But the 1080i confuses me as to how I should encode it. Can you deinterlace a 1080i source and end up with a 1920x1080 video or does it naturally must be resized to 1280x720?

Thanks for the input!

[nm]

I do deinterlace my footage using RipBot264 (BFF --> 29.97 FPS). Am I right using BFF and not TFF?

Depends on the footage. Usually 1080i is TFF. Write a simple AviSynth script with AssumeTFF().SeparateFields() and view it in a video player that supports single-frame stepping (although that's not strictly necessary in this case). If the motion is continuous frame-to-frame, your source is TFF. If it alternates between going forward and backward, it's BFF.

But the 1080i confuses me as to how I should encode it. Can you deinterlace a 1080i source and end up with a 1920x1080 video or does it naturally must be resized to 1280x720?

Some alternatives:

1. Keep the video interlaced.

+ No need to decide on a deinterlacer and output framerate.
- Deinterlacing on playback is not as good as proper deinterlacing during encoding.
- x264's support for interlaced encoding is not as efficient as progressive encoding.

2. Bob-deinterlace to 60p (1080i30 -> 1080p60)

+ Full 60 Hz temporal resolution: motion fluidity is the same as in the interlaced source.
+ Full spatial resolution (depending on the bobber).
- Requires a high bitrate.
- Playback may be difficult in many cases since 1080p60 is not Blu-ray compatible and many hardware decoders are not up to it.

3. Bob-deinterlace to 60p and resize to 1280x720

+ Full temporal resolution.
+ Blu-ray-compatible output. Decodable on hardware when encoded with L4.1-compatible settings.
+ Requires lower bitrate than alternatives 1 and 2.
- Some resolution might be lost, but that depends on the source quality. In practice the difference may not even be visible.
You can encode a test clip to both 720p60 and 1080p60 and load the files in an AviSynth script where the 720p clip is resized up to 1080p and then the clips are interleaved. Play back frame by frame to compare.

4. Deinterlace to 30p. Keep the resolution at 1920x1080 or resize to 1280x720.

+ Easy to encode and play back (especially 720p30). If you want to make fully Blu-ray-compatible streams, 720p30 needs repeat flags to make it appear 720p60.
- Temporal resolution is halved. You can get a film-like appearance by adding some motion blur with MVTools2. Otherwise it will look a bit jittery due to the fast shutter speed in the camera.


If you decide to deinterlace, choosing an appropriate (bob-)deinterlacing filter is very important. Try YadifMod+NNEDI2 or TDeint+NNEDI2. TGMC would be nice, but it's probably too slow for you. NNEDI2 is not that fast either, but it's much better than plain yadif.

[aegisofrime]

TGMC FTW. If you are going to do it, do it once and do it good. :)