Cap high then encode low or cap low first from hd source?

[yoda313]

Ok here's the dilema.

I bought a tv series thats 13 shows long and 24min each on a hd streaming service. I have the option to download it to my unit so playback stuttering is a non factor.

I am capping them to my hd pvr 1212 via component at 1080i and 5mb/s.

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Should I cap at the highest and then reencode with ripbot264 at cq 20 or 22?

Or should I cap at around 2 or 3 mb/s to get a low file size the first time?

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My goal is to get all 13 on a single 8gb micro sd card for viewing on my tablet (remember these are purchased, its just I can't access that service on my tablet hence the backup).

I know all reencoding involves a certain quality hit. However will it be better than capping really low initially with the hdpvr?

I'll be doing testing for sure with different scenarios.

I capped the first two episodes at 13mb/s and got a 2.3gb file. That was too extreme. I could only load a few shows on a sd card at that size.

I am currently capping the rest of the series at 5mb/s and I'm getting just under a 1gb each which is better.

Will I better off recapping all of them at 13mb or 13.5mb (13.5 mb/s is max for hdpvr) and then reencoding with ripbot264?

Or is starting at a lower cap at 5mb than encoding with ripbot264 the way to go? A smaller trip to the final destination?

I have yet to test a 2mb or 3mb cap so I don't know how pixellated it would be. Is that too low to go for a hd source?

Fyi I'm capping at 1080i off the unit via component.

Thanks for any suggestions.

Oh and I'll only be doing one encoding if I go really high and redo the captures. I know it would be totally stupid to reencode an encoded file. Thats why i want to try to target the best "source" file for my project.

Thanks everyone.

Also - stupid question - I'm sure i have one installed but I don't remember its name.

Whats a good h264 bitrate calculator?

Edit - also I haven't tested the 1080i cap yet on my tablet. How damaging to the quality would it be to encode a 1080i file to 720p if I decide not to recapture at 720p? (my playback unit can output at 720p fyi)

[jagabo]

Why do you bother asking this question since you can do the experiment yourself? How do you know CRF 20 or 22 is going to give you the size you need to fit all 13 episodes in 8 GB? 2000 to 3000 kbps is pretty low for 1080i material. My experience with the HD PVR is it looks pretty bad at bitrates that low. Is the show shot on film? If so, you'd be better off catpuring at as high a bitrate as you can (~15 Mb/s), inverse telecine, then encode with 2-pass VBR. You might even reduce the frame size to 720p. You may not even notice the difference on a tablet. You don't need an h.264 bitrate calculator. Bitrate is bitrate no matter what codec you use. So use any bitrate calculator.

[fritzi93]

I'd use at least 8 mb/s when capping 1080i with my HD-PVR. Normally, I cap 720p from the cable box at 3.7 mb/s (which happens to be the default bitrate for 720p with the Hauppauge).

It seems to me that your goal of fitting all the episodes onto an 8 GB microSD card is only reasonable if you resize to 720p resolution. So I'd cap high and resize/re-encode to 720p, to target size. Unless you reset your cable box to output 720p and cap at an appropriate bitrate for the desired size, thus avoiding a re-encode. The latter being preferable.

I use BitrateCalc. If I haven't made a mistake somewhere, and allowing for stereo AC3, you'd be looking at about 3 mb/s capping 720p. Which should be good enough on a tablet, IMO.

[yoda313]

How do you know CRF 20 or 22 is going to give you the size you need to fit all 13 episodes in 8 GB?

I was wrong its 12 episodes.

Actually I've gotten 200mb a show from a bluray rip of mine at cq 22 (24min ea) using ripbot so I assumed I'd get the same going this way with caps from the hdpvr.

Why do you bother asking this question since you can do the experiment yourself?

I'm looking to narrow the number of redos I could end up with.

Is the show shot on film?

It's an anime tv series so I don't think so.

My experience with the HD PVR is it looks pretty bad at bitrates that low. Is the show shot on film? If so, you'd be better off catpuring at as high a bitrate as you can (~15 Mb/s), inverse telecine, then encode with 2-pass VBR.

That's good to know. That is one thing I was looking to learn.

You don't need an h.264 bitrate calculator. Bitrate is bitrate no matter what codec you use. So use any bitrate calculator.

That I did not know. Thank you.

I'd use at least 8 mb/s when capping 1080i with my HD-PVR. Normally, I cap 720p from the cable box at 3.7 mb/s (which happens to be the default bitrate for 720p with the Hauppauge).

Thanks for the general info.

It seems to me that your goal of fitting all the episodes onto an 8 GB microSD card is only reasonable if you resize to 720p resolution. So I'd cap high and resize/re-encode to 720p, to target size. Unless you reset your cable box to output 720p and cap at an appropriate bitrate for the desired size, thus avoiding a re-encode. The latter being preferable.

That seems reasonable and in line with what jagabo was recommending.

FYI its a ps3.

I use BitrateCalc. If I haven't made a mistake somewhere, and allowing for stereo AC3, you'd be looking at about 3 mb/s capping 720p. Which should be good enough on a tablet, IMO.

Thanks. And yes it happens to be stereo not surround.

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I've decided to go ahead and output the ps3 to 720p and cap at near max to 13mb/s.

I'll then go ahead and do a conversion using cq22 (leaving it at 720p, though I am keeping my previous 1080i caps and I'll encode those to 720p when I do the set) I believe to hopefully ensure I'll get it on the card.

If I can't get close enough with decent quality at that level I can put fewer shows on. I'll just have to delete the first batch and copy the rest over after I go through the first group. But it would be desirable to have all 12 on the card at one time.

Thank you everyone.

[jagabo]

Can't you use a larger SD card? Prices are around 50 cents per GB now.

[yoda313]

Can't you use a larger SD card? Prices are around 50 cents per GB now.

Thanks for the suggestion.

What I'll do is keep my original captures in case my encodes don't look red-hot. Than I'll hop on ebay or amazon to check out larger cards.