DV AVI -> H 264 (bitrate and other settings)

[xprezons]

Hi,

I have a collection of PAL DV AVIs that I shot and would like to archive them. Following my research, I have settled on H 264 standard [using x264 codec (possibly using AviSynth or SUPER)], which from what I have come across so far, seems to hold the promise to become a widely accepted format (if not already).

My objective is to go for such encoding parameters as to keep video/audio quality as close to the original .avi footage as possible, stopping just about where higher values don't yield significant quality improvement.

I am feeling lost at the plethora of options in front to me with Video and Audio encoding ... Could anyone with good experience of this standard advise on a decent set of values that has held promise?

I would like to keep the resolution as is (720x576). I have been trying with average bitrate (video) of 2250Kbps. .. is this what most people prefer (with similar objectives in mind, of course)?

Apologies if I didn't post this on the correct forum. Seemed to me this was the appropriate place.

[jagabo]

h.264 is not a good choice for archiving. You will never be able to get back the details you are going to lose. But if you insist on using it:

Use CRF or CQP encoding (constant quality). Pick the quality (1/quantizer) you want and you will whatever bitrate is necessary for that particular video to achieve that quality (ie, the file will turn out as large as necessary). Many people consider a quantizer of ~18 to be near lossless. Higher values are lower quality (lower bitrate, smaller file). CQP is constant quality in a mathematical sense. CRF is constant quality in more of a visual sense -- and the resulting file will be smaller with the same quantizer.

If you don't care so much about file size disable B frames. B frames are encoded with lower quality to achieve better overall compression.

If you want easier seeking during playback reduce the GOP size. This will also cause your files to be a little larger.

Your DV AVI is likely interlaced. If so, be sure to encode interlaced.

[xprezons]

Thanks for your response. LOL you junked my research there. I'll accept that with the humility a newbie ought to have.

quick question

.. what is the best choice for archiving then, to reduce the DV AVI bloat but still retain the details?

I shall try out the suggestions with H 264 encoding parameters. Seems like a good choice for sharing videos with family. And have less coding formats to worry about.

One of the reasons for bending towards H 264 was that HD/Blu Ray seem to be using MPEG4 too. I haven't reached that far yet but I was inclined to think that I could import the H 264 encoded videos into HD projects in future and save on having to reencode. (Happy to stand corrected if this isn't right)

[jagabo]

what is the best choice for archiving then, to reduce the DV AVI bloat but still retain the details?

All high compression codecs get their compression by throwing away detail. If by "archiving" you mean storing your videos for posterity, you want to leave them as DV. Store the original tapes and store the DV AVI files on DVDs. Check them every year or two and make new copies if there is any sign of deterioration. If you simply want to have some convenient high quality format for watching h.264 is a good choice.

I could import the H 264 encoded videos into HD projects in future and save on having to reencode.

That will work -- in theory. I'm not up on Blu-ray specifics. Make sure it supports the resolution, bitrates, and other parameters with which you save. One thing to watch out for: constant quality encoding with high quality settings can result in bitrate peaks too high for some hardware decoders to handle.

[xprezons]

ok, for the footage that I absolutely must keep in original quality, I'm trying out writing back to tape as you suggested, jagabo.

in the below scenario .. is the original quality being retained, as I think should be happening?

Tape -> .avi capture using winDV (Type 2).
Trim clips using Avidemux (copy video, copy audio, save)
.avi -> Tape using winDV

For the remaining, I'm putting them through H 264.

Now, looking at the camcorder specs I suppose, yes the video is interlaced -> (URL). But I do not see any option on SUPER for interlaced. I converted one. it plays all right on VLC? Should I worry still?

I hope am not speaking absolute rubbish here ... Can someone please confirm if a video with the following details be used for Blu-ray authoring without requiring further encoding? Any suggestions are welcome.

Video:

encoding H.264/AVC using FFmpeg, x264
720x576, 25fps, bitrate 4032 kbps, H264 profile

Audio:

encoding AAC Main
Sampling freq 44.1kHz, 2 channels, bit rate 256 kbps

[poisondeathray]

Those specs are not compatible and will have to be re-encoded

"Blu-ray" specs are different than "AVCHD" compatible specs. AVCHD has a lower bitrate and vbv buffer. It's what is commonly used for content on DVD5.

I suggest you learn how to use megui and use the "AVCHD" profile - this will give you the presets (e.g. correct amount of vbv buffer, reference frames, nal, hrd ,etc....). Those streams can be authored without re-encoding (e.g. multiavchd can author a disc even with simple menus)

Currently there is an issue with displaying 4:3 aspect ratio content (like DV) on standalone devices - it doesn't display properly on standalone units but it's being worked on

Also AAC audio is "not legal" on the standalone units for avchd/blu-ray streams. Use AC3 if you want compatibility

I recommend editing the footage in DV as you have been doing , because editing AVCHD with frame accuracy is difficult at this point

Great info, links, tips, tutorials here, and the author is very helpful:
http://forum.doom9.org/showthread.php?t=143744

[jagabo]

in the below scenario .. is the original quality being retained, as I think should be happening?

Tape -> .avi capture using winDV (Type 2).
Trim clips using Avidemux (copy video, copy audio, save)
.avi -> Tape using winDV

Yes, what's left after trimming will lose no quality. The compressed frames will be copied directly from the source to the destination without reencoding.

For the remaining, I'm putting them through H 264.

Now, looking at the camcorder specs I suppose, yes the video is interlaced -> (URL). But I do not see any option on SUPER for interlaced. I converted one. it plays all right on VLC? Should I worry still?

I don't know what Super does when it converts interlaced DV to h.264. Open your DV source in AviDemux. You should be able to see interlace comb artifacts when there is motion in the video. Open your h.264 encoded video. Do you see the same comb artifacts?

If you encode interlaced you will preserve more of the temporal and spacial detail of your source. But you will want to use a deinteracing player to view the video on your computer. These usually don't do a great job of deinterlacing but at least your source is intact. As players get better at deinterlacing you will get better quality playback. Any set-top Blu-ray player and HDTV should be able to handle interlaced video.

There are many methods of deinterlacing. None of them is perfect, some are better than others. If you deinterlace the video now you will create a video that will forever have those imperfections. If you use AviSynth's TempGaussMC_beta1() bob deinterlacer (it's very slow but gives the best results I've see so far) now you will get better results than any player can give you now with on-the-fly deinterlacing. But 20 years from now Blu-ray players or HDTVs may be able to do a better job playing back an interlaced version.

[xprezons]

Thanks to you both for the inputs. I'll go away and try these out. This'll keep me busy for a while

[Hi8 newbie]

Jagabo, I understand that h.264 will loose information, but it doesn't seem like archiving as you suggest is practical for me and I assume many others. I have 40 2hr Hi8 tapes that need to be archived. Storing DV for these on DVDs would make for about 210 DVDs (at 27GB per 2 hour video in DV format). Also, checking all of them every year or two seems kinda like painting the Golden Gate bridge - as soon as I'm done I'd need to start over again. The original hi8 tapes are now nearing 20 years old, so I don't want to count on them for too much longer. Do you have another suggestion? I was planning on using h.264 at 4mbps so-as to have one DVD per 2 hour video.

what is the best choice for archiving then, to reduce the DV AVI bloat but still retain the details?

All high compression codecs get their compression by throwing away detail. If by "archiving" you mean storing your videos for posterity, you want to leave them as DV. Store the original tapes and store the DV AVI files on DVDs. Check them every year or two and make new copies if there is any sign of deterioration. If you simply want to have some convenient high quality format for watching h.264 is a good choice.

I could import the H 264 encoded videos into HD projects in future and save on having to reencode.

That will work -- in theory. I'm not up on Blu-ray specifics. Make sure it supports the resolution, bitrates, and other parameters with which you save. One thing to watch out for: constant quality encoding with high quality settings can result in bitrate peaks too high for some hardware decoders to handle.

[edDV]

Jagabo, I understand that h.264 will loose information, but it doesn't seem like archiving as you suggest is practical for me and I assume many others. I have 40 2hr Hi8 tapes that need to be archived. Storing DV for these on DVDs would make for about 210 DVDs (at 27GB per 2 hour video in DV format). Also, checking all of them every year or two seems kinda like painting the Golden Gate bridge - as soon as I'm done I'd need to start over again. The original hi8 tapes are now nearing 20 years old, so I don't want to count on them for too much longer. Do you have another suggestion? I was planning on using h.264 at 4mbps so-as to have one DVD per 2 hour video.

what is the best choice for archiving then, to reduce the DV AVI bloat but still retain the details?

All high compression codecs get their compression by throwing away detail. If by "archiving" you mean storing your videos for posterity, you want to leave them as DV. Store the original tapes and store the DV AVI files on DVDs. Check them every year or two and make new copies if there is any sign of deterioration. If you simply want to have some convenient high quality format for watching h.264 is a good choice.

I could import the H 264 encoded videos into HD projects in future and save on having to reencode.

That will work -- in theory. I'm not up on Blu-ray specifics. Make sure it supports the resolution, bitrates, and other parameters with which you save. One thing to watch out for: constant quality encoding with high quality settings can result in bitrate peaks too high for some hardware decoders to handle.

I captured all my Hi8 to DV format using a D8 camcorder and a Canopus ADVC-100*. Your 80 hours will store almost exactly to a 1TB drive (~$80). Buy two for backup.

The drive cost is small compared to the 80+ hours needed for dub. I did a tape a day when I could. I found about 30% of my stuff could be deleted after capture before archive. It took almost a year to get through my 100 plus Hi8 tapes. After all that work, I wouldn't consider a recode for archive. You can capture to MPeg2 in parallel using a PVR-250 or similar for an easier playback copy.


* My Hi8 camcorder was a Sony CCD-V5000 that recorded AFM and PCM digital audio tracks. The D8 camcorder couldn't read the PCM audio so I bought the ADVC. The ADVC was also useful for dubbing my Betacam-SP and 1" tapes.

[Hi8 newbie]

edTV,

Thanks for your suggestion. I'm hesitant to trust hard disks. Two is not so bad, but I've seen a lot of posts about drive failures, and these drives don't last much more than 5 years even when they are doing well.

[creamyhorror]

If you encode interlaced you will preserve more of the temporal and spacial detail of your source. But you will want to use a deinteracing player to view the video on your computer. These usually don't do a great job of deinterlacing but at least your source is intact. As players get better at deinterlacing you will get better quality playback. Any set-top Blu-ray player and HDTV should be able to handle interlaced video.

There are many methods of deinterlacing. None of them is perfect, some are better than others. If you deinterlace the video now you will create a video that will forever have those imperfections. If you use AviSynth's TempGaussMC_beta1() bob deinterlacer (it's very slow but gives the best results I've see so far) now you will get better results than any player can give you now with on-the-fly deinterlacing. But 20 years from now Blu-ray players or HDTVs may be able to do a better job playing back an interlaced version.

This suggestion of avoiding deinterlacing assumes you're looking for pristine quality - but in that case, surely the person wouldn't be encoding to another format in the first place? I submit that the imperfections of encoding will drown out any imperfections from a good deinterlacing anyway.

Hi8 newbie / exprezons: It all comes down to what exactly you want:

- Preserve footage in its original, pristine condition? Encode it to a lossless codec (buy more hard drives if you run out of space, and make backups). Here you'll never have to worry about the quality in future. You just have to put up with storage costs until drive technology becomes significantly cheaper and more durable.

- Store footage at low/medium/high quality, mainly for watching? Encode it to a lossy codec (e.g. H.264) at a suitable bitrate and compatibility setting. Here you're trading off quality for the ability to store the footage more cheaply. You don't need to worry much about storage costs, but your footage will always look like that.

If you want a balance between the two options, you can encode at a very generous bitrate that looks visually identical to the original for you. Any perceived quality 'loss' in the future will then result from either (1) much-improved playback deinterlacing or (2) an increase in your visual acuity and discrimination

I'm hesitant to trust hard disks. Two is not so bad, but I've seen a lot of posts about drive failures, and these drives don't last much more than 5 years even when they are doing well.

I think you should generally be transferring your footage to new drives when they near the end of their lifespan. By then hard drives will have gotten a lot bigger anyway.

[edDV]

edTV,

Thanks for your suggestion. I'm hesitant to trust hard disks. Two is not so bad, but I've seen a lot of posts about drive failures, and these drives don't last much more than 5 years even when they are doing well.

When you consider the additional time to encode and copy to optical media it becomes less likely you will complete the project.

I plan to dub these TB disks every few years. The cost will be small as drives get cheaper. The time to dub a TB drive is small compared to the alternative.

I'm currently dubbing my D8, MiniDV and HDV tapes as well that fill another two TB drives.

[creamyhorror]

Encoding 80 hours of footage will indeed take incredibly long, especially if you deinterlace properly. Not counting setup and preparation time, each hour of footage may take 3.5-7.5 hours to encode, depending on the deinterlacer and on whether you choose more or less efficient settings. You'll have to decide if you want to go that route given this.