Transcoding Video - Bitrate, Sampling Rate etc Limits?

[Leo48]

When encoding video, where to find guidelines as to basic settings like video bitrate, scale size, frames/sec, audio sampling frequency and bitrate?
I have e.g. MOV files from a digital camera
Video: MPEG-4, 640x480, 2600 Kbps, 15.000 fps
Audio: LPCM (Little unsigned), 63 Kbps, 1 channel, 7875 Hz, Resolution 8 bits.
I want to convert them to AVI, as some should be rotated and/or joined (the aim being standalone DVD-player), and I am not certain at all which settings make sense quality-wise (regardless of output file size).

TIA for any hint.

[Nelson37]

The number one rule is to change your source as little as possible, especially including re-encoding.

Your target of DVD standalone playback will require substantial changes, including a re-encode of a low-quality file.

The required framerate change to DVD spec is almost certainly a no-go item.

Leave the files as-is, burn them to disk as data for PC-only playback, or an HTPC.

If you want DVD standalone playback, you need to record in a format which is closer to DVD spec, framerate and resolution need to match at a minimum. Unless you enjoy watching really, really crappy video.

[tinker]

If you want to know all that, just look on left side of this window under "What is DVD"

[SLK001]

Yeah, what he said.

Your video would have to be scaled to 720x480 (or reduced to 352x240) to be DVD compliant. Your frame rate would have to be doubled to 30fps (by duplicating frames) to be DVD compliant. Your audio would have to be converted to 48kbps (16bit per sample) to be compliant.

None of these steps is really difficult, but I believe that your original source is of too poor of quality to be really suitable for a DVD. But your opinion is the only one that counts here.

You should learn how to use Avisynth. I would do all of the above (except the audio conversion) using Avisynth.

And there is plenty of info here on the board to answer virtually any question that you could have - certainly all of the ones you've asked today. Use the search feature.

[jagabo]

If you want to know all that, just look on left side of this window under "What is DVD"

That won't help him.

I have e.g. MOV files from a digital camera... I want to convert them to AVI...

For conversion to Divx AVI programs like Avi Demux or VirtualDub will work.

[SLK001]

If you want to know all that, just look on left side of this window under "What is DVD"

That won't help him.

I have e.g. MOV files from a digital camera... I want to convert them to AVI...

For conversion to Divx AVI programs like Avi Demux or VirtualDub will work.

Yes, it will, but if you really want to go to DVD, then skip the MOV->AVI step and instead go MOV->MV2 (or MV1).

[tinker]

If you want to know all that, just look on left side of this window under "What is DVD"

That won't help him.

I have e.g. MOV files from a digital camera... I want to convert them to AVI...

For conversion to Divx AVI programs like Avi Demux or VirtualDub will work.

Since the OP wanted avi to make DVD and know specifications, does not mean that it has to be DivX(mpeg4) file format, it could be avi uncompressed video for processing. As his spec show, he already has mpeg4 video.

[Leo48]

Thanks everybody for your input. A question or two remain, however, as I might not have expressed myself well.
When I need to rotate a file (which had been recorded inadvertently in portrait orientation), or join several videos into one, using e.g. AviDemux or SUPER, what are reasonable settings, and what are possible ones for the output file? Experimenting with the settings, I sometimes wind up with a mute video or with an unplayable one. Or with one that plays fine on my PC, but that FFmpeg refuses to encode to DVD?

Disregarding the later usage on DVD, for videos like the ones described in my first post, would it make sense to set the video bitrate for the output to 8000? And/or the frames to 25? Is it possible to go 44K and 128 bit for the audio with a source of 8K and 64 bit? Can I set 2 channels/16 bit when the source is only 1/8 bit, or would this even be a mistake?

Thank you for your time.

[tinker]

For PAL DVD 25fps. 8000kbs is fine, but it all depend on length (time) of the file and DVD capacity (single or double layer). You may have to lower bitrate for file to fit.
Audio has to be 48000 Hz, 16 or 24 bits. If AC3 audio format, than video bitrate can be higher, audio file is smaller than LPCM.
You can make stereo by copy mono channel to second channel or use splitter to feed audio to left and right inputs on your computer during download, easier.

[jagabo]

If you want to know all that, just look on left side of this window under "What is DVD"

That won't help him.

I have e.g. MOV files from a digital camera... I want to convert them to AVI...

For conversion to Divx AVI programs like Avi Demux or VirtualDub will work.

Since the OP wanted avi to make DVD and know specifications, does not mean that it has to be DivX(mpeg4) file format, it could be avi uncompressed video for processing. As his spec show, he already has mpeg4 video.

I'm Sorry. I assumed the OP was talking about putting (Divx) AVI files on a DVD. It looks like his goal is to make standard movie DVDs.

[manono]

I thought the same (glad I didn't join in). It looked to me like he had a DVD/MPEG-4 player that could play AVIs OK, and the final output was to be AVI. The point being that posters should provide as much information as possible as clearly as possible if they want as much help as possible.

It does beg the question of why convert to AVI at all (unless it's to a lossless intermediate AVI such as Lagarith or HuffYUV), as the whole thing can be done in one step in a single AviSynth script and encoded directly to MPEG-2 for DVD.

[tinker]

I'm Sorry. I assumed the OP was talking about putting (Divx) AVI files on a DVD. It looks like his goal is to make standard movie DVDs.

No harm done.
I understand that every time someone here ask about AVI, they want or have mpeg4 file.

As manono say, AviSynth was suggested to him also.

[Leo48]

It does beg the question of why convert to AVI at all

As I said earlier, I have a) files that need to be rotated and b) short clips which I would like to join (since they belong to the same scene). So I have to process them before I can feed them to a DVD encoder, that is the only reason why I convert them to AVI (much better quality than MOV -> MOV as produced by SUPER, the only app I could find that can do that). Is it preferable to choose MPG as the output format in this case?

(unless it's to a lossless intermediate AVI such as Lagarith or HuffYUV), as the whole thing can be done in one step in a single AviSynth script and encoded directly to MPEG-2 for DVD.

Thank you for these hints, will look into that. Might take a while before I come up with a working AviSynth script though.

[manono]

As I said earlier, I have a) files that need to be rotated and b) short clips which I would like to join (since they belong to the same scene).

For rotating, TurnLeft or TurnRight:

http://avisynth.org/mediawiki/TurnLeft

They'll probably have to be cropped and resized to match the rest after being rotated:

http://avisynth.org/mediawiki/Crop
http://avisynth.org/mediawiki/BicubicResize

And if they're interlaced, special allowances will have to be made.

Joining is also a simple matter in AviSynth:

http://avisynth.org/mediawiki/Splice

So I have to process them before I can feed them to a DVD encoder

And that's what your script will do for you.

If you're going to be doing a lot of this and are serious about producing good quality, it's certainly in your best interest to learn AviSynth.

[Leo48]

For rotating, TurnLeft or TurnRight:

http://avisynth.org/mediawiki/TurnLeft

Unfortunately this page is empty. No problem with the others.

If you're going to be doing a lot of this and are serious about producing good quality, it's certainly in your best interest to learn AviSynth.

Thank you so much for all your valuable hints. I intend to do this in a serious way and was wondering how, other than by clicking around in some GUI's. You gave me the shove I needed.

[guns1inger]

That page works for me. It doesn't contain any examples, but given these are single parameter, single function statements, there doesn't really seem a need.

[AlanHK]

For rotating, TurnLeft or TurnRight:

http://avisynth.org/mediawiki/TurnLeft

Unfortunately this page is empty. No problem with the others.

It works for me.

Anyway, that site uses Wikipedia code, just use its search box for any functions.

If you're going to be doing a lot of this and are serious about producing good quality, it's certainly in your best interest to learn AviSynth.

Thank you so much for all your valuable hints. I intend to do this in a serious way and was wondering how, other than by clicking around in some GUI's. You gave me the shove I needed.

For creating and editing Avisynth scripts, try AvsP.

[jagabo]

You script may be a simple as:

AviSource("x:\path\to\filename.avi")
TurnLeft()

That will take a 640x480 video and rotate it 90 degrees counterclockwise to give a 480x640 result. Use TurnRight() to rotate the other way.

480x640 is an illegal frame size for DVD so you'll want to resize it. MPEG2 for DVD also uses non-square pixels so you have to account for that:

AviSource("x:\path\to\filename.avi")
TurnLeft()
LanczosResize(400, 480)
AddBorders(160, 0, 160, 0)

That's for a 4:3 display aspect ratio NTSC DVD. The resizing is a little complex so use a program like FitCD to make the calculations for you. It can also generate the AVS script for you.

Finally, you have to convert the frame rate. This can be very tricky but the simplest solution is to use ChangeFPS()

AviSource("x:\path\to\filename.avi")
TurnLeft()
LanczosResize(400, 480)
AddBorders(160, 0, 160, 0)
ChangeFPS(29.97)

That will simply duplicate frames to create 29.97 fps out of 15 fps.

By the way, the AviSynth documentation is included with the installation. Use Start -> All Programs -> AviSynth 2.5 -> AviSynth Documentation.

[Leo48]

Thank you all again.

Slowly starting to get the hang of it ...
Blushing because of the remark about the 'empty' page.