DVD audio quality

[Gerax]

Hi all

I'm just wrapping a project, (double bass and piano playing various Bottesini and Fryba tunes) which I recorded and edited; video was also recorded (not on a professional level, but acceptable). Now, the issue. I've been asked to edit video too (it's for a simple web release, no DVD), which I did in Vegas Pro. The problem is that after rendering the final edit with my finished audio (recorded with Schoeps mics in a good hall, edited and mixed in PT) i found that Mpeg compression for DVD (256KBps, 48KHz) is messing with the sound in a very annoying way...
This is not my first audio for video job, but I've always let the final encode to the video guys who supposedly have better tools for this task...
What would you use (on PC) to assemble the finished video and audio so that the sound isn't so smeared and not true to my original recording?
Any particular settings I should be aware of?

Thanx

L.G.

[Roland]

For video editing, final cut pro on Mac and Adobe Premiere on PC are the way to go, unless you have the budget for Avid, (which I'm guessing, because of the project you haven't). There are several other tools like Sony's Vegas. All the above mentioned products have tools for encoding for various output. Bearing in mind that it is for a web download, there is likely to be compromise on Video quality as much as audio. You will just have to see what your bandwidth limitations are and go with it. Dolby digital is pretty good quality at around 224kbps, however, that might not fly for your web download, I don't know of any tools that video editors have (outside of the ones mentioned above) that will "magically" give you better quality.

Regards


Roland

[Gerax]

I'm trying to do some tests, like encoding with Mpeg2 at maximum bitrate (384Kbps), but still, the sound of the double bass which is very complex in low frequency and high end harmonics (when played with bow as in this case) really isn't the same...
I guess professional video guys use some other tools to do their final encoding to DVD, as other DVD releases I did audio for came out almost fine for what audio was concerned...this lends me to belive that not all Mpeg2 encoding algorithms are created equal...
Sony Vegas Pro is credited as professional tool for AV creation...the fact is I'm missing something or this isn't completely true...

[Roland]

Originally Posted by Gerax

I'm trying to do some tests, like encoding with Mpeg2 at maximum bitrate (384Kbps), but still, the sound of the double bass which is very complex in low frequency and high end harmonics (when played with bow as in this case) really isn't the same...
I guess professional video guys use some other tools to do their final encoding to DVD, as other DVD releases I did audio for came out almost fine for what audio was concerned...this lends me to belive that not all Mpeg2 encoding algorithms are created equal...
Sony Vegas Pro is credited as professional tool for AV creation...the fact is I'm missing something or this isn't completely true...

I used to (well still do own) a high end DVD encoding card. Audio for DVD is encoded as mpeg 1 (crude, not recommended), Dolby Digital AC3 the majority of all DVD releases (good the sound changes slightly, but not in a particularly bad way), and occasionally DTS, some consider slightly higher quality than AC3 (I think this is debateable), but this has the limitation that the bitrate is much higher and therefore potentially limits video bandwidth and (depending on the running time of the video) won't fit on the disc without encoding the video at an unacceptable rate.

AC3 is probably not going to fly with a "for web" video. DVD has a much higher bitrate than most video's broadcast on the web and the video is encoded as Mpeg-2. Nowadays Mp4 is much more common as is VC1, wmv, etc.

Firstly I think you need to talk to whoever is putting the video up and find out what the file format/size and bitrate limitations are then look to one of the tools mentioned above for encoding it.

Regards


Roland

[Gerax]

I did a few more tests and it looks like I can render to a QT7 (.mov) file which looks much better and sound is uncompressed PCM 16/44.1. (now, if only I could find how to make it 4:3 and not 16:9 it would be perfect, as I can't see any option about that in the render menu)
Video codec is still Mpeg4 but with uncompressed audio I belive I can do uploads without too much of an hassle. I'm now checking for filesize...

So far it's the best result I got...

[d_fu]

There is really no need to limit yourself to lossily compressed audio formats - a good DVD authoring program will also support LPCM formats, e.g. 16 or 24 bit, 48 kHz. I've done several DVDs in such formats, including video.
This also does not require QT.

[Roland]

Originally Posted by d_fu

There is really no need to limit yourself to lossily compressed audio formats - a good DVD authoring program will also support LPCM formats, e.g. 16 or 24 bit, 48 kHz. I've done several DVDs in such formats, including video.
This also does not require QT.

The problem is that you can't stream this. Flash is the predominant format at the moment when it comes to web delivery.

Regards


Roland

[kstrauss]

Originally Posted by Gerax

This is not my first audio for video job, but I've always let the final encode to the video guys who supposedly have better tools for this task...
What would you use (on PC) to assemble the finished video and audio so that the sound isn't so smeared and not true to my original recording?
Any particular settings I should be aware of?

I would suggest that you create three resolutions for streaming - this is common practice nowadays, the user can choose whichever resolution works best, or if you're using a more sophisticated server, it can autodetect bandwidth and deliver the best quality stream.

h.264 video and AAC audio can generally deliver quality equivalent to or better than DVD at around 2.5 Mb/sec, and you can cheat the audio to a higher bitrate if you want -- 2.1 Mb/sec video and 320 kb/sec audio delivers pretty decent quality, certainly better audio than AC-3. Adobe Media Encoder will do the trick - choose h.264 as the format, NTSC DV High Quality, then when you edit the preset, set the video and audio bitrate accordingly. Quicktime Pro will also work - probably one of the best deals for video encoding at $25.00, but I think it only runs on a MAC,

Most of the compressions settings should be self explanatory, but I can give you more details if you want.

[kstrauss]

Originally Posted by Roland

The problem is that you can't stream this. Flash is the predominant format at the moment when it comes to web delivery.

For short clips that are a progressive download you can use Quicktime which supports PCM audio. The problem with PCM is that audio and video can get out of sync with Quicktime on a PC. Flash does not support PCM audio.

[Audiop]

Originally Posted by kstrauss

Quicktime Pro will also work - probably one of the best deals for video encoding at $25.00, but I think it only runs on a MAC,

Agree. Another (free) option is MPEG-Streamclip.


/Peter

[Gerax]

Thanx for the input so far.

QT Pro and Mpeg streamclip both work on PC, and as a matter of fact I have them installed.

I'll talk to my client to know what server he's going to upload the clips to.
The fact is, he's also going to upload the full concert (1hr plus) on his website, so I guess I'll be forced to find a compromise as the filesize will be enormous...

I'll look into these settings.

[Gerax]

Looks like Mpeg Streamclip is the way to go

I tried to convert an DV AVI export frovm Vegas Pro with uncompressed audio to H264 and AAC Audio: picture quality remains good and so does audio (at first glance). The downside is that I'll have to render everything to AVI first and then convert to H264...which adds non billable time to this project...

Anyway, thanx, I'll let you know how it goes.

L.G.

[ebulb]

Originally Posted by Gerax

Looks like Mpeg Streamclip is the way to go

I tried to convert an DV AVI export frovm Vegas Pro with uncompressed audio to H264 and AAC Audio: picture quality remains good and so does audio (at first glance). The downside is that I'll have to render everything to AVI first and then convert to H264...which adds non billable time to this project...

Anyway, thanx, I'll let you know how it goes.

L.G.

If you edited in Vegas why cant you render to .MP4 out of vegas ? The mainconcept or Sony options in render ouput are very good.

Audio on DVD is best to leave at PCM for quality (if you arent under any space constraints). If you end up using more than 60min on single layer though you have to compromise.

[Gerax]

I can render to MP4 but it looks like I'm forced to use compressed audio with that format, no possibility to use PCM...

Anyhow, the Streamclip conversion to H264 isn't that long, the rendering tome to .AVI is though...

[ebulb]

Originally Posted by Gerax

I can render to MP4 but it looks like I'm forced to use compressed audio with that format, no possibility to use PCM...

Anyhow, the Streamclip conversion to H264 isn't that long, the rendering tome to .AVI is though...

If you are doing a streaming web upload you wont be able to use PCM for that.. If its going to DVD.. PCM is the go.. If its going online .MP4 is probably the best bet.. .MP4 uses bitrates for audio around the same as MPA or AC3 but the format or the algorithms aren't the same so your results would sound different

[Gerax]

Hello

Bringing back this topic from the abyss to ask another question.

I'm doing some research but it looks like there are few ways to get around the terrible compression that YouTube shrinks my fles with...

I'm uploading some 3min videos on my YT account, and the compressed format I'm putting up is QT in H264 HD (44.1 encoded @320Kbps). The loaded YT file sounds as we all know, harsh and compressed with a severe rolloff over 8KHz, while my original compressed file sounds fine.
Doing some research on the web I found that YT converts everything in Flash format to some quite restricted settings.

In comparision I found a few videos (like this one: YouTube - AKG Perception studio condenser microphones P 120, P 170, P 220, P 420, P 820 - 'I can fly') which though still sounding a bit funny with flanging highs aren't so severely rolled off.

Is there a way to preserve the original quality of my audio material intact as much as possible? Settings? Codecs, Format Converters?

Thanx

L.G.

[Roland]

Originally Posted by Gerax

Hello

Bringing back this topic from the abyss to ask another question.

I'm doing some research but it looks like there are few ways to get around the terrible compression that YouTube shrinks my fles with...

I'm uploading some 3min videos on my YT account, and the compressed format I'm putting up is QT in H264 HD (44.1 encoded @320Kbps). The loaded YT file sounds as we all know, harsh and compressed with a severe rolloff over 8KHz, while my original compressed file sounds fine.
Doing some research on the web I found that YT converts everything in Flash format to some quite restricted settings.

In comparision I found a few videos (like this one: YouTube - AKG Perception studio condenser microphones P 120, P 170, P 220, P 420, P 820 - 'I can fly') which though still sounding a bit funny with flanging highs aren't so severely rolled off.

Is there a way to preserve the original quality of my audio material intact as much as possible? Settings? Codecs, Format Converters?

Thanx

L.G.

I think that I did mention above that most web delivery is Flash, good or bad, that's what we are living with at the moment, though I suspect this will be an evolving situation.

The problem with Youtube is that it's free, quality is never going to be the benchmark. If you upload video's as HD the sound quality is significantly better, if still not amazing, the lower def settings significantly curtail frequency response as you have already mentioned.

Good luck


Roland

[NorseHorse]

Additionally, you can export .mp4 (H264) with 320kbps mp3 audio, which is pretty good. Just make sure you listen at the highest settings on YouTube (not 360p, please)!

For DVD, Premiere defaults to exporting 16-bit PCM.

[Roland]

Originally Posted by NorseHorse

For DVD, Premiere defaults to exporting 16-bit PCM.

But anyone seriously working in DVD encodes in Dolby Digital. The spec originally called for LPCM, but in real terms it was a menace as the data rate was so high it left little room for video encoding, both in terms of bit rate and total running time. DTS had a go into the market, but ultimately, didn't get much market penetration, alongside the fact that the data rates were twice that of Dolby encoding. I know some people will argue that the spec alows for maximum data rates of around 10.06 mbps (if my memory serves me correctly), but there are several reasons why you don't want to be operating anywhere close to that limit, not least that discs with high data rates tend to fall over and glitch more on playback.

Regards


Roland

[Audiop]

You may want to check out Vimeo for showing your videos. There is one free and one pay for membership.

I use H.264 MP4 with AAC for the web and AC3 for DVD. Sure, as audio nuts we want optimum sound quality but as already mentioned, video quality may suffer to much.


/Peter

[matthewd]

I didn't catch what the overall length of the project was but if not all that long you could probably use linear PCM ie 48k wav file (btw make sure if you are doing any sample rate conversion that you are doing it at high quality - some sample rate converters have quick and dirty settings or high quality settings). You can do a bit budget - there are plenty online, whereby you enter the number of mins and the mbps of the video and you can easily see if it needs to be AC3 (Dolby Digital) or linear PCM. What some people do if they want to get the 5.1 logo on the packaging is put the stereo mix through some kind of stereo to 5.1 unwrap - TC Electronic do a pretty good one. You can then put the Dolby Digital on as a 5.1 as say the default track and linear PCM as audio track 2 that the connoisseur can select at will. All subject to space. I always thing it is a bit bizarre to have Dolby Digital 2.0 because everyone thinks of Dolby as surround.

Matt

[NorseHorse]

Originally Posted by Roland

But anyone seriously working in DVD encodes in Dolby Digital.

Interestingly enough, I just noticed the the default audio setting for an Adobe Encore project (DVD authoring) is Dobly Digital.

But is there any reason not to write in PCM if you've got the space?