Audio encoding with CinemaCraft (CCE)

[vcddude]

Hi,

I see lots of posts saying that CCE does not do a good job with audio. Does this apply
to both MPA and WAV encoding? Is the issue audio quality or audio/video sync, or both?

If I encode an AVI with CCE to MPEG2 with elemental streams (MPV and WAV), will
the resulting WAV file be suitable for conversion to AC3? and will it be "correct" and in sync
with the video?

I prefer CCE's speed and just want to know if it's WAV creation can be used reliably.

Thanks,
Kevin

[redwudz]

Some members have said the same thing about TMPGEnc's quality of audio. I just save out the audio as a WAV and use the encoder for just the video. I use VirtualDub Mod, save out the WAV and convert to AC3 with ffmpeggui, then add it back in when authoring.

Then I frameserve the just the video to TMPGEnc encoder directly. You may try something similar with CCE. It eliminates a few steps in the conversion process. If you use a authoring program that accepts elemental streams like TDA, it's easy to add the audio in during the authoring process. If not, you would have to mux the audio and video together before authoring.

Usually, though, you shouldn't have any sync problems using a WAV file, even from CCE. You are probably aware of MP3 VBR audio and the sync problems it can cause. That's one reason I use the WAV format fairly often when re-encoding Xvids to MPEG-2.

[vcddude]

OK thanks -- so it sounds like I'm better off using Virtualdub to extract the WAV from the AVI and converting that to AC3, and converting just the video with CCE.

Makes sense.

Thanks,
Kevin

[jman98]

There are 2 things at work here.
1) CCE 2.50 has a problem where if you have an AMD CPU and you try to encode audio with CCE, it will crash the box. This was the start of the "don't use CCE for encoding audio" posts in the past.
2) Honestly, while both CCE and TEMPGenc can encode audio, there is a decent argument that maybe you shouldn't use them to do so. Other applications are considered to do a better job.

I love CCE, but I never ever use to encode audio.

[Cornucopia]

...and TMPGEnc works great when you use LAME as it's encoding plugin (much better than by itself).

As usual, it's best to use the correct individual tool for a particular job, not just a "Swiss Army Knife".

Scott

[vcddude]

OK, so I am trying to get a solid answer to my original question:

While I can indeed use VirtualDub to strip out the WAV from the DV AVI,
I'd like to streamline the process and eliminate this step if possible.

Can I skip this step and instead configure CCE to output the WAV file
along with the MPV? Are there any issues with CCE-generated WAV files?

Is a CCE-generated WAV file identical to that produced by VirtualDub?

Thanks again,
Kevin

[bobkart]

WAV files are uncompressed, so there should be no issues of encoding quality when generating one. So only a decoding issue would create "bad" WAV files from whatever is being decoded (uncompressed). I'm not 100% sure but I don't think that's a possibility short of a broken codec.

[bobkart]

Is a CCE-generated WAV file identical to that produced by VirtualDub?

You might be able to determine this experimentally. Granted, testing a few examples doesn't prove it for all cases. As I said though I expect the answer is yes.

I can compare two WAV files (assuming 16-bit stereo) and tell if they are identical or not (and by how much they differ, it's really just a subtraction, which gives zero if they are identical). If you want to compare two WAV files like this and are not able to find that capability in some off-the-shelf application, I may be able to help.

[FulciLives]

I know with TMPGEnc Plus that if your input video file has standard PCM WAV audio (i.e., 2 channel 16-bit 48k) and you select the LPCM WAV option in TMPGEnc Plus that all it does it pass along the WAV file from the original i.e., does a demux if you will.

Since DV AVI is 2 channel 16-bit 48k PCM WAV then I know TMPGEnc Plus will just pass it through i.e., demux it.

One would assume (hehehe) that CCE would do the same BUT eventhough I have obviously tried this with TMPGEnc Plus I have never tried it with CCE so ... I guess you will have to try it and find out!

- John "FulciLives" Coleman

[vcddude]

OK, interestingly enough, I found that the WAV files produced by CCE and VirtualDub are indeed NOT the same.

I used a 1min 1sec DV AVI clip and extracted the WAV using both tools. Here is what I found using Sound Forge to analyze: (both are 48K stereo PCM)

DV AVI:
- Length is 01:01.061 (2,930,928)

CCE-produced WAV:
- Length is 01:01.098 (2,932,736)
- Size is 11457KB

VirtualDub-produced WAV:
- Length is 01:01.061 (2,930,928)
- Size is 11449KB

This tells me that, indeed, VirtualDub WAV extraction provides the correct WAV file and CCE should not be used for WAV file extraction. CCE apparently produces WAV files whose lengths do not match the length of the source AVI. Virtualdub produces the correct WAV file.

Using VirtualDub adds an extra step, but based on this result, it is THE way to go.

Thanks,
Kevin

[redwudz]

If you were to use VirtualDub to frameserve the DV video directly to CCE, that would simplify the process. https://www.videohelp.com/virtualdubframeserve.htm

[vcddude]

If you were to use VirtualDub to frameserve the DV video directly to CCE, that would simplify the process. https://www.videohelp.com/virtualdubframeserve.htm

How so? Doing that does not negate the need to extract the WAV from the DV AVI using VirtualDub for later encoding to AC3.

Thanks,
Kevin

[vcddude]

Out of curiosity I ran the same test also with TMPGenc and Procoder Express. I am surprised to find additional variability in the WAV file sizes. Here is the cumulative summary:

DV AVI:
- Length is 01:01.061 (2,930,928)

CCE-produced WAV:
- Length is 01:01.098 (2,932,736)
- Size is 11457KB

VirtualDub-produced WAV:
- Length is 01:01.061 (2,930,928)
- Size is 11449KB

TMPGenc-produced WAV:
- Length is 01:01.061 (2,930,960)
- Size is 11450KB

PCE-produced WAV:
- Length is 01:01.027 (2,929,326)
- Size is 11443KB

Interesting to see that only VirtualDub produces a WAV file whose duration exactly matches the duration of the source AVI. TMPGEnc comes in close, but not quite exactly...

Kevin

[vcddude]

Another update:

The previous test used CCE 2.5 SP.

When I ran the test with CCE 2.7 Basic, the WAV file was correct!

CCE 2.7 Bssic produced WAV:
- Length is 01:01.061 (2,930,928)
- Size is 11449KB

So, looks like CinemaCraft fixed the problem and CCE 2.7 Basic can be used to be
create correct WAV files!

Kevin

[FulciLives]

When I used TMPGEnc Plus in the past to "pass through" the PCM WAV audio I used the LAME plug-in which always processes the audio first and it would happen very quickly.

I wonder if your figures for TMGPEnc Plus were based on using the LAME plug-in or did you just use the built-in TMPGEnc Plus audio settings?

- John "FulciLives" Coleman

[vcddude]

When I used TMPGEnc Plus in the past to "pass through" the PCM WAV audio I used the LAME plug-in which always processes the audio first and it would happen very quickly.

I wonder if your figures for TMGPEnc Plus were based on using the LAME plug-in or did you just use the built-in TMPGEnc Plus audio settings?

- John "FulciLives" Coleman

Good point. Actually I used TMPGEnc's internal audio encoder, not the LAME plugin.

Kevin

[FulciLives]

When I used TMPGEnc Plus in the past to "pass through" the PCM WAV audio I used the LAME plug-in which always processes the audio first and it would happen very quickly.

I wonder if your figures for TMGPEnc Plus were based on using the LAME plug-in or did you just use the built-in TMPGEnc Plus audio settings?

- John "FulciLives" Coleman

Good point. Actually I used TMPGEnc's internal audio encoder, not the LAME plugin.

Kevin

Well I always figured TMPGEnc Plus was just passing the audio through because when you use LAME, as I said, the audio gets processed first and it can take some time but when my input was already 2 channel 16-bit 48k PCM WAV the process would happen in just a few seconds or so which I why I always thought it just got passed through or dumxed without any fanfare.

That's why what you said sounded somehow not "right" to me.

That's when I wondered if you used LAME or not.

Try LAME and see how it goes. I know you don't use TMPGEnc Plus but it would be nice to "set the record straight" for others reading this.

- John "FulciLives" Coleman

[vcddude]

When I used TMPGEnc Plus in the past to "pass through" the PCM WAV audio I used the LAME plug-in which always processes the audio first and it would happen very quickly.

I wonder if your figures for TMGPEnc Plus were based on using the LAME plug-in or did you just use the built-in TMPGEnc Plus audio settings?

- John "FulciLives" Coleman

Good point. Actually I used TMPGEnc's internal audio encoder, not the LAME plugin.

Kevin

Well I always figured TMPGEnc Plus was just passing the audio through because when you use LAME, as I said, the audio gets processed first and it can take some time but when my input was already 2 channel 16-bit 48k PCM WAV the process would happen in just a few seconds or so which I why I always thought it just got passed through or dumxed without any fanfare.

That's why what you said sounded somehow not "right" to me.

That's when I wondered if you used LAME or not.

Try LAME and see how it goes. I know you don't use TMPGEnc Plus but it would be nice to "set the record straight" for others reading this.

- John "FulciLives" Coleman

No problemo -- I'll get to this over the weekend for completeness.

Kevin

[vcddude]

OK, I ran additional tests with TMPGEnc using both LAME 3.90 and SCMPX 1.51 as the audio encoding engine:

DV AVI:
- Length is 01:01.061 (2,930,928)

LAME 3.90-produced WAV:
- Length is 01:01.061 (2,930,960)
- Size is 11450KB

SCMPX 1.51 -produced WAV:
- Length is 01:01.061 (2,930,960)
- Size is 11450KB

So, neither LAME nor SCMPX produced WAV files whose length exactly matched the length of the source DVI.

Bottom line: Only VirtualDub and CCE-Basic 2.70 produce exact-length WAV files that match the length of the source DV AVI (in terms of the time and # of audio samples).

I find this very surprising.

Thanks,
Kevin

[FulciLives]

I have to admit that your results are rather odd. No I am no challenging your results just that they seem surprising.

All I know is that in the past when I used TMPGEnc Plus for video and audio (with the audio already being 2 channel 16-bit 48k PCM WAV format) I never had a problem wih A/V sync.

So the difference seems to be so small that it probably really makes no difference.

- John "FulciLives" Coleman

[bobkart]

The 32-sample difference he is seeing at 48KHz comes to 2/3 of a millisecond.

[vcddude]

I agree the results are odd, and the variation is so miniscule that it likely doesn't make
any difference. I just find it strange that these tools don't put out an exactly matched WAV file.
Note that I've never had an issue with A/V sync using TMPGEnc and Procoder Express either.

Kevin

[bobkart]

It might be interesting to know from which end the missing 32 samples were lost, or if both ends were affected.

I suspect it might have something to do with rounding when determining the length of the video involved, based on non-integral framerates like 23.976.

[vcddude]

I agree, I will take a closer look at the WAV files using Sound Forge or Vegas to see where
the discrepancy lies (e.g. at the beginning or end of the file). Yes I was using a
non-integral framerate of 29.97 fps (I am in NTSC-land).

Stay tuned,
Kevin

[vcddude]

Sorry for the delay, but I compared the sound files using Vegas and found that, in all cases, the discrepancies came at the end of the files. Depending on the encoder, samples were either deleted from the end or extra garbage was added at the end.

Given the discrepancies are so small, I don't think this is a big deal, although I still
find it interesting and puzzling.

Kevin

[SaSi]

Although every different Mpeg encoder will produce different results in term of quality, differences in video encoding can be much bigger than audio.

AC3 audio is considered as of higher quality compared to MPEG for the same bitrate. This can be a reason for chosing an AC3 encoder in favour of the CCE or Tmpgenc encoders for MPEG.

However, especially when re-encoding xVid or DivX video files, where the "original" audio can be 128kbps VBR, I believe there is "little left" in terms of quality to justify the thoughts.

I personally have never had the opportunity or the reason to encode high quality stereo audio to worry about loss of quality, so I always "trust" CCE or Mainconcept to encode the audio at 192kbps. Perhaps there is a small loss compared to other, first class encoders, however I swear it is not audible to me.