@AAProds @johnebaker

Hi Alwyn.

You say you 'import' the file into MEP.

Does the same happen if you copy the file into the project instead?

I'm trying to decide if MEP handles files differently depending on how they are imported.

I think John CB in the past has complained about not being able to right click and use the external audio editor when importing files. Maybe it's part of the same problem?

Ray.

@johnebaker John,

...which audio format/codec/sample rate are your recording as?

Audio
ID                                       : 1
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : 1
Duration                                 : 3 h 15 min
Bit rate mode                            : Constant
Bit rate                                 : 3 072 kb/s
Channel(s)                               : 2 channels
Sampling rate                            : 96.0 kHz
Bit depth                                : 16 bits
Stream size                              : 4.18 GiB (5%)
Alignment                                : Aligned on interleaves
Interleave, duration                     : 40  ms (1.00 video frame)
Interleave, preload duration             : 500  ms

is there a reason for not using MEP to capture VHS, saving directly as MXV file?

MXV limits my options for working with the material in the future. Who knows what will happen re MEP... It also allows me to losslessly chop up/join captures with Direct Stream Copy in VDub.

@CubeAce Ray, I'm dragging them in from the media pool.

Hi Alwyn.

MEP may not like the 96kHz Sampling rate. Try using 48kHz.

Ray.

@AAProds

Hi Alwyn

Thanks for the MediaInfo analysis - this looks to be the same as an issue in January another user had.

The AVI video is a type 2 AVI file - the audio stream is a separate stream from the video which MEP does not handle properly - it needs converting to a Type 1 AVI - where the audio is muxed into the video stream - this can be done easily using DVDate

HTH

John EB

@AAProds

Hi Alwyn.

"@CubeAce Ray, I'm dragging them in from the media pool."

Do you no longer get the option box when dragging files?

Ray.

Hi

The only other thing I notice is that the data rate of the PCM file is 3072kbps - double the usual rate rate of 1536kbps. I ask the audio gurus here - is that to be expected when the sample rate is doubled at 96khz instead of 48khz ?

Peter

@AAProds @Scenestealer @johnebaker

Hi Peter.

Now here's a thing. I've just made some PCM audio files at various bit depths and sample rates and only imported them into MEP (not copying). Not only did all of them play OK but showed waveforms on import and I could get the 'Edit in external audio editor' to appear.

My only conclusion is John EB is correct and that somehow the container files isn't being read correctly.

But why does a PCM file on it's own be able to be edited in the external editor when importing only and yet in a video file the sound track can't? Is it because the video original can't be altered (NLE) and the external audio editor could do just that?

Ray.

@CubeAce

But why does a PCM file on it's own be able to be edited in the external editor when importing only and yet in a video file the sound track can't? Is it because the video original can't be altered (NLE) and the external audio editor could do just that?

I think this is answered in the my recent posts in the VPX12 thread. MEP/VPX creates/converts a video files audio to an .hdp file on import - I think this is to allow the audio to be edited separately in the timelime, although .hdp is native to Magix Audio Editor and Samplitude etc., so it does not explain why it can not be edited directly in those program without converting back to a wave file...??

Peter

@johnebaker @CubeAce @Scenestealer

Thanks all for your inputs. As soon as I posted that Mediainfo analysis, I thought "hang on, that 96k audio doesn't sound right". So I did a recapture overnight with Virtual Dub but did it at 48khz (previously, I didn't even know that you could choose the KHz!) and it came onto the timeline with no issues, creating the waveform automatically. So it seems that it was indeed the 96khz that has thrown MEP (but only with long files, it appears).

John, I remember DVDate! Very handy in the early days of MEP to convert DV-AVIs so MEP would like them. As mentioned though, my AVIs are Lagarith and DVDate tried to convert them to DV.

Ray, I don't normally use the import arrow; I just usually drag and drop. But I tried it and the result was the same.

Peter, you'll be pleased to know that at 48KHz, my 3 hour tape went from 82gb to 69gb. A bonus 13gb! 👍

I'm now using VDub to recompress the audio to 48Khz (and Direct Stream Copy the video).

Cheers, Al

@Scenestealer @AAProds @johnebaker

Hi Peter.

An hdp. file is a Microsoft graphics file. (HD Photo.) It doesn't in itself contain any audio so there is no audio to edit within the file. So, wouldn't the program still be dealing with the original file at it's location. Being non destructive editing, that would go against the principle of the program. Without using a copy that can be altered surely MEP has nothing to work with.

[Further Edit] So far I have not found one hdp. file that is more than 2.97KBs in size regardless of the file it represents so I feel it can barely be more than an instruction set rather than a file format containing pertinent data.

Hi Alwyn.

Whether you drag and drop as I did in my example or use the download button should make no difference. I always drag and drop and always have the option. You must have ticked the 'do not show me again' option at some point. So I still don't know whether you import a file into the program or copy it.

Still I'm glad you got it back.

Ray.

@AAProds @Scenestealer @johnebaker

Guess what happens if you try to open an HDP file by directly double clicking on it?

Ray.

@johnebaker @Scenestealer @CubeAce

A related question: Virtual Dub gives me a 8 or 16 bit audio option. What would be the best for MEP? Is the "bit' value only related to bandwidth/file size (and therefore, I assume, quality)? In this example, the 8bit option is 94KB/sec, whereas the 16bit option is, as shown, 188KB/sec

.

@AAProds

Hi Alwyn

. . . .Virtual Dub gives me a 8 or 16 bit audio option . . . .

IMHO CD quality is the minimum quality I would aim for - ie 16 bit depth. Bit depth refers to the number of bits used to describe 1 sample of for example a 48kHz sample rate audio.

The overall effect on the audio stream size using a higher bit depth and sample rate - within reasonable limits - is small compared to the size of the video stream.

John EB

@AAProds

Hi Alwyn.

The audio bit depth is effectively the amplitude headroom in simplest terms . The amount of digital steps between no sound and clipping. Depending on the quality of the original audio you may well hear a difference between 8 bit and 16 bit.

I never use or produce files of below 16 bit personally and with my own created audio stick to 24 or 32 bit float, but that is for music and not speech. Combine that with the sampling rate that helps with things like placement within a stereo image and ambience, both interact to give more accurate information between channels and smoother waveforms.

Ray.

@AAProds

Hi Alwyn

@CubeAce has described bit depth more accurately - I blame lack of coffee first thing in the morning.

John EB

@AAProds @johnebaker @CubeAce

Ray (CubeAce) wrote:

you may well hear a difference between 8 bit and 16 bit.

I would say, most definitely you will! Especially if the audio contains a wide range of frequencies (e.g. music) and a "large" dynamic range. Like Ray, I would never consider using anything less than 16 bit.

Jeff

@johnebaker @emmrecs @Scenestealer @CubeAce Thanks guys. I will stick with 16bit.

John, coffee for you, glass of red for me (sun's just about to go down here!).

@Scenestealer @AAProds @emmrecs @johnebaker

There are people who will say that 16 bit 44kHz should be enough based on Harry Nyquist's work into digital audio and the main reason for the implementation of the specifications for compact disc. I personally am not sure from a video angle that has a set sampling rate of 48kHz. Certainly some of the ogg vorbis files supplied within MEP are of a higher standard than the majority of my compact discs for audio clarity. The other problem is the final encoding to standard video formats with downsampling, but as a rule of thumb I think that when audio is downsampled there is a risk of creating third harmonic distortions that while can't be heard as distortion can upset the ambience of a recording. But I'm probably going too far down the rabbit hole now and most people will not be monitoring to that degree or able to hear differences due to equipment limitations. My own hearing while good for my age, is not what it once was and I don't pretend to hear the higher frequencies I once could.

I am on my third cup of tea 😉.

@CubeAce

Hi Ray

The reason for using 48kHz audio is due to the minimum sample rate of the Blu-Ray standard required for LPCM*, AC-3, Enhanced AC3 and DTS Digital Surround and 4 other supported audio formats that are not available to consumers.

* LCPM can also be 96 or 192 kHz sample rate.

Bit depth depends on the audio format, 16 being the minimum for all audio formats, other values are 20 and 24 bit however not every format supports these.

DVD minimum sample rate is 44.1 kHz with 48, 88.2 and 96 kHz being supported for all audio formats from mono to 5.1 Surround Sound. Bit depth support is 16, 20 or 24 bits.

HTH

John EB