Audio Bit Rate

Xenofex2 wrote on 3/20/2019, 11:14 AM

Whilst I have found a way around my latest issue, again concerning missing audio, I am though wondering why and if there is a more simpler route to resolution.

Following on from my ‘No Audio in last Section’ posting on the Forum, I have gone back to the drawing board and so re-editing. Original small video clips taken a few years ago that requires Quicktime, have been
converted using ‘Handbrake’. (Originally I had used Movavi Video Converter).

All clips are 640 x 480 and are 30fps. (Checked with MediaInfo and all are constant frame rate.) After conversion, play using VLC and I have audio. Import them into MEP however to edit and there is no audio.

Reading other postings on this Forum I did note one mention a program called Video Enhancer. Wondering whether MEP then had an issue because of the small pixel size of the video, I thought I would give this program a try. (Actually not sure whether this is a Free or Paid For program.) With Handbrake and Video Enhancer I have just left the Settings on default as have no idea as to what should, if anything, be changed.

Regardless, after being run through Video Enhancer, the clip still has audio when played in VLC, but more importantly, now has audio when importing into MEP. The clips though have remained exactly the same size.

The answer I think lies in, right click, Properties, Details of each Movie Clip. Before I started anything, Audio Bit Rate is 68kbps and Channels 1. After the conversion in Handbrake, Audio shows Bit Rate as 38kbps. Channels 1. The same information after Handbrake and then using Video Enhancer, the Bit Rate is now 276kbps and Channels 2. So maybe I do need both programs in this instance?

What though it all means I would appreciate some guidance please.

George

PS - Interestingly, I have just found out that this last conversion in Video Enhancer, whilst giving me audio, has changed the frame rate to variable which was what I was trying to avoid.

Comments

johnebaker wrote on 3/20/2019, 12:58 PM

@Xenofex2

Hi George

. . . . converted using ‘Handbrake. . . .All clips are 640 x 480 and are 30fps.. . . . After conversion, play using VLC and I have audio. Import them into MEP however to edit and there is no audio. . . . .

What does MediaInfo say the audio is?

Ideally the audio should be 48 kHz samplerate and 96 or 128 kbs bitrate.

John EB

Xenofex2 wrote on 3/20/2019, 1:02 PM

Just a further comment as I seem to complete full circle but seem to be disappearing down into a giant vortex.

In my initial editing attempt about ten days ago with about six clips, I had first used Movavi Video Converter 19, and the final outcome in MEP after exporting, and which I subsequently found out, was a stretched video.

So now taking a closer interest in frame rate, for a further attempt I went back to the drawing board and again used my Movavi program. Plays ok in both VLC and MEP. Dragging the clip into MediaInfo, it tells me the frame rate is 30.00. Via Properties in the actual clip and it tells me it is 30.13. Start a new project in MEP and drag the clip into the program, MEP tells
me it is 29.97.

All I wanted to do was edit some family movie clips taken on a digital compact a few years ago.

Not sure where I am now. One conversion with Handbrake and there is no audio within MEP. Second one now putting it through Video Enhancer changes the clip to a variable frame rate but gives me audio. Third attempt with Movavi program and the frame rate information varies depending where I look.

George

Xenofex2 wrote on 3/20/2019, 2:17 PM

John,

Regarding the Handbrake conversion, MediaInfo tells me under Audio that the Sampling Rate is 8.000Hz and the Bit Rate is 41.1kb/s.

Just out of interest, the Movavi conversion, of which I do not have an issue with the audio but instead possibly with the video frame rate, MediaInfo tells me that the Bit Rate is 96.0kb/s and the Sampling Rate 44.1.

George

Xenofex2 wrote on 3/21/2019, 7:52 AM

I have just completed a test using just one small clip. It needs QuickTime so I need to convert.

1) Saw Video Enhancer mentioned in a posting, so in the first Test, I used this, and then ran the result through Handbrake. Here all Audio was lost. The first part, via Video Enhancer, according to MediaInfo showed a variable frame rate that I know MEP will not support, so this was the reason I then tried Handbrake. It changed the frame rate to constant, but still no audio.

2) In my second test, I used Handbrake to convert. According to MediaInfo it gave me a constant frame rate, but playing in VLC and there was audio, import into a new project in MEP and there is no audio. I did alter (I think) the Bit Rate in MEP to match the MediaInfo, 41,100 but this made no difference.

3) In my third test I went back to Movavi Video Converter 19, the program I now normally use. (It was first using this to convert in which on export, MEP stretched the video. Support told me the reason being the frame rate was 29-9707 and variable.) With audio there was no problem, however the oddity here is the frame rate. Properties tell me it is 30.13fps. MediaInfo tells me it is 30fps and constant. However open a new project in MEP, and MEP tells me the frame rate is 29.97.

I guess the answer is to use Movavi, check in MediaInfo that all Clips being used are definitely constant frame rate, and then do regular exports as I edit just to make sure that the video is not again stretched.

George

johnebaker wrote on 3/21/2019, 10:11 AM

@Xenofex2

Hi George

. . . . Handbrake conversion, MediaInfo tells me under Audio that the Sampling Rate is 8.000Hz and the Bit Rate is 41.1kb/s . . . .

The audio data is very poor audio quality, a low sampling rate and bitrate even for listening - it is about telephone quality.

Acceptable sampling rates are 44.1 kHz (CD quality) and 48 kHz (recommended (hi fi quality?) and 96 kpbs and higher.

With MovAvi you can customise a standard preset, specifying the video bitrate, quality, level etc,and audio samplerate and bitrates etc, and save as a preset.

HTH

John EB

Xenofex2 wrote on 3/21/2019, 12:17 PM

John

Again, thankyou. I keep re-reading your answer and absorbing the information as I begin my Audio Learning Curve.

An interesting journey, as instead of scribbling information on bits of paper as I normally do, I am glad that this time I recorded all the details (I think) on an Excel page. As a result, I see that this movie clip started out exactly as you described. ‘poor audio quality’, but it is only as a
result of the Movavi conversion that the Bit Rate and Sample Rate have improved to what you highlight is an ‘acceptable level’.

Although the Forum Header is ‘Audio Bit Rate’, may I just highlight the other oddity I noticed? My initial question here had come about after my attempt to edit six clips had resulted on export in stretched video with Support subsequently advising me that the frame rate was 29.9707.

After the latest Movavi conversion, properties told me the frame rate was 30.13, whereas MediaInfo had it as 30fps and constant, yet starting a new project in MEP, this asks me if I wish to adjust the project to this imported clip, which they say is 29.97 – three different fps for the same clip.Presumably just adjust the Project and then, in light of previous problems, do
regular exports to MPEG4 as I edit so I can monitor as I progress and see at an early stage if the video again stretches?

Again thankyou John. And to mis-quote an old Paul Simon song, ‘Still Learning After All These Years’.

George