Windows application to extract sample?

[yetanotherlogin]

Hello

I'm having an issue with ffmpeg, so need to find a Windows application simply to extract a sample from an MPEG movie shot with a camcorder. FWIW, I combined the 2GB files into one using "copy /b *.mpg output.mpg".

Here's what the file looks like per MediaInfo:

Format                                   : MPEG-PS
File size                                : 8.42 GiB
Duration                                 : 2h 8mn
Overall bit rate mode                    : Variable
Overall bit rate                         : 9 404 Kbps

Video
ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2

Audio
ID                                       : 189 (0xBD)-128 (0x80)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Bit rate mode                            : Constant
Bit rate                                 : 448 Kbps
Channel(s)                               : 6 channels
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits

There are so many tools listed that I don't know which to pick: Could you recommend an application for newbies simply to extract a sample without applying any conversion?

Thank you.

[fvisagie]

The one I normally use for tasks like this is Avidemux.

Use the Edit menu to specify the parts you want to cut out. Optional: watch the Frame Type indicator at the bottom and try to set the boundaries on Frame Type I to ensure your cuts happen exactly there and there won't be any issues playing the start or end of the remaining clip.

To save the clip, set Video:Copy, Audio:Copy and Format:AVI and File > Save > Save Video.

[Baldrick]

I had a very simple sample cutter once but can't remember it....


But you could use mpg2cut2, open the mpg, drag the slider and click on the [ to set the start and then ] to set the end. Last file->Save this clip.

[yetanotherlogin]

Thanks for the links. I'll use AviDemux because I find mpg2cut2's interface horrible

BTW, when trying to extract a sample with VirtualDub, would someone know why VirtualDub won't let me select MP3 as audio codec, and complain with "Error initializing audio stream compression: The audio codec cannot compress the source audio to the desired format." when trying AC3 ACM Codec?

Thank you.

[yetanotherlogin]

Also, what's a good Windows application to join those multiple MPEG-PS mpeg2 files? I googled for it, but didn't find much.

[Baldrick]

Mpg2cut2 interface is horrible...but you only have to use two buttons [ ] and save clip....so it's not that difficult and is a very good mpeg2 editor.

You can also join with mpg2cut2, and you don't have to use any buttons, just use file->open, hold in ctrl to select all your files, then file->save all clips.

Or join with vobmerge, file->open, select all files instead of vob files, add your files and last save as a new .MPG. It uses the copy /b command.

[yetanotherlogin]

I read the readme + site, but don't know how to extract the sample that I marked with [ and ]: Is it File > Save Parts, File > Save this clip, File > Save Selection List, or something else? There's no status bar to provide a hint.

To join: What if the files aren't numbered? How will it know in which order to join the files?

[Baldrick]

Reread what I wrote....Last file->Save this clip.

You could join one mpg at time with open and the add file if they aren't numbered. Last File->Save all Clips.

Or use a mpeg2 editor with more a friendly gui like Videoredo. Not free though.

[yetanotherlogin]

Thanks, it worked. I'll join the files, filter them in AviDemux, and see what I get.

[Baldrick]

You can also join in avidemux, open first mpg, then select append for the rest.

[yetanotherlogin]

I tried with AviDemux (2.6 r8295 beta, because I assumed it would have more features than the older, stable 2.5), but no go:
- AAC Faac = no sound in output file
- AAC Lave = sounds "bubbly" even at 192 bitrate.
- MP3 ABR/192 = "Cannot setup audio encoder, make sure your stream is compatible with audio encoder (number of channels, bitrate, format)"

All this with video = Mpeg4 AVC x264 + container MP4 Muxer.

VirtualDub works better, but as I was told that I could slim down the audio by converting the 5.1 into plain stereo, I chose Audio > Compress, but can't select MP3 as codec as the right-side remains empty.

Provided it is indeed a good idea to convert the audio track... do I need to first extract the original audio track (original : A52 AC3 3F2R/LFE 48KHz Bitrate 448 kb/s) into something smaller before importing it in VirtualDub, and if yes, should I use Audacity for this? Alternatively, can AviDemux perform this conversion?

Thank you.

---------
Edit: VD has Audio > Conversion. I'll try Sampling rate = 44.1KHz + Channels = Stereo

---------
Edit : not good enough, as sound is not compressed, just simplified.

-------
Edit: Tried Compression = MP3 56Kbps 22050Hz stereo, but I get the impression audio/video is very slightly out of sync

[fvisagie]

If you only wanted a cut from the MPEG file, consider leaving the audio as is instead of transcoding it.

BTW: the "bubbling" is a signal processing artifact that occurs when transcoding (recoding) audio to another and unsuitable sampling frequency. If you want to preserve all quality from a sampling frequency perspective, preferably transcode to twice the current sampling frequency. In normal use it's sufficient to transcode to the same sampling frequency, even if for a different format. Anything else than these two cases is usually going to cause problems.

[Wolfen]

Might be stupid question but do you have the latest mp3 codec installed ? LAME MP3

[yetanotherlogin]

Thanks for the info. Since 5.1 is useless and I'm saving space by reducing the size of the video stream, is there a way to slim down the audio stream as well without transcoding?

I see that VD has Compression > AC-3 ACM:
Codec : 32-640 kBps 44100Hz Stereo
Extensible : 44100Hz 16 Bit Stereo - 640Kbps 44100Hz Stereo

[yetanotherlogin]

Might be stupid question but do you have the latest mp3 codec installed ? LAME MP3

I used the default files from VD. I'll check which version if comes with and how to upgrade if necessary.

[Wolfen]

VD doesn't come with the Lame mp3 codec you have to install separate.

[yetanotherlogin]

Thanks, I'll find how to do this.

For some reason, the MP3 right-side screen now lists options, while it was empty before. Go figure.

A test shows that a 2mn sample in XVid and MP3 (56kbps 22050Hz Stereo) is down to 3MB, hence the original 2h 9GB file would be down to about... 180MB. Sounds very good

[Wolfen]

that's good but it doesn't hurt to have the latest version of Lame installed

EDIT : LAME is a MP3 encoder and the Lame ACM MP3 is an ACM codec that you can use in most applications for example in Virtualdub(to install the ACM codec just extract all files and right click on the LameACM.inf and select Install). you don't install it through VD, just install from the folder where it was D/L to.

[yetanotherlogin]

I couldn't find an option in VD, so I assume it relies on Lame being installed in the host and the OS to locate it?

http://granjow.net/virtualdub-tutorial-installing.html

[yetanotherlogin]

Checked User and System PATH, along with the Registry, and no trace of LAME (installed in "c:\Program Files\Lame.3.98.2"). I wonder how VD finds it

[aedipuss]

I had a very simple sample cutter once but can't remember it....


But you could use mpg2cut2, open the mpg, drag the slider and click on the [ to set the start and then ] to set the end. Last file->Save this clip.

was it chrissyboy's "makesample"? it works on most formats. he gave permission to have it listed in the tools section but it was never placed there that i know of.

[Baldrick]

I had a very simple sample cutter once but can't remember it....


But you could use mpg2cut2, open the mpg, drag the slider and click on the [ to set the start and then ] to set the end. Last file->Save this clip.

was it chrissyboy's "makesample"? it works on most formats. he gave permission to have it listed in the tools section but it was never placed there that i know of.

Yup, it was it. It makes a sample from the start to the desired file size. I have just forgot to add it to the tools list.

edit: MakeSample mirror: https://www.videohelp.com/tools/MakeSample

[yetanotherlogin]

Thanks for the link.