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  1. Member
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    Hi forum, I just had some questions about audio and fps.

    Question 1
    My encoder of choice is CCE. The knowledgable folks on this forum taught me how to use CCE, AviSynth and DGPulldown to convert non-standard framerate video to NTSC compliant DVD files.

    When I was taught this, I was still encoding both the audio and video in CCE. However, the same people here told me that I should always disable the audio in CCE, as it is a video encoder and let an audio program handle the audio. This was great advice because CCE rarely crashes now that I do that.

    Say I have a video with these specs:
    Video fps = 20.00

    If I use CCE and Avisynth (script is at the end of this post) to convert the video to NTSC compliant, can I use a program like FFMPeg (my audio encoder of choice) or some other command line utility to convert the audio to the same frame rate?

    Below is the script someone from here gave me a while back to use for non-standard fps:
    <SCRIPT>
    AVISource("C:\mymovie.avi")
    LanczosResize(640,336,0,3,592,454)
    AddBorders(40,72,40,72)
    ChangeFPS(59.94)
    SeparateFields()
    SelectEvery(4, 0, 3)
    Weave()
    ConvertToYUY2()
    </SCRIPT>

    Question 2
    I have an AVI file that is 59.94 fps. Would I still have to use the methods discussed above, or is 59.94 NTSC compliant. I know 59.94 is a special fps, I just don't know its actually meaning.
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  2. Mod Neophyte Super Moderator redwudz's Avatar
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    Audio doesn't have a framerate, just length to determine it's playback time. Check the length of your converted video file and your audio file. If they match, then you just need a format for the audio. If they differ, you can stretch or compress the audio length with a audio editor like Audacity to change it. If the change isn't too much, you may not have to adjust the pitch, but Audacity can do that also.

    Someone else may be able to give you help with your 59.94fps video. But what format is it in? What codec is it using?
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  3. Member
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    Hi.

    59.94/2 = 29.97.
    Sure to be NTSC

    Open it in http://mediainfo.sourceforge.net/en. Change to View/Text. Cut and past the text in a post.
    Glad to have a look at it.
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  4. Member
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    Originally Posted by pcspeak
    Hi.

    59.94/2 = 29.97.
    Sure to be NTSC

    Open it in http://mediainfo.sourceforge.net/en. Change to View/Text. Cut and past the text in a post.
    Glad to have a look at it.
    I decided to go ahead and encode the audio and video together in CCE and be done with it . However, I am going to post the information because I would really be in trouble if the files were MP4s as CCE has alot of trouble handling audio in that format:

    <MEDIAINFO>
    General #0
    Complete name : C:\mymovie\myvideo.avi
    Format : AVI
    Format/Info : Audio Video Interleave
    Format/Family : RIFF
    File size : 215 MiB
    PlayTime : 23mn 54s
    Bit rate : 1257 Kbps
    StreamSize : 4.03 MiB
    Writing library : VirtualDub build 23350/release
    Comment : CRC32F03A683F3

    Video #0
    Codec : XviD
    Codec/Family : MPEG-4V
    Codec/Info : XviD project
    Codec profile : Streaming Video Profile/Level 1
    Codec settings, Packet bitst : Yes
    Codec settings, BVOP : Yes
    Codec settings, QPel : No
    Codec settings, GMC : 3
    Codec settings, Matrix : Default
    PlayTime : 23mn 54s
    Bit rate : 1041 Kbps
    Width : 704 pixels
    Height : 396 pixels
    Display Aspect ratio : 16/9
    Frame rate : 59.959 fps
    Resolution : 8 bits
    Chroma : 4:2:0
    Interlacement : Progressive
    Bits/(Pixel*Frame) : 0.062
    StreamSize : 178 MiB

    Audio #0
    Codec : MPEG-1 Audio layer 3
    PlayTime : 23mn 54s
    Bit rate mode : CBR
    Bit rate : 192 Kbps
    Channel(s) : 2 channels
    Sampling rate : 48 KHz
    Resolution : 16 bits
    Video0 delay : 24ms
    StreamSize : 32.8 MiB
    Writing library : Gogo (after 3.0)
    </MEDIAINFO>
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  5. The script you gave should work. You don't need the ChangeFPS() command since the video is already 59.94 fps.

    Your 20 fps video could be encoded at 20 fps progressive MPEG2 and then have pulldown flags added with DGPulldown. That would give better quality.

    None of what you are doing changes the running time of the video so there's no need to adjust the audio.
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  6. Your 20 fps video could be encoded at 20 fps progressive MPEG2 and then have pulldown flags added with DGPulldown.
    Right, except no encoder I know of will actually encode for 20fps. When I have silent films at 19.98fps, I encode for 23.976fps and then run the result through DGPulldown set for 19.98->29.97fps.

    I also raise all my bitrates by a factor of 23.976/19.98=1.2 so the sizes and max/min bitrates come out correct. And, as you say, since the lengths remain the same no audio stretching has to be done.
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  7. Originally Posted by manono
    no encoder I know of will actually encode for 20fps
    You're right. I keep forgetting that MPEG only allows certain frame rates. And 20 fps isn't one of them.
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  8. Member
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    Originally Posted by jagabo
    The script you gave should work. You don't need the ChangeFPS() command since the video is already 59.94 fps.

    Your 20 fps video could be encoded at 20 fps progressive MPEG2 and then have pulldown flags added with DGPulldown. That would give better quality.

    None of what you are doing changes the running time of the video so there's no need to adjust the audio.
    Jagabo, yes it does work and yes, I removed the ChangeFPS, but what I am trying to figure out is how I would accomplish the conversion if I wanted to encode the audio and video separately.

    I personally do not like using CCE to encode the audio.
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  9. Always Watching guns1inger's Avatar
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    Load the avs script into virtualdub and save a WAV file
    Read my blog here.
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  10. Member
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    Originally Posted by guns1inger
    Load the avs script into virtualdub and save a WAV file
    Do you mean under "File save as" or go into the stream list? I am assuming I use "Direct Steam Copy"? Also, is there a way this can be done using a command line such as ffmpeg or mencoder?
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  11. Always Watching guns1inger's Avatar
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    In Virtualdub there is a Save WAV option under the File menu.
    Read my blog here.
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  12. If you Save WAV from VirtualDub in Audio -> Direct Stream Copy mode and your audio is compressed you will end up with a WAV file of compressed audio. A WAV file with MP3 compressed audio, for example. If you enable Audio -> Full Processing mode you will end up with uncompressed audio.

    If you use VirtualDubMod you can demux the audio into its native container, MP2, MP3, AC3, etc. Streams -> Stream List -> Demux
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  13. Always Watching guns1inger's Avatar
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    This is audio from an avisynth script - would it not be uncompressed, as that is what avisynth serves by default ?
    Read my blog here.
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  14. Originally Posted by guns1inger
    This is audio from an avisynth script - would it not be uncompressed, as that is what avisynth serves by default ?
    Sorry, I forgot he was using an AviSynth script. Yes, the audio would be uncompressed in that case because AviSynth will feed uncompressed audio to VirtualDub.
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  15. Member
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    Thanks fellas.

    Also, is there a way I can do this using a command line utility?
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  16. Member
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    With these installed. Or later versions.

    BeSweetv1.5b31.zip
    http://kurtnoise.free.fr/index.php?dir=BeLight/&file=bsn_20070513.zip -> bsn.dll copied into the BeSweet folder
    aften-svn-r683-icl10_1-win32-bin.zip -> aften.exe copied into the BeSweet folder

    All of the following will work. Code go on a single line. No wordwrap. Change path names to reflect your program locations. I save as Avcd.cmd, Amp3.cmd & Aac3.cmd. Reminds me that the command file only deals with the audio.

    Extract audio from an AVI and output as mpg @ 44100. Used for creating a VCD.
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.mp3" ) -ota( ) -ssrc( --rate 44100 ) -toolame( -m s -b 128 )
    Extract audio from an AVI and output as AC3
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.ac3" ) -ota( ) -ssrc( --rate 48000 ) -bsn( -exe aften.exe -b 224 )
    Extract audio from an AVI and output as MP3.
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.mp3" ) -lame( -b 192 )
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  17. Member
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    Originally Posted by pcspeak
    With these installed. Or later versions.

    BeSweetv1.5b31.zip
    http://kurtnoise.free.fr/index.php?dir=BeLight/&file=bsn_20070513.zip -> bsn.dll copied into the BeSweet folder
    aften-svn-r683-icl10_1-win32-bin.zip -> aften.exe copied into the BeSweet folder

    All of the following will work. Code go on a single line. No wordwrap. Change path names to reflect your program locations. I save as Avcd.cmd, Amp3.cmd & Aac3.cmd. Reminds me that the command file only deals with the audio.

    Extract audio from an AVI and output as mpg @ 44100. Used for creating a VCD.
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.mp3" ) -ota( ) -ssrc( --rate 44100 ) -toolame( -m s -b 128 )
    Extract audio from an AVI and output as AC3
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.ac3" ) -ota( ) -ssrc( --rate 48000 ) -bsn( -exe aften.exe -b 224 )
    Extract audio from an AVI and output as MP3.
    Code:
    "C:\VidAud\Besweet\BeSweet.exe" -core( -input "video.avi" -output "audio.mp3" ) -lame( -b 192 )
    Thanks for the response. I will look into this.
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