DGPulldown Help

[Maikeru-sama]

I have an MP4 file that is 60 FPS.

Naturally, I encoded it using Avisynth and specifically the AssumeFPS(60) function.

When I attempt to put a pulldown on the file (60->29.97) I get the following error: "target/current rate must not be less than 1.0".

Any ideas?

[guns1inger]

You can't use pulldown to reduce the number of frames. Pulldown is only valid for creating new frames on-the-fly. You will have to reduce the number of frames to get a framerate of 29.970 or less before you encode to mpeg-2.

[Maikeru-sama]

You can't use pulldown to reduce the number of frames. Pulldown is only valid for creating new frames on-the-fly. You will have to reduce the number of frames to get a framerate of 29.970 or less before you encode to mpeg-2.

So how would I do that?

[guns1inger]

To be honest, not something I have had to woprry about. There are various decimate filters etc for tools like avisynth and virtualdub, but it has to be done carefully or you will get all sorts of nasty artifacts.

Someone like Manono is probably better placed to give you detailed (and correct) advice on this. I know the theory, just never had to put it into practice.

I suspect if you do some searching or browsing through the HD/DV forum you will find posts that discuss it more fully.

[manono]

It's really 60fps and not 59.94fps?

You can either drop the in-between frames to make it progressive 29.97fps, or interlace it, also at 29.97fps. In neither case will pulldown be needed. For the former either:

SelectEven() #if really 59.94fps originally, or

ChangeFPS(29.97)

For the latter:

ChangeFPS(59.94) #if really 60fps originally
AssumeTFF()
SeparateFields()
SelectEvery(4,0,3)
Weave()

Interlacing it should make for smoother playback and make the one extra dropped frame in 1001 (if it was 60fps) less noticeable.

[Maikeru-sama]

Manono, I encoded the 60 fps script using Quenc and the audio and video are out of sync. Any ideas? Let me know. I will try the 59.94 script because as you can see below, Mediainfo is saying it is 59.94 but Mplayer says 60 fps and based on my knowledge Mplayer has always seemed to be more accurate than Mediainfo.

ChangeFPS(59.94) #if really 60fps originally 
AssumeTFF() 
SeparateFields() 
SelectEvery(4,0,3) 
Weave()

General #0
Complete name                : Cowboys at Browns.mp4
Format                       : MPEG-4
Format/Info                  : ISO 14496-1 version 2
Format/Family                : MPEG-4
File size                    : 1.41 GiB
PlayTime                     : 1h 59mn
Bit rate                     : 1689 Kbps
StreamSize/String            : 7.98 MiB
Encoded date                 : UTC 2008-09-08 03:13:26
Tagged date                  : UTC 2008-09-08 08:17:57
Encoded_application          : HandBrake 0.9.2 2008022300

Video #0
Codec                        : AVC
Codec/Family                 : AVC
Codec/Info                   : Advanced Video Codec
Codec profile                : Main@L5.1
Codec settings, CABAC        : Yes
Codec_Settings_RefFrames     : 5
PlayTime                     : 1h 59mn
Bit rate mode                : VBR
Bit rate                     : 1600 Kbps
Width                        : 768 pixels
Height                       : 432 pixels
Display Aspect ratio         : 16/9
Frame rate mode              : VFR
Frame rate                   : 59.940 fps
Minimum frame rate           : 59.850 fps
Maximum frame rate           : 60.000 fps
Chroma                       : 4:2:0
Interlacement                : Progressive
Bits/(Pixel*Frame)           : 0.080
StreamSize/String            : 1.33 GiB
Encoded date                 : UTC 2008-09-08 03:13:26
Tagged date                  : UTC 2008-09-08 08:17:57

Audio #0
Codec                        : AAC LC
Codec/Family                 : AAC
Codec/Info                   : AAC Low Complexity
PlayTime                     : 1h 59mn
Bit rate mode                : VBR
Bit rate                     : 80.0 Kbps
Maximum bit rate             : 114 Kbps
Channel(s)                   : 2 channels
Channel positions            : L R
Sampling rate                : 48.0 KHz
Resolution                   : 16 bits
StreamSize/String            : 68.2 MiB
Encoded date                 : UTC 2008-09-08 03:13:26
Tagged date                  : UTC 2008-09-08 08:17:57

[jagabo]

And if it's a movie you want to decimate back to 23.976 fps film frames and encode with pulldown flags.

[manono]

Manono, I encoded the 60 fps script using Quenc and the audio and video are out of sync. Any ideas?

No, since nothing I gave you changed the length of the video. I don't know what you did in the encoder.

[Maikeru-sama]

I had audio/video sync problems after encoding the video and assuming that it is 59.94. Below is the code that I used to encode the MP4 file. I have attached the settings I have used for Quenc. Should I be calling a Avisynth function to force audio synchronization? I may try with HCenc, but I don't know what to do for the audio.

DirectShowSource("D:\Cowboys at Browns.mp4")
LanczosResize(720,480,88,0,592,432)
SelectEven()
ChangeFPS(29.97)

[45tripp]

DirectShowSource("D:\Cowboys at Browns.mp4",convertfps=true,fps=29.97)

[Alex_ander]

There is a more reliable (than DirectShowSource) way of importing your video into AviSynth. Since the video stream here is AVC (h264), you can demux it with YAMB to raw .h264 file and use DGAVCIndex to create .dga frame index file. Using this file via AVCSource() prevents any unexpected frame dropping or even forced deinterlacing (by a Direct Show filter on your system) while importing. Then you can explore the video type and in case there are no repeated frames, do interlacing as suggested; if film, then decimate. Audio (raw .aac from YAMB) should be processed separately in this case, e.g. decompressed to .wav with GraphEdit or some converter/ audio editor.

[Maikeru-sama]

DirectShowSource("D:\Cowboys at Browns.mp4",convertfps=true,fps=29.97)

Thanks 45Tripp, this worked like a charm.

[Maikeru-sama]

There is a more reliable (than DirectShowSource) way of importing your video into AviSynth. Since the video stream here is AVC (h264), you can demux it with YAMB to raw .h264 file and use DGAVCIndex to create .dga frame index file. Using this file via AVCSource() prevents any unexpected frame dropping or even forced deinterlacing (by a Direct Show filter on your system) while importing. Then you can explore the video type and in case there are no repeated frames, do interlacing as suggested; if film, then decimate. Audio (raw .aac from YAMB) should be processed separately in this case, e.g. decompressed to .wav with GraphEdit or some converter/ audio editor.

Does YAMB have a CLI?

[jagabo]

Does YAMB have a CLI?

Yamb is a GUI for MP4Box.exe.