Build 5185 Transcoding Doubles Frame Rate!!

Bug report and feature request
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pachow
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Build 5185 Transcoding Doubles Frame Rate!!

Post by pachow » Sat Sep 10, 2011 6:42 pm

Hi,

This problem has been reported as potentially an error in the transcoded file header showing a 2x framerate.

Below are the transcoding parameters: Target = 25 FPS, Transcoded File = 50 FPS.

Regards,
pachow

INPUT FILE
==========
General
Complete name: C:\videos\input.mp4
Format: Flash Video
File size: 98.4 MiB
Duration: 21mn 20s
Overall bit rate: 645 Kbps

Video
Format: AVC
Format/Info: Advanced Video Codec
Format profile: High@L3.0
Format settings, CABAC: Yes
Format settings, ReFrames: 4 frames
Codec ID: 7
Duration: 21mn 20s
Bit rate mode: Variable
Maximum bit rate: 555 Kbps
Width: 640 pixels
Height: 360 pixels
Display aspect ratio: 16:9
Frame rate mode: Constant
Frame rate: 25.000 fps
Standard: Component
Color space: YUV
Chroma subsampling: 4:2:0
Bit depth: 8 bits
Scan type: Progressive

Audio
Format: AAC
Format/Info: Advanced Audio Codec
Format profile: LC
Codec ID: 10
Duration: 21mn 20s
Channel(s): 2 channels
Channel positions: Front: L R
Sampling rate: 44.1 KHz
Compression mode: Lossy


Target Format:
==============
Container: AVI
Muxer: FFmpeg
Video: Xvid
Encoder: Xvidcore
Mode: Avergae Bitrade
Bitrate: 1800 Kbps
Resolution: 720x404
Frame Rate: 25.00 FPS
De-interlace: Auto
Audio: MP3
Encoder: LAME MP3
Bitrate: 192 Kbps
Estimated Size: 303 MB


Output File:
============
General
Complete name: C:\videos\output.avi
Format: AVI
Format/Info: Audio Video Interleave
File size: 221 MiB
Duration: 21mn 19s
Overall bit rate: 1 451 Kbps
Writing application: Lavf53.6.0

Video
ID: 0
Format: MPEG-4 Visual
Format profile: Advanced Simple@L5
Format settings, BVOP: 2
Format settings, QPel: No
Format settings, GMC: No warppoints
Format settings, Matrix: Default (H.263)
Codec ID: XVID
Codec ID/Hint: XviD
Duration: 21mn 19s
Bit rate: 1 262 Kbps
Width: 720 pixels
Height: 404 pixels
Display aspect ratio: 16:9
Frame rate: 50.000 fps
Original frame rate: 25.000 fps
Color space: YUV
Chroma subsampling: 4:2:0
Bit depth: 8 bits
Scan type: Progressive
Compression mode: Lossy
Bits/(Pixel*Frame): 0.087
Stream size: 193 MiB (87%)
Writing library: XviD 63

Audio
ID: 1
Format: MPEG Audio
Format version: Version 1
Format profile: Layer 3
Mode: Joint stereo
Mode extension: MS Stereo
Codec ID: 55
Codec ID/Hint: MP3
Duration: 21mn 19s
Bit rate mode: Variable
Bit rate: 224 Kbps
Channel(s): 2 channels
Sampling rate: 44.1 KHz
Compression mode: Lossy
Stream size: 26.2 MiB (12%)
Alignment: Aligned on interleaves
Interleave, duration: 26 ms (1.31 video frame)

meRobs
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Location: Sydney, Australia

Re: Build 5185 Transcoding Doubles Frame Rate!!

Post by meRobs » Sat Sep 10, 2011 9:35 pm

Thanks for the comment.
However, it would be better if you do a search first OR simply look down the page.
This has been reported already: viewtopic.php?f=28&t=10983
You could have added your post there.
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

pachow
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Posts: 6
Joined: Sun Jan 30, 2011 10:50 am

Re: Build 5185 Transcoding Doubles Frame Rate!!

Post by pachow » Sun Sep 11, 2011 11:46 pm

As I mentioned, this problem has been previously reported.

However, it does not appear to be a simple problem in the file header. Using AVIFRATE to change the value leads to playback problems. E.g. playback duration is doubled, jerky playback and audio/video sync issue.

This problem did not occur in earlier versions of 2011.

Cheers,
Pachow

ladycoder
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Re: Build 5185 Transcoding Doubles Frame Rate!!

Post by ladycoder » Mon Sep 12, 2011 6:44 am

If it is actually adding duplicate frames (!) then try making an extra option -ofps 25 in mencoder if you are using mencoder. Or just use a version that worked.

stanley
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Location: Sydney

Re: Build 5185 Transcoding Doubles Frame Rate!!

Post by stanley » Tue Sep 13, 2011 3:04 pm

MediaCoder is aware of "Frame doubling" when it detects the header contains this property. Some interlaced AVCHD video has this property. It's possible this detection is wrong on some file. You can always override the FPS by specifying a value at Settings->Decoding->Override frame rate.
When things work together, things work.

meRobs
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Location: Sydney, Australia

Re: Build 5185 Transcoding Doubles Frame Rate!!

Post by meRobs » Tue Sep 13, 2011 4:13 pm

Stanley: I tried your suggestion for encoding an NTSC VOB file (ie MPEG2 video) to Xvid/AVI.
It failed. The ouput file still shows 59.94 fps as before (twice the NTSC rate).

This always fails for Xvid/AVI.
See the BUG Report at: viewtopic.php?f=28&t=10983
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

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