[MPlayer-users] Mencoder: How to convert 1440x1080 to 1920x1080 Square pixel and yuv420 to yuv244p

Karsten Jeschkies jeskar at web.de
Mon Mar 11 11:40:17 CET 2013

>>* I converted the m2t to an image sequence nad used that as an input for*>>* ffmpeg. However, that screws up the aspect ratio.*>>* *>>* Or should I rather use mencoder to convert to huffyuv and then use the new*>>* file as an input for ffmpeg?*>
>You should really report the FFmpeg issue to them together with a sample
>But otherwise, instead of decoding to images you'd normally use mplayer
>with -vo yuv4mpeg which will preserve frame rate and aspect settings,
>and ideally you'd stream it to ffmpeg via a pipe to not require so much
>disk space.

Hm,I piped the output from mplayer to ffmpeg but now the Codec DNxHD
does not accept the input:

mplayer johannson_hdv_1.m2t -vo yuv4mpeg:file=pipe.fifo

ffmpeg -i pipe.fifo -s 1920x1080 -b:v 36M -pix_fmt yuv422p -vcodec dnxhd

And the output from ffmpeg:

ffmpeg version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the
Libav developers
  built on Jan 24 2013 14:49:20 with gcc 4.7.2
This program is only provided for compatibility and will be removed in a
future release. Please use avconv instead.
[yuv4mpegpipe @ 0x1910ba0] Estimating duration from bitrate, this may be
Input #0, yuv4mpegpipe, from 'pipe.fifo':
  Duration: N/A, bitrate: N/A
    Stream #0.0: Video: rawvideo, yuv420p, 1440x1080, PAR 4:3 DAR 16:9, 25
fps, 25 tbr, 25 tbn, 25 tbc
File 'johannsen_hdv_1.mov' already exists. Overwrite ? [y/N] y
[buffer @ 0x1911c40] w:1440 h:1080 pixfmt:yuv420p
[scale @ 0x1918c80] w:1440 h:1080 fmt:yuv420p -> w:1920 h:1080 fmt:yuv422p
[dnxhd @ 0x1912560] video parameters incompatible with DNxHD
Output #0, mov, to 'johannsen_hdv_1.mov':
    Stream #0.0: Video: dnxhd, yuv422p, 1920x1080 [PAR 1:1 DAR 16:9],
q=2-31, 200 kb/s, 90k tbn, 25 tbc
Stream mapping:
  Stream #0.0 -> #0.0
Error while opening encoder for output stream #0.0 - maybe incorrect
parameters such as bit_rate, rate, width or height

This is kinda strange, since scale should actually yield the right format
for DNxHD. Do I miss something?

best regars,

PS: I am uploading my video file and will post it here so we can see if it
is an error within ffmpeg or something else.

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