Transcoded x264 choppy on MVP

[mvallevand]

I think this a reasonable digital transcode. After all you are going from 60 fps to 25 fps so I don't think you really can avoid judder and telecine problems. It probably looks worse by changing the aspect ratio.

Martin

[pBS]

run your command and add a ">>file.txt" at the end... [eg: ffmpeg -y -i xxx etc. >>ffmpeg.log]
and it will capture what you normally see and write it to that file...
you might not see anything, as it's all going into that file, but to cancel encode early,hit 'q'..
[that should provide enough details to start with]

oh and since you're doing it from the auto-transcoder, just add " >>transcode.log" to config.xml line
[right before </MVPFFmpegTranscodeCmdLine]
for example on mine [i'm ntsc tho] :

Code:

<MVPFFmpegTranscodeCmdLinePAL>-y -i "{SOURCE_FILE}" -b 2400k -ar 48000 -ac 2 -ab 128 -r 25 -s 352x288 -f svcd "{DEST_FILE}"  &gt;&gt;transcode.log</MVPFFmpegTranscodeCmdLinePAL>

but be aware it'll end up in gbpvr dir, not logs dir..

[zehd]

i have no qualms with xvid video, but on a high def tv then you cant go back from 720p!

Theres no point in having a high def file if i only intend to use it on the MVP, but i dont, i watch most on the high def display. Occasionally I watch a few things in bed (a luxury!) and id love to be able to transcode mkv as easily as avi.

Believe me i would love a PCH-110, but the budget wont allow it, and i do think the MVP is a fantastic bit of kit. Knowing that ive invested a few quid in the server and that it will keep up any slack in transcoding id love to be able to use that power occasionally to avoid having to download or encode my files for occasional mvp use.

P.S - still stuck on creating a log file from the ffmpeg trans2mvp process... :-)

i'll get it

[stu8080]

I think this a reasonable digital transcode. After all you are going from 60 fps to 25 fps so I don't think you really can avoid judder and telecine problems. It probably looks worse by changing the aspect ratio.

Martin

I wasnt sure if that was the best i could expect - i will try keeping the aspect ratio the same and let the mvp show it letterboxed.
Thanks martin

[pBS]

try adding -bf 2 to your transcode line...
i realized this when transcoding 264 blu rays to mpeg as mpeg can only handle 2 but h.264 can have more [and usually does]
so i had weird dropouts...tried everything....-bf 2 fixed it...
i guess it was trying to use same bframes as in source when not specified explicitly...

[zehd]

try adding -bf 2 to your transcode line...
i realized this when transcoding 264 blu rays to mpeg as mpeg can only handle 2 but h.264 can have more [and usually does]
so i had weird dropouts...tried everything....-bf 2 fixed it...
i guess it was trying to use same bframes as in source when not specified explicitly...

Are you adding that to the ffmpeg commandline that was mentioned previous by you?

[stu8080]

Thanks for the input guys - ive tried three things so far, maintaining the 16:9 aspect ratio, retaining the original frame rate and 2 b frames.
So far none of these things has made a difference. Am i the only person who transcodes mkv to mpeg for the MVP? I cant think of any part of the process that would differ from anyone elses - i use supplied ffmpeg, built in transcode, and a PAL MVP, what other factors could influence this, and am i just going to have to accept transcoding mkv isnt going to be ideal (we all hate being nearly there dont we!)

[pBS]

i would try one of the 'tryout' versions as i heard the original guy stopped updating ffmpeg so those are the only 'newer' versions out there and they've been working on BD transcoding [also h.264] so i think they may work better on that type of input...
i'm using FFmpeg-svn-15666...
i forget where to get them, search 'ffmpeg tryouts'


oh and also try -copyts just for laughs...
[copy timestamps]
also there's a -fflags genpts which generates new pts that may help..
[those 2 not to be used together tho]

[zehd]

Thanks for the input guys - ive tried three things so far, maintaining the 16:9 aspect ratio, retaining the original frame rate and 2 b frames.
So far none of these things has made a difference. Am i the only person who transcodes mkv to mpeg for the MVP? I cant think of any part of the process that would differ from anyone elses - i use supplied ffmpeg, built in transcode, and a PAL MVP, what other factors could influence this, and am i just going to have to accept transcoding mkv isnt going to be ideal (we all hate being nearly there dont we!)

Actually not many people are doing it.. Great, you're a trend setter...

It looks like the MKV I downloaded will transcode into MPG, but it's very, very poor frames per seconds, and so if I can't do better (much) than 25-30 fps, you can't do on the fly...

I'm trying to speed things up. I've used VLC as a transcoder. I'm having better success with VLC doing large TS files. Seems like the MKV is giving me grief...

[stu8080]

I have tried about half a dozen different versions, recent unofficial win32 builds, 12665 through to the latest i could find - 15815. None give me any sound, and when trying on command line i get errors about the audio bitrate being set too low (with 15815), it seems to set audio bitrate at 0kb/s and no sound on the resultant mpeg.

There is a log file created but its always empty - next best thing is a screengrab: