[FFmpeg-user] Please can someone tell me why this ffmpeg command stopped working

dE . de.techno at gmail.com
Sat Jan 28 13:20:01 CET 2012

On 01/28/12 22:41, Paul Gardiner wrote:
> On 28/01/2012 16:49, Reindl Harald wrote:
>> Am 28.01.2012 17:33, schrieb Paul Gardiner:
>>> On 28/01/2012 16:24, Paul Gardiner wrote:
>>>> On 28/01/2012 16:10, Reindl Harald wrote:
>>>>> Am 28.01.2012 16:53, schrieb Paul Gardiner:
>>>>>> Can anybody see what is wrong with this:
>>>>>> /usr/bin/ffmpeg -f ac3 -ar 48000 -i /tmp/mythar4336/audout -f
>>>>>> rawvideo -top 1 -pix_fmt yuv420p -s 1440x1088 -r 25
>>>>>> -i /tmp/mythar4336/vidout -threads 2 -vf
>>>>>> crop=1440:1080:0:0,scale=1280:720 -vcodec libx264 -preset medium 
>>>>>> -crf
>>>>>> 20.0
>>>>>> -bufsize 25000k -maxrate 20000k -aspect 16:9 -acodec copy -f mp4
>>>>>> /home/public/video/Archive/Horizon - Playing God.mp4
>>>>>> Until a recent ffmpeg update, it used to do exactly what I 
>>>>>> wanted, but
>>>>>> now it produces the error message: "Option sample_rate not 
>>>>>> found." I've
>>>>>> googled and found various references to people having to make sure
>>>>>> arguments are in the right order with later versions of ffmpeg, but
>>>>>> my command seems to obey the rules, plus attempts I have made to 
>>>>>> reorder
>>>>>> have not helped.
>>>>> "-f ac3 -ar 48000 -i"
>>>>> why is "-ar" BEFORE the input file?
>>>>> in this case you set the parameter for the input instead the output
>>>> My thinking was that the input was 48kHz and I needed to tell ffmpeg
>>>> that information about the input. I guess that's showing my
>>>> misunderstanding about how it works.
>> i would say ffmpeg is knowing more about the input file as you and i 
>> will
>> ever be able and there may be only very few cases where it needs help
>> the output should specifuied so exactly as possible if you nedd videos
>> palying in iPhone as example to make sure they are H264 BASELINE but
>> not the input (use the ffmpeg output to see what is really is *gg*)
>>>> Off to try the alteration now.
>>> Brilliant! It worked. I am again able to transcode my TV recordings.
>>> I guess I should also move the "-r 25" from before the second 
>>> input-file argument. Is that right?
>> it is quite simple, all parameters before any file are taken as
>> params for exactly this one
> Yes that's completely plain from the documentation, but did you get
> my point that I didn't know whether -ar 48000 should be used to
> tell ffmpeg the sample rate of the input file I was supplying or
> whether it should be used to tell ffmpeg the sample rate I wanted
> in the output file. I know now of course with your help.
> Cheers,
>     Paul.
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Also, I don't think you should use maxrate, last time I checked it 
didn't work with x264. Use -x264opts qp=<a value from 0 (lossless) to 60 
(worst quality)> instead.

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