[Libav-user] How to specify output format

jim morgenstern jmorgie at yahoo.com
Mon Jan 21 17:01:17 CET 2013


Paul
Thanks for the specifics.  I don't like headerless so .raw and .yuv are out.

Hadn't heard of .nut;  I don't understand your comment about -vcodec etc.
I am writing a C++ app not using the command line utilities.

So what all do I need to know about .nut?  Googled but cannot find any
definitions or spec for the file.  Can you send a url?



> -----Original Message-----
> From: libav-user-bounces at ffmpeg.org [mailto:libav-user-bounces at ffmpeg.org]
> On Behalf Of Paul B Mahol
> Sent: Monday, January 21, 2013 10:41 AM
> To: This list is about using libavcodec, libavformat, libavutil,
libavdevice and
> libavfilter.
> Subject: Re: [Libav-user] How to specify output format
> 
> On 1/21/13, jim morgenstern <jmorgie at yahoo.com> wrote:
> > So what Specifically is the specific format extension that I give to
> > ffmpeg that gives me the "raw video format" you cited?
> 
> Headerless : .raw, .yuv (You need to remember pixel format and dimensions
> stored in it)
> 
> With headers : .nut (You must use -vcodec rawvideo and -pix_fmt same as
your
> input video
>                      to keep video uncompressed)
>     There are others like .avi, .. but they may not support pixel format
of your
> input video.
> 
> >
> >> -----Original Message-----
> >> From: libav-user-bounces at ffmpeg.org
> >> [mailto:libav-user-bounces at ffmpeg.org]
> >> On Behalf Of Paul B Mahol
> >> Sent: Monday, January 21, 2013 9:50 AM
> >> To: This list is about using libavcodec, libavformat, libavutil,
> > libavdevice and
> >> libavfilter.
> >> Subject: Re: [Libav-user] How to specify output format
> >>
> >> On 1/21/13, jim morgenstern <jmorgie at yahoo.com> wrote:
> >> >>> where can I find the list of formats and their extensions?
> >> >> In the source code
> >> >
> >> > Yes but the source code is hundreds of files;  can you tell me
> >> > which one has the list and the mapping?
> >> >
> >> >
> >> >> > .       What is your recommended format for uncompressed HD video
?
> >> >>
> >> >> libx264 is the state of the art encode
> >> >
> >> > But I do not want any encoding or compression:  I want flat file
> >> > that can be read later on for more processing.  So is there a
> >> > recommendation for a particular file format that does this?
> >>
> >> Depends on what you gonna use for more processing later.
> >> Depending on available storage and CPU speed you could use raw video
> >> formats...
> >>
> >> >
> >> >
> >> >
> >> >
> >> >> -----Original Message-----
> >> >> From: libav-user-bounces at ffmpeg.org
> >> >> [mailto:libav-user-bounces at ffmpeg.org]
> >> >> On Behalf Of Stefano Sabatini
> >> >> Sent: Monday, January 21, 2013 7:50 AM
> >> >> To: This list is about using libavcodec, libavformat, libavutil,
> >> > libavdevice and
> >> >> libavfilter.
> >> >> Subject: Re: [Libav-user] How to specify output format
> >> >>
> >> >> In data Saturday 2013-01-19 01:55:22 -0500, Jim Morgenstern ha
> >> >> scritto:
> >> >> > I have C++ app [win 7]  that is reading and writing video/audio
> > stream.
> >> >> >
> >> >> >
> >> >> >
> >> >> > When I specify the output file as xxxx.MOV I am getting H264
> >> >> > compressed video at 24 fps.
> >> >> >
> >> >> >
> >> >> >
> >> >> > I want to have output as uncompressed at 30 or 60 fps according
> >> >> > to the input.
> >> >> >
> >> >> >
> >> >> >
> >> >> > Some simple [I hope] questions:
> >> >> >
> >> >> > .       What is [where can I find] the mapping between file name
> >> > extension
> >> >> > and format used?
> >> >>
> >> >> In the source code, or you can show the ".extensions" field for
> >> >> all the
> >> > registered
> >> >> AVInput/OutputFormats.
> >> >>
> >> >> >
> >> >> > .       Can I specify the output format I want rather than using
> >> >> > av_guess_format ?  all the tutorials use guess
> >> >>
> >> >> Yes, you need to specify avformat_alloc_output_context2() and rely
> >> >> on oformat/format_name parameters, or use av_guess_format().
> >> >>
> >> >> >
> >> >> > .       What is your recommended format for uncompressed HD video
?
> >> >>
> >> >> libx264 is the state of the art encoder (but it has licensing
> >> > constraints).
> >> >> _______________________________________________
> >> >> Libav-user mailing list
> >> >> Libav-user at ffmpeg.org
> >> >> http://ffmpeg.org/mailman/listinfo/libav-user
> >> >
> >> > _______________________________________________
> >> > Libav-user mailing list
> >> > Libav-user at ffmpeg.org
> >> > http://ffmpeg.org/mailman/listinfo/libav-user
> >> >
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> >
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