[Libav-user] How to specify output format

jim morgenstern jmorgie at yahoo.com
Mon Jan 21 18:58:28 CET 2013


Paul -- couple of problems

I did as you suggested and specified the output file as:  *.nut
**  ffmpeg associates the MPEG4 codec with this output and I want
uncompressed
**  the audio stream bombs

Thanks for any help you can provide

Here is a code snippet, then screen output from ffmpeg:
=========

    m_pOutputFormat = av_guess_format(NULL, filename, NULL);
    m_pFormatContext = avformat_alloc_context();
    m_pFormatContext->oformat = m_pOutputFormat;
    _snprintf_s(m_pFormatContext->filename,
sizeof(m_pFormatContext->filename), "%s", filename);

// add the audio and video streams using the default format codecs and
initialize the codecs.
    m_pAudioStream = NULL;
    if (m_pOutputFormat->audio_codec != CODEC_ID_NONE) 
   {
        m_pAudioStream = add_audio_stream(m_pFormatContext,
m_pOutputFormat->audio_codec, channels);
    }
// and the abort comes from add_audio_stream
==================

Starting MediaFileIO for D:\Data\Solavei.mov

[mov,mp4,m4a,3gp,3g2,mj2 @ 00ad3320] Stream #1: not enough frames to
estimate ra
te; consider increasing probesize
[mov,mp4,m4a,3gp,3g2,mj2 @ 00ad3320] Stream #2: not enough frames to
estimate ra
te; consider increasing probesize

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'D:\Data\Solavei.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-07-12 23:41:43
  Duration: 00:00:11.81, start: 0.000000, bitrate: 598161 kb/s
    Stream #0:0(eng): Video: v210 (v210 / 0x30313276), yuv422p10le,
1280x720, 59
6600 kb/s, SAR 1:1 DAR 16:9, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc
    Metadata:
      creation_time   : 2012-07-12 23:41:43
      handler_name    : Apple Alias Data Handler
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz,
stereo, s1
6, 1536 kb/s
    Metadata:
      creation_time   : 2012-07-12 23:41:43
      handler_name    : Apple Alias Data Handler
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74)
    Metadata:
      creation_time   : 2012-07-12 23:42:01
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:28;11
	 
	 
Starting MediaFileIO for => D:\Data\TestSol.nut
Output #0, nut, to 'D:\Data\TestSol.nut':
    Stream #0:0: Video: mpeg4, yuv420p, 1280x720, q=2-31, 5942 kb/s, 90k
tbn, 29
 tbc
    Stream #0:1: Audio: vorbis, 44100 Hz, 1 channels, s16, 64 kb/s
[libvorbis @ 054e20c0] Specified sample_fmt is not supported.

File Initialization Exception: output !!  
 MediaFileWriter::open_audio: Could not open audio codec   //this is my app
error message





> -----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 11:26 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:
> > 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.
> 
> I mean video codec should be set to rawvideo. And pixel format for that
codec
> should be same as one detected in input.
> 
> >
> > 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?
> 
> You really should not need know anything, you just set output format to
nut and
> it is all what is needed. I doubt you want nut spec if you gonna use
libavformat to
> read nut files.
> 
> >
> >
> >
> >> -----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
> >> >> >
> >> >> _______________________________________________
> >> >> 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
> >> >
> >> _______________________________________________
> >> 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
> >
> _______________________________________________
> Libav-user mailing list
> Libav-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/libav-user



More information about the Libav-user mailing list