[Libav-user] How to specify output format
jim morgenstern
jmorgie at yahoo.com
Mon Jan 21 21:27:20 CET 2013
So this is the piece to the puzzle I am missing:
* where does one set the output pixel format / video codec to
CODEC_ID_RAWVIDEO ?
I have
> > m_pOutputFormat = av_guess_format(NULL, filename, NULL);
> > m_pFormatContext = avformat_alloc_context();
> > m_pFormatContext->oformat = m_pOutputFormat;
So after I get a format context then I can go in and tweak the various
fields?
Sure wish someone would write a book
Thanks
> -----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 1:06 PM
> 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 -- 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
>
> I said you must set video codec to rawvideo aka CODEC_ID_RAWVIDEO.
>
> >
> > 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
>
> You want to store audio? If yes. What codec?
>
>
> >
> >
> >
> >
> >
> >> -----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
> >> >
> >> _______________________________________________
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> >> http://ffmpeg.org/mailman/listinfo/libav-user
> >
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> > http://ffmpeg.org/mailman/listinfo/libav-user
> >
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