[Libav-user] How to specify output format

Paul B Mahol onemda at gmail.com
Mon Jan 21 19:06:18 CET 2013


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
>> >
>> _______________________________________________
>> 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