[Libav-user] Create a muxer without enc_ctx = out_stream->codec

Charles linux2 at orion15.org
Tue Aug 23 15:22:55 EEST 2016


Thank you for looking.

Yes, I pretty much started there, and pretty much have it open all the time.
 From what I can tell my code is doing the same thing:

    av_encode_codec_ctx = avcodec_alloc_context3( av_encode_codec );
    if ( !av_encode_codec_ctx ) { PRINT_AV_ERROR( "ERROR:avcodec_alloc_context3:" ); return -1; }
    av_encode_codec_ctx->bit_rate    = 5e6;
    av_encode_codec_ctx->width       = 1024;   /// \note multiple of 2
    av_encode_codec_ctx->height      = 768;   /// \note multiple of 2
    av_encode_codec_ctx->time_base   = (AVRational) { 1, 60 }; //* 2;
    av_encode_codec_ctx->gop_size    = 15;      // Intra frames per x P frames
    av_encode_codec_ctx->pix_fmt     = AV_PIX_FMT_YUV420P; // (MUST) DO NOT CHANGE nvenc required

That code does not setup the output with
    avio_open( &av_out_fmt_ctx->pb, f.c_str(), AVIO_FLAG_WRITE )
    avformat_write_header( av_out_fmt_ctx, NULL )

The header is where I see my error, either the muxer is unhappy or the encoder is unhappy

Output #0, mp4, to 'enc.mp4':
     Stream #0:0: Unknown: none (h264_nvenc) ([33][0][0][0] / 0x0021)
av_dump_format enc.mp4
[mp4 @ 0x786d60] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
[mp4 @ 0x786d60] dimensions not set
ERROR:avformat_write_header::

Thanks
cco

On 08/23/2016 07:01 AM, salsaman wrote:
> Charles,
> perhaps the example here can help ?
>
>  https://ffmpeg.org/doxygen/3.1/decoding__encoding_8c_source.html#l00347
>
>
>
>
>
> http://lives-video.com
> https://www.openhub.net/accounts/salsaman
>
> On Tue, Aug 23, 2016 at 8:39 AM, Charles <linux2 at orion15.org <mailto:linux2 at orion15.org>> wrote:
>
>     On 08/23/2016 03:08 AM, Nicolas George wrote:
>
>         Le sextidi 6 fructidor, an CCXXIV, Charles a écrit :
>
>             6 - avcodec_parameters_to_context( av_encode_codec_ctx, av_out_fmt_ctx->streams[ 0 ]->codecpar )
>
>
>         You are copying the parameters from a newly created blank stream to an
>         initialized encoder. That feels wrong.
>
>         Regards,
>
>
>     Thanks for the look, I did some rearranging and I am to the point where the muxer is happy or the encoder is happy but cant get both at
>     the same time:
>
>     Currently Op order:
>     1) av_encode_codec = avcodec_find_encoder( AV_CODEC_ID_H264 )
>     2) avformat_alloc_output_context2( &av_out_fmt_ctx, NULL, NULL, f.c_str() )
>     3) video_st = avformat_new_stream( av_out_fmt_ctx, av_encode_codec )
>        video_st->id = 0;
>        video_st->time_base.den   = 60; // * 2;
>        video_st->time_base.num   = 1;
>        // This solved the time_base error
>     4) parameters = video_st->codecpar;
>        parameters->codec_tag = tag;
>        parameters->format    = AV_PIX_FMT_YUV420P;
>        parameters->bit_rate  = 5e6;
>        parameters->width     = 1024;
>        parameters->height    = 768;
>        parameters->bit_rate  = 5e6;
>        av_dict_set( &av_dict_opts, "b", "2.5M", 0);
>        av_dict_set( &av_dict_opts, "preset", "losslesshp", 0 );
>        av_dict_set( &av_dict_opts, "profile", "high", 0 );
>        av_dict_set( &av_dict_opts, "rc", "vbr_minqp", 0 );
>        av_dict_set( &av_dict_opts, "gpu", "1", 0 );
>     5) av_encode_codec_ctx = avcodec_alloc_context3( av_encode_codec )
>        av_encode_codec_ctx->bit_rate    = 5e6;
>        av_encode_codec_ctx->width       = 1024;   /// \note multiple of 2
>        av_encode_codec_ctx->height      = 768;   /// \note multiple of 2
>        av_encode_codec_ctx->time_base   = (AVRational) { 1, 60 }; //* 2;
>        av_encode_codec_ctx->gop_size    = 15;      // Intra frames per x P frames
>        av_encode_codec_ctx->pix_fmt     = AV_PIX_FMT_YUV420P; // MUST DO NOT CHANGE nvenc required
>        // This appears to make h264_nvenc happy
>     6) avcodec_parameters_to_context( av_encode_codec_ctx, parameters )
>     7) avcodec_open2( av_encode_codec_ctx, av_encode_codec, &av_dict_opts )
>
>     [mp4 @ 0xc2ed60] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
>     [mp4 @ 0xc2ed60] dimensions not set
>
>     AVStream does not have dimensions, and the error makes me think its in the ctx but I am setting those dims.
>
>     Clearly I am not setting something, just haven't found it.
>
>
>     Thanks
>     cco
>
>
>
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