[Libav-user] how to change x264 parameters after opening the encoder (avcodec_open2)

Mohamed Moanis mohamed_moanis at outlook.com
Sun Jul 19 17:58:48 CEST 2015

> From: jennifer.li at zenith.com
> To: libav-user at ffmpeg.org
> Date: Wed, 15 Jul 2015 18:19:18 -0400
> Subject: [Libav-user] how to change x264 parameters after opening the encoder (avcodec_open2)
> I decode and re encode I frame of a movie  file.
> when encode I frame, each I frame need a different qp value. 
> How can qp parameter change after
> avcodec_open2(CodecCtx, codec, &options) )     ? 
> av_dict_set( &options, "qp"   ,  x     , 0 )  is used to set qp.
> If x264 parameter can't change after avcodec_open2 function, 
> Can I close this encoder and open a new x264 encoder with a new parameter for next I frame?
> Thanks
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> Libav-user mailing list
> Libav-user at ffmpeg.org
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From the documentation of avcodec_open2Always call this function before using decoding routines .
So you can't change the parameters after calling the avcodec_open2
For the second question, of course you can close one and reopen another one. 		 	   		  
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