[Libav-user] Hardware accell encoding

Leandro Raffo ljraffo at gmail.com
Sat Sep 10 00:17:53 EEST 2016

2016-09-09 15:59 GMT-03:00 Charles <linux2 at orion15.org>:
>> I'm trying to encode AVFrames using the GPU from C code, so I was
>> trying to see how ffmpeg's source code was doing it and asking for a
>> pointer on it (or its location lol). I've already encoded directly
>> with ffmpeg (to see its working) but I need to encode random AVFrames
>> not an entire video. Also giving a yuv420 video to the Nvidia ENC
>> samples produces a corrupted video.
> nvenc is going to encode yuv video into h264 stream, I am not sure the
> output format is what you want.
> To get "random" frames encoded, you will have to do something like GOP=1 and
> mark all frames key frames somehow.
> Sounds like you are trying to create a slide show from random frames in a
> video stream?
> Pure theory YMMV...
> If you want to use nvenc directly you need to transform AVFrame to
> EncodeFrameConfig
> See
> NVENCSTATUS CNvEncoder::EncodeFrame(EncodeFrameConfig *pEncodeFrame, bool
> bFlush, uint32_t width, uint32_t height)
> Should be able to create your own convertAvFrametoEncoded
> REF: convertYUVpitchtoNV12 convertYUVpitchtoYUV444
> Setting ecoded->yuv[0], encoded->yuv[1], encoded->yuv[2], dstwidth,
> dstheight from
> av_frame->data[0] av_frame->data[1] av_frame->data[2], av_frame->width,
> av_frame->height, av_frame->linesize
> but I think the output will not be a "VIDEO FRAME"
> Thanks
> cco

I have RGB images of a video that I was converting to AVFrames and I
wanted to encode in real time without incurring in heavy CPU usage.
Basically offload the hard part to the GPU. I thought ffmpeg api would
expose some kind of  functionality for this (I've seen code doing
decoding with VDPAU). I'll keep checking the nvidia examples( I was
avoiding them mainly because of the amount of boilerplate that I don't
have a clue what is doing and because it encoded garbage.) and see If
I can do it with your pointers. Thanks!

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