Thanks for the response Mark! I might be misreading the source code, but for decoding, doesn't vaapi_decode_init do all the heavy lifting? It seems to already call the functions and sets the variables you mentioned.
So might the code be just: avcodec_open2(codecCtx, codec,NULL); vaapi_decode_init(codecCtx); On Fri, 2 Dec 2016, at 09:03 PM, Mark Thompson wrote: > On 02/12/16 10:57, Victor dMdB wrote: > > I was wondering if there were any examples of implementations with > > avformatcontext? > > > > I've looked at the source of ffmpeg vaapi implementation: > > https://www.ffmpeg.org/doxygen/trunk/ffmpeg__vaapi_8c_source.html > > > > and there is a reference to the cli values here > > https://ffmpeg.org/pipermail/ffmpeg-user/2016-May/032153.html > > > > But I'm not really sure how one actually implements the it within either > > decoding or encoding pipeline? > > Start by making an hwdevice. This can be done with > av_hwdevice_ctx_create(), or if you already have a VADisplay (for > example, to do stuff in X via DRI[23]) you can use > av_hwdevice_ctx_alloc() followed by av_hwdevice_ctx_init(). > > For a decoder: > > Make the decoder as you normally would for software. You must set an > AVCodecContext.get_format callback. > Start feeding data to the decoder. > Once enough there is enough data to determine the output format, the > get_format callback will be called (this will always happen before any > output is generated). > The callback has a set of possible formats to use, this will contain > AV_PIX_FMT_VAAPI if your stream is supported (note that not all streams > are supported for a given decoder - for H.264 the hwaccel only supports > YUV 4:2:0 in 8-bit depth). > Make an hwframe context for the output frames and a struct vaapi_context > containing a decode context*. See ffmpeg_vaapi.c:vaapi_decode_init() and > its callees for this part. > Attach your new hwframe context (AVCodecContext.hw_frames_ctx) and decode > context (AVCodecContext.hwaccel_context) to the decoder. > Once you return from the callback, decoding continues and will give you > AV_PIX_FMT_VAAPI frames. > If you need the output frames in normal memory rather than GPU memory, > you can copy them back with av_hwframe_transfer_data(). > > For an encoder: > > Find an hwframe context to use as the encoder input. For a transcode > case this can be the one from the decoder above, or it could be output > from a filter like scale_vaapi. If only have frames in normal memory, > you need to make a new one here. > Make the encoder as you normally would (you'll need to get the codec by > name (like "h264_vaapi"), because it will not choose it by default with > just the ID), and set AVCodecContext.hw_frames_ctx with your hwframe > context. > Now feed the encoder with the AV_PIX_FMT_VAAPI frames from your hwframe > context. > If you only have input frames in normal memory, you will need to upload > them to GPU memory in the hwframe context with av_hwframe_transfer_data() > before giving them to the encoder. > > > - Mark > > > * It is intended that struct vaapi_context will be deprecated completely > soon, and this part will not be required (lavc will handle that context > creation). > > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
